Compare commits

..

1 Commits

Author SHA1 Message Date
Spring Builds ab5a6a5e48 Release v5.3.16 2022-02-17 07:33:24 +00:00
6507 changed files with 202590 additions and 321145 deletions
-32
View File
@@ -1,32 +0,0 @@
name: Backport Bot
on:
issues:
types: [labeled]
pull_request:
types: [labeled]
push:
branches:
- '*.x'
permissions:
contents: read
jobs:
build:
permissions:
contents: read
issues: write
pull-requests: write
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v3
- uses: actions/setup-java@v3
with:
distribution: 'temurin'
java-version: '17'
- name: Download BackportBot
run: wget https://github.com/spring-io/backport-bot/releases/download/latest/backport-bot-0.0.1-SNAPSHOT.jar
- name: Backport
env:
GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
GITHUB_EVENT: ${{ toJSON(github.event) }}
run: java -jar backport-bot-0.0.1-SNAPSHOT.jar --github.accessToken="$GITHUB_TOKEN" --github.event_name "$GITHUB_EVENT_NAME" --github.event "$GITHUB_EVENT"
-32
View File
@@ -1,32 +0,0 @@
name: Deploy Docs
on:
push:
branches-ignore: [ gh-pages ]
tags: '**'
repository_dispatch:
types: request-build-reference # legacy
schedule:
- cron: '0 10 * * *' # Once per day at 10am UTC
workflow_dispatch:
permissions:
actions: write
jobs:
build:
runs-on: ubuntu-latest
if: github.repository_owner == 'spring-projects'
steps:
- name: Checkout
uses: actions/checkout@v3
with:
ref: docs-build
fetch-depth: 1
- name: Dispatch (partial build)
if: github.ref_type == 'branch'
env:
GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
run: gh workflow run deploy-docs.yml -r $(git rev-parse --abbrev-ref HEAD) -f build-refname=${{ github.ref_name }}
- name: Dispatch (full build)
if: github.ref_type == 'tag'
env:
GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
run: gh workflow run deploy-docs.yml -r $(git rev-parse --abbrev-ref HEAD)
@@ -1,13 +1,10 @@
name: "Validate Gradle Wrapper"
on: [push, pull_request]
permissions:
contents: read
jobs:
validation:
name: "Validation"
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v3
- uses: actions/checkout@v2
- uses: gradle/wrapper-validation-action@v1
+14 -21
View File
@@ -1,41 +1,35 @@
# Miscellaneous
*.java.hsp
*.sonarj
*.sw*
.DS_Store
.settings
.springBeans
bin
build.sh
integration-repo
ivy-cache
argfile*
activemq-data/
classes/
# Log files
jxl.log
jmx.log
derby.log
# Gradle artifacts
spring-test/test-output/
.gradle
.gradletasknamecache
argfile*
pom.xml
activemq-data/
classes/
/build
buildSrc/build
/spring-*/build
/framework-*/build
/spring-core/kotlin-coroutines/build
/framework-bom/build
/integration-tests/build
/src/asciidoc/build
spring-test/test-output/
# Maven artifacts
pom.xml
/target/
target/
# Eclipse artifacts, including WTP generated manifests
bin
.classpath
.project
.settings
.springBeans
spring-*/src/main/java/META-INF/MANIFEST.MF
# IDEA artifacts and output dirs
@@ -46,8 +40,7 @@ spring-*/src/main/java/META-INF/MANIFEST.MF
out
test-output
atlassian-ide-plugin.xml
.gradletasknamecache
# VS Code
.vscode/
cached-antora-playbook.yml
.vscode/
+23
View File
@@ -0,0 +1,23 @@
Juergen Hoeller <jhoeller@pivotal.io> jhoeller <jhoeller@vmware.com>
<jhoeller@pivotal.io> <jhoeller@vmware.com>
<jhoeller@pivotal.io> <jhoeller@gopivotal.com>
<rstoyanchev@pivotal.io> <rstoyanchev@vmware.com>
<rstoyanchev@pivotal.io> <rstoyanchev@gopivotal.com>
<pwebb@pivotal.io> <pwebb@vmware.com>
<pwebb@pivotal.io> <pwebb@gopivotal.com>
<cbeams@pivotal.io> <cbeams@vmware.com>
<cbeams@pivotal.io> <cbeams@gopivotal.com>
<cbeams@pivotal.io> <cbeams@gmail.com>
<apoutsma@pivotal.io> <apoutsma@vmware.com>
<apoutsma@pivotal.io> <apoutsma@gopivotal.com>
<apoutsma@pivotal.io> <poutsma@mac.com>
<ogierke@pivotal.io> <ogierke@vmware.com>
<ogierke@pivotal.io> <ogierke@gopivotal.com>
<dsyer@pivotal.io> <dsyer@vmware.com>
<dsyer@pivotal.io> <dsyer@gopivotal.com>
<dsyer@pivotal.io> <david_syer@hotmail.com>
<aclement@pivotal.io> <aclement@vmware.com>
<aclement@pivotal.io> <aclement@gopivotal.com>
<aclement@pivotal.io> <andrew.clement@gmail.com>
<dmitry.katsubo@gmail.com> <dmitry.katsubo@gmai.com>
Nick Williams <nicholas@nicholaswilliams.net> Nicholas Williams <nicholas@nicholaswilliams.net>
-3
View File
@@ -1,3 +0,0 @@
# Enable auto-env through the sdkman_auto_env config
# Add key=value pairs of SDKs to use below
java=17.0.8.1-librca
+14 -18
View File
@@ -6,7 +6,7 @@ First off, thank you for taking the time to contribute! :+1: :tada:
* [Code of Conduct](#code-of-conduct)
* [How to Contribute](#how-to-contribute)
* [Ask questions](#ask-questions)
* [Discuss](#discuss)
* [Create an Issue](#create-an-issue)
* [Issue Lifecycle](#issue-lifecycle)
* [Submit a Pull Request](#submit-a-pull-request)
@@ -22,10 +22,11 @@ Please report unacceptable behavior to spring-code-of-conduct@pivotal.io.
### How to Contribute
#### Ask questions
#### Discuss
If you have a question, check Stack Overflow using
[this list of tags](https://stackoverflow.com/questions/tagged/spring+or+spring-mvc+or+spring-aop+or+spring-jdbc+or+spring-transactions+or+spring-annotations+or+spring-jms+or+spring-el+or+spring-test+or+spring+or+spring-remoting+or+spring-orm+or+spring-jmx+or+spring-cache+or+spring-webflux?tab=Newest). Find an existing discussion, or start a new one if necessary.
[this list of tags](https://stackoverflow.com/questions/tagged/spring+or+spring-mvc+or+spring-aop+or+spring-jdbc+or+spring-transactions+or+spring-annotations+or+spring-jms+or+spring-el+or+spring-test+or+spring+or+spring-remoting+or+spring-orm+or+spring-jmx+or+spring-cache+or+spring-webflux?tab=Newest).
Find an existing discussion, or start a new one if necessary.
If you believe there is an issue, search through
[existing issues](https://github.com/spring-projects/spring-framework/issues) trying a
@@ -38,18 +39,14 @@ decision.
Reporting an issue or making a feature request is a great way to contribute. Your feedback
and the conversations that result from it provide a continuous flow of ideas. However,
before creating a ticket, please take the time to [ask and research](#ask-questions) first.
before creating a ticket, please take the time to [discuss and research](#discuss) first.
If you create an issue after a discussion on Stack Overflow, please provide a description
If creating an issue after a discussion on Stack Overflow, please provide a description
in the issue instead of simply referring to Stack Overflow. The issue tracker is an
important place of record for design discussions and should be self-sufficient.
Once you're ready, create an issue on [GitHub](https://github.com/spring-projects/spring-framework/issues).
Many issues are caused by subtle behavior, typos, and unintended configuration.
Creating a [Minimal Reproducible Example](https://stackoverflow.com/help/minimal-reproducible-example)
(starting with https://start.spring.io for example) of the problem helps the team
quickly triage your issue and get to the core of the problem.
Once you're ready, create an issue on
[GitHub](https://github.com/spring-projects/spring-framework/issues).
#### Issue Lifecycle
@@ -66,7 +63,7 @@ follow-up reports will need to be created as new issues with a fresh description
#### Submit a Pull Request
1. If you have not previously done so, please sign the
[Contributor License Agreement](https://cla.spring.io/sign/spring). You will be reminded
[Contributor License Agreement](https://cla.pivotal.io/sign/spring). You will be reminded
automatically when you submit the PR.
1. Should you create an issue first? No, just create the pull request and use the
@@ -123,13 +120,12 @@ define the source file coding standards we use along with some IDEA editor setti
### Reference Docs
The reference documentation is authored in [Asciidoctor](https://asciidoctor.org/) format
using [Antora](https://docs.antora.org/antora/latest/). The source files for the documentation
reside in the [framework-docs/modules/ROOT](framework-docs/modules/ROOT) directory. For
trivial changes, you may be able to browse, edit source files, and submit directly from GitHub.
The reference documentation is in the [src/docs/asciidoc](src/docs/asciidoc) directory, in
[Asciidoctor](https://asciidoctor.org/) format. For trivial changes, you may be able to browse,
edit source files, and submit directly from GitHub.
When making changes locally, execute `./gradlew antora` and then browse the results under
`framework-docs/build/site/index.html`.
When making changes locally, execute `./gradlew asciidoctor` and then browse the result under
`build/docs/ref-docs/html5/index.html`.
Asciidoctor also supports live editing. For more details see
[AsciiDoc Tooling](https://docs.asciidoctor.org/asciidoctor/latest/tooling/).
+6 -6
View File
@@ -1,8 +1,8 @@
# <img src="framework-docs/src/docs/spring-framework.png" width="80" height="80"> Spring Framework [![Build Status](https://ci.spring.io/api/v1/teams/spring-framework/pipelines/spring-framework-6.1.x/jobs/build/badge)](https://ci.spring.io/teams/spring-framework/pipelines/spring-framework-6.1.x?groups=Build") [![Revved up by Gradle Enterprise](https://img.shields.io/badge/Revved%20up%20by-Gradle%20Enterprise-06A0CE?logo=Gradle&labelColor=02303A)](https://ge.spring.io/scans?search.rootProjectNames=spring)
# <img src="src/docs/spring-framework.png" width="80" height="80"> Spring Framework [![Build Status](https://ci.spring.io/api/v1/teams/spring-framework/pipelines/spring-framework-5.3.x/jobs/build/badge)](https://ci.spring.io/teams/spring-framework/pipelines/spring-framework-5.3.x?groups=Build") [![Revved up by Gradle Enterprise](https://img.shields.io/badge/Revved%20up%20by-Gradle%20Enterprise-06A0CE?logo=Gradle&labelColor=02303A)](https://ge.spring.io/scans?search.rootProjectNames=spring)
This is the home of the Spring Framework: the foundation for all [Spring projects](https://spring.io/projects). Collectively the Spring Framework and the family of Spring projects are often referred to simply as "Spring".
Spring provides everything required beyond the Java programming language for creating enterprise applications for a wide range of scenarios and architectures. Please read the [Overview](https://docs.spring.io/spring-framework/reference/overview.html) section of the reference documentation for a more complete introduction.
Spring provides everything required beyond the Java programming language for creating enterprise applications for a wide range of scenarios and architectures. Please read the [Overview](https://docs.spring.io/spring/docs/current/spring-framework-reference/overview.html#spring-introduction) section as reference for a more complete introduction.
## Code of Conduct
@@ -14,16 +14,16 @@ For access to artifacts or a distribution zip, see the [Spring Framework Artifac
## Documentation
The Spring Framework maintains reference documentation ([published](https://docs.spring.io/spring-framework/reference/) and [source](framework-docs/modules/ROOT)), GitHub [wiki pages](https://github.com/spring-projects/spring-framework/wiki), and an
The Spring Framework maintains reference documentation ([published](https://docs.spring.io/spring-framework/docs/current/spring-framework-reference/) and [source](src/docs/asciidoc)), Github [wiki pages](https://github.com/spring-projects/spring-framework/wiki), and an
[API reference](https://docs.spring.io/spring-framework/docs/current/javadoc-api/). There are also [guides and tutorials](https://spring.io/guides) across Spring projects.
## Micro-Benchmarks
See the [Micro-Benchmarks](https://github.com/spring-projects/spring-framework/wiki/Micro-Benchmarks) wiki page.
See the [Micro-Benchmarks](https://github.com/spring-projects/spring-framework/wiki/Micro-Benchmarks) Wiki page.
## Build from Source
See the [Build from Source](https://github.com/spring-projects/spring-framework/wiki/Build-from-Source) wiki page and the [CONTRIBUTING.md](CONTRIBUTING.md) file.
See the [Build from Source](https://github.com/spring-projects/spring-framework/wiki/Build-from-Source) Wiki page and the [CONTRIBUTING.md](CONTRIBUTING.md) file.
## Continuous Integration Builds
@@ -31,7 +31,7 @@ Information regarding CI builds can be found in the [Spring Framework Concourse
## Stay in Touch
Follow [@SpringCentral](https://twitter.com/springcentral), [@SpringFramework](https://twitter.com/springframework), and its [team members](https://twitter.com/springframework/lists/team/members) on Twitter. In-depth articles can be found at [The Spring Blog](https://spring.io/blog/), and releases are announced via our [releases feed](https://spring.io/blog/category/releases).
Follow [@SpringCentral](https://twitter.com/springcentral), [@SpringFramework](https://twitter.com/springframework), and its [team members](https://twitter.com/springframework/lists/team/members) on Twitter. In-depth articles can be found at [The Spring Blog](https://spring.io/blog/), and releases are announced via our [news feed](https://spring.io/blog/category/news).
## License
-5
View File
@@ -1,10 +1,5 @@
# Security Policy
## JAR signing
Spring Framework JARs released on Maven Central are signed.
You'll find more information about the key here: https://spring.io/GPG-KEY-spring.txt
## Supported Versions
Please see the
+381 -63
View File
@@ -1,40 +1,297 @@
plugins {
id 'io.freefair.aspectj' version '8.4' apply false
// kotlinVersion is managed in gradle.properties
id 'org.jetbrains.kotlin.plugin.serialization' version "${kotlinVersion}" apply false
id 'org.jetbrains.dokka' version '1.8.20'
id 'org.unbroken-dome.xjc' version '2.0.0' apply false
id 'com.github.ben-manes.versions' version '0.49.0'
id 'com.github.johnrengelman.shadow' version '8.1.1' apply false
id 'de.undercouch.download' version '5.4.0'
id 'me.champeau.jmh' version '0.7.2' apply false
id 'me.champeau.mrjar' version '0.1.1'
id 'io.spring.dependency-management' version '1.0.11.RELEASE' apply false
id 'io.spring.nohttp' version '0.0.10'
id "io.freefair.aspectj" version '6.2.0' apply false
id 'org.jetbrains.dokka' version '1.6.10' apply false
id 'org.jetbrains.kotlin.jvm' version '1.5.32' apply false
id "org.jetbrains.kotlin.plugin.serialization" version "1.5.32" apply false
id 'org.asciidoctor.jvm.convert' version '3.3.2'
id 'org.asciidoctor.jvm.pdf' version '3.3.2'
id "org.unbroken-dome.xjc" version '2.0.0' apply false
id "com.github.ben-manes.versions" version '0.39.0'
id "com.github.johnrengelman.shadow" version '7.0.0' apply false
id 'de.undercouch.download' version '4.1.2'
id "me.champeau.jmh" version "0.6.6" apply false
}
ext {
moduleProjects = subprojects.findAll { it.name.startsWith("spring-") }
javaProjects = subprojects.findAll { !it.name.startsWith("framework-") }
javaProjects = subprojects - project(":framework-bom")
withoutJclOverSlf4j = {
exclude group: "org.slf4j", name: "jcl-over-slf4j"
}
}
description = "Spring Framework"
configure(allprojects) { project ->
apply plugin: "org.springframework.build.localdev"
group = "org.springframework"
repositories {
mavenCentral()
maven {
url "https://repo.spring.io/milestone"
content {
// Netty 5 optional support
includeGroup 'io.projectreactor.netty'
apply plugin: "io.spring.dependency-management"
dependencyManagement {
imports {
mavenBom "com.fasterxml.jackson:jackson-bom:2.12.6"
mavenBom "io.netty:netty-bom:4.1.74.Final"
mavenBom "io.projectreactor:reactor-bom:2020.0.16"
mavenBom "io.r2dbc:r2dbc-bom:Arabba-SR12"
mavenBom "io.rsocket:rsocket-bom:1.1.1"
mavenBom "org.eclipse.jetty:jetty-bom:9.4.45.v20220203"
mavenBom "org.jetbrains.kotlin:kotlin-bom:1.5.32"
mavenBom "org.jetbrains.kotlinx:kotlinx-coroutines-bom:1.5.2"
mavenBom "org.jetbrains.kotlinx:kotlinx-serialization-bom:1.2.2"
mavenBom "org.junit:junit-bom:5.8.2"
}
dependencies {
dependencySet(group: 'org.apache.logging.log4j', version: '2.17.1') {
entry 'log4j-api'
entry 'log4j-core'
entry 'log4j-jul'
entry 'log4j-slf4j-impl'
}
dependency "org.slf4j:slf4j-api:1.7.35"
dependency("com.google.code.findbugs:findbugs:3.0.1") {
exclude group: "dom4j", name: "dom4j"
}
dependency "com.google.code.findbugs:jsr305:3.0.2"
dependencySet(group: 'org.aspectj', version: '1.9.7') {
entry 'aspectjrt'
entry 'aspectjtools'
entry 'aspectjweaver'
}
dependencySet(group: 'org.codehaus.groovy', version: '3.0.9') {
entry 'groovy'
entry 'groovy-jsr223'
entry 'groovy-templates' // requires findbugs for warning-free compilation
entry 'groovy-test'
entry 'groovy-xml'
}
dependency "io.reactivex:rxjava:1.3.8"
dependency "io.reactivex:rxjava-reactive-streams:1.2.1"
dependency "io.reactivex.rxjava2:rxjava:2.2.21"
dependency "io.reactivex.rxjava3:rxjava:3.1.3"
dependency "io.smallrye.reactive:mutiny:1.3.1"
dependency "io.projectreactor.tools:blockhound:1.0.6.RELEASE"
dependency "com.caucho:hessian:4.0.63"
dependency "com.fasterxml:aalto-xml:1.3.1"
dependency("com.fasterxml.woodstox:woodstox-core:6.2.8") {
exclude group: "stax", name: "stax-api"
}
dependency "com.google.code.gson:gson:2.8.9"
dependency "com.google.protobuf:protobuf-java-util:3.19.3"
dependency "com.googlecode.protobuf-java-format:protobuf-java-format:1.4"
dependency("com.thoughtworks.xstream:xstream:1.4.18") {
exclude group: "xpp3", name: "xpp3_min"
exclude group: "xmlpull", name: "xmlpull"
}
dependency "org.apache.johnzon:johnzon-jsonb:1.2.16"
dependency("org.codehaus.jettison:jettison:1.3.8") {
exclude group: "stax", name: "stax-api"
}
dependencySet(group: 'org.jibx', version: '1.3.3') {
entry 'jibx-bind'
entry 'jibx-run'
}
dependency "org.ogce:xpp3:1.1.6"
dependency "org.yaml:snakeyaml:1.30"
dependency "com.h2database:h2:2.1.210"
dependency "com.github.ben-manes.caffeine:caffeine:2.9.3"
dependency "com.github.librepdf:openpdf:1.3.26"
dependency "com.rometools:rome:1.18.0"
dependency "commons-io:commons-io:2.5"
dependency "io.vavr:vavr:0.10.4"
dependency "net.sf.jopt-simple:jopt-simple:5.0.4"
dependencySet(group: 'org.apache.activemq', version: '5.16.2') {
entry 'activemq-broker'
entry('activemq-kahadb-store') {
exclude group: "org.springframework", name: "spring-context"
}
entry 'activemq-stomp'
}
dependency "org.apache.bcel:bcel:6.0"
dependency "org.apache.commons:commons-pool2:2.9.0"
dependencySet(group: 'org.apache.derby', version: '10.14.2.0') {
entry 'derby'
entry 'derbyclient'
}
dependency "org.apache.poi:poi-ooxml:4.1.2"
dependency "org.apache-extras.beanshell:bsh:2.0b6"
dependency "org.freemarker:freemarker:2.3.31"
dependency "org.hsqldb:hsqldb:2.5.2"
dependency "org.quartz-scheduler:quartz:2.3.2"
dependency "org.codehaus.fabric3.api:commonj:1.1.0"
dependency "net.sf.ehcache:ehcache:2.10.6"
dependency "org.ehcache:jcache:1.0.1"
dependency "org.ehcache:ehcache:3.4.0"
dependency "org.hibernate:hibernate-core:5.4.33.Final"
dependency "org.hibernate:hibernate-validator:6.2.2.Final"
dependency "org.webjars:webjars-locator-core:0.48"
dependency "org.webjars:underscorejs:1.8.3"
dependencySet(group: 'org.apache.tomcat', version: '9.0.58') {
entry 'tomcat-util'
entry('tomcat-websocket') {
exclude group: "org.apache.tomcat", name: "tomcat-servlet-api"
exclude group: "org.apache.tomcat", name: "tomcat-websocket-api"
}
}
dependencySet(group: 'org.apache.tomcat.embed', version: '9.0.58') {
entry 'tomcat-embed-core'
entry 'tomcat-embed-websocket'
}
dependencySet(group: 'io.undertow', version: '2.2.16.Final') {
entry 'undertow-core'
entry('undertow-servlet') {
exclude group: "org.jboss.spec.javax.servlet", name: "jboss-servlet-api_4.0_spec"
exclude group: "org.jboss.spec.javax.annotation", name: "jboss-annotations-api_1.3_spec"
}
entry('undertow-websockets-jsr') {
exclude group: "org.jboss.spec.javax.websocket", name: "jboss-websocket-api_1.1_spec"
}
}
dependency "org.eclipse.jetty:jetty-reactive-httpclient:1.1.10"
dependency 'org.apache.httpcomponents.client5:httpclient5:5.1.3'
dependency 'org.apache.httpcomponents.core5:httpcore5-reactive:5.1.3'
dependency("org.apache.httpcomponents:httpclient:4.5.13") {
exclude group: "commons-logging", name: "commons-logging"
}
dependency("org.apache.httpcomponents:httpasyncclient:4.1.5") {
exclude group: "commons-logging", name: "commons-logging"
}
dependencySet(group: 'com.squareup.okhttp3', version: '3.14.9') {
entry 'okhttp'
entry 'mockwebserver'
}
dependency "org.jruby:jruby:9.2.20.1"
dependency "org.python:jython-standalone:2.7.1"
dependency "org.mozilla:rhino:1.7.11"
dependency "commons-fileupload:commons-fileupload:1.4"
dependency "org.synchronoss.cloud:nio-multipart-parser:1.1.0"
dependency("org.dom4j:dom4j:2.1.3") {
exclude group: "jaxen", name: "jaxen"
exclude group: "net.java.dev.msv", name: "xsdlib"
exclude group: "pull-parser", name: "pull-parser"
exclude group: "xpp3", name: "xpp3"
}
dependency("jaxen:jaxen:1.2.0") {
exclude group: "dom4j", name: "dom4j"
}
dependency("junit:junit:4.13.2") {
exclude group: "org.hamcrest", name: "hamcrest-core"
}
dependency("de.bechte.junit:junit-hierarchicalcontextrunner:4.12.1") {
exclude group: "junit", name: "junit"
}
dependency "org.testng:testng:7.4.0"
dependency "org.junit.support:testng-engine:1.0.1"
dependency "org.hamcrest:hamcrest:2.1"
dependency "org.awaitility:awaitility:3.1.6"
dependency "org.assertj:assertj-core:3.22.0"
dependencySet(group: 'org.xmlunit', version: '2.9.0') {
entry 'xmlunit-assertj'
entry('xmlunit-matchers') {
exclude group: "org.hamcrest", name: "hamcrest-core"
}
}
dependencySet(group: 'org.mockito', version: '4.3.1') {
entry('mockito-core') {
exclude group: "org.hamcrest", name: "hamcrest-core"
}
entry 'mockito-junit-jupiter'
}
dependency "io.mockk:mockk:1.12.1"
dependency("net.sourceforge.htmlunit:htmlunit:2.58.0") {
exclude group: "commons-logging", name: "commons-logging"
}
dependency("org.seleniumhq.selenium:htmlunit-driver:2.58.0") {
exclude group: "commons-logging", name: "commons-logging"
}
dependency("org.seleniumhq.selenium:selenium-java:3.141.59") {
exclude group: "commons-logging", name: "commons-logging"
exclude group: "io.netty", name: "netty"
}
dependency "org.skyscreamer:jsonassert:1.5.0"
dependency "com.jayway.jsonpath:json-path:2.6.0"
dependency "org.bouncycastle:bcpkix-jdk15on:1.66"
dependencySet(group: 'org.apache.tiles', version: '3.0.8') {
entry 'tiles-api'
entry('tiles-core', withoutJclOverSlf4j)
entry('tiles-servlet', withoutJclOverSlf4j)
entry('tiles-jsp', withoutJclOverSlf4j)
entry('tiles-el', withoutJclOverSlf4j)
entry('tiles-extras') {
exclude group: "org.springframework", name: "spring-web"
exclude group: "org.slf4j", name: "jcl-over-slf4j"
}
}
dependency("org.apache.taglibs:taglibs-standard-jstlel:1.2.5") {
exclude group: "org.apache.taglibs", name: "taglibs-standard-spec"
}
dependency "com.ibm.websphere:uow:6.0.2.17"
dependency "com.jamonapi:jamon:2.82"
dependency "joda-time:joda-time:2.10.13"
dependency "org.eclipse.persistence:org.eclipse.persistence.jpa:2.7.10"
dependency "org.javamoney:moneta:1.3"
dependency "com.sun.activation:javax.activation:1.2.0"
dependency "com.sun.mail:javax.mail:1.6.2"
dependencySet(group: 'com.sun.xml.bind', version: '2.3.0.1') {
entry 'jaxb-core'
entry 'jaxb-impl'
entry 'jaxb-xjc'
}
dependency "javax.activation:javax.activation-api:1.2.0"
dependency "javax.annotation:javax.annotation-api:1.3.2"
dependency "javax.cache:cache-api:1.1.0"
dependency "javax.ejb:javax.ejb-api:3.2"
dependency "javax.el:javax.el-api:3.0.1-b04"
dependency "javax.enterprise.concurrent:javax.enterprise.concurrent-api:1.0"
dependency "javax.faces:javax.faces-api:2.2"
dependency "javax.inject:javax.inject:1"
dependency "javax.inject:javax.inject-tck:1"
dependency "javax.interceptor:javax.interceptor-api:1.2.2"
dependency "javax.jms:javax.jms-api:2.0.1"
dependency "javax.json:javax.json-api:1.1.4"
dependency "javax.json.bind:javax.json.bind-api:1.0"
dependency "javax.mail:javax.mail-api:1.6.2"
dependency "javax.money:money-api:1.0.3"
dependency "javax.resource:javax.resource-api:1.7.1"
dependency "javax.servlet:javax.servlet-api:4.0.1"
dependency "javax.servlet.jsp:javax.servlet.jsp-api:2.3.2-b02"
dependency "javax.servlet.jsp.jstl:javax.servlet.jsp.jstl-api:1.2.1"
dependency "javax.transaction:javax.transaction-api:1.3"
dependency "javax.validation:validation-api:2.0.1.Final"
dependency "javax.websocket:javax.websocket-api:1.1"
dependency "javax.xml.bind:jaxb-api:2.3.1"
dependency "javax.xml.ws:jaxws-api:2.3.1"
dependency "org.eclipse.persistence:javax.persistence:2.2.0"
// Substitute for "javax.management:jmxremote_optional:1.0.1_04" which
// is not available on Maven Central
dependency "org.glassfish.external:opendmk_jmxremote_optional_jar:1.0-b01-ea"
dependency "org.glassfish:javax.el:3.0.1-b08"
dependency "org.glassfish.main:javax.jws:4.0-b33"
dependency "org.glassfish.tyrus:tyrus-container-servlet:1.13.1"
}
if (version.contains('-')) {
maven { url "https://repo.spring.io/milestone" }
generatedPomCustomization {
enabled = false
}
if (version.endsWith('-SNAPSHOT')) {
maven { url "https://repo.spring.io/snapshot" }
resolutionStrategy {
cacheChangingModulesFor 0, "seconds"
}
repositories {
mavenCentral()
maven { url "https://repo.spring.io/libs-spring-framework-build" }
}
}
configurations.all {
@@ -45,27 +302,48 @@ configure(allprojects) { project ->
}
}
configure(allprojects - project(":framework-platform")) {
configurations {
dependencyManagement {
canBeConsumed = false
canBeResolved = false
visible = false
}
matching { it.name.endsWith("Classpath") }.all { it.extendsFrom(dependencyManagement) }
}
dependencies {
dependencyManagement(enforcedPlatform(dependencies.project(path: ":framework-platform")))
}
}
configure([rootProject] + javaProjects) { project ->
group = "org.springframework"
apply plugin: "java"
apply plugin: "java-test-fixtures"
apply plugin: 'org.springframework.build.conventions'
apply plugin: "checkstyle"
apply plugin: 'org.springframework.build.compile'
apply from: "${rootDir}/gradle/toolchains.gradle"
apply from: "${rootDir}/gradle/ide.gradle"
pluginManager.withPlugin("kotlin") {
apply plugin: "org.jetbrains.dokka"
apply from: "${rootDir}/gradle/docs-dokka.gradle"
compileKotlin {
kotlinOptions {
languageVersion = "1.3"
apiVersion = "1.3"
freeCompilerArgs = ["-Xjsr305=strict", "-Xsuppress-version-warnings", "-Xopt-in=kotlin.RequiresOptIn"]
allWarningsAsErrors = true
}
}
compileTestKotlin {
kotlinOptions {
freeCompilerArgs = ["-Xjsr305=strict"]
}
}
}
test {
useJUnitPlatform()
include(["**/*Tests.class", "**/*Test.class"])
systemProperty("java.awt.headless", "true")
systemProperty("testGroups", project.properties.get("testGroups"))
systemProperty("io.netty.leakDetection.level", "paranoid")
}
checkstyle {
toolVersion = "9.3"
configDirectory.set(rootProject.file("src/checkstyle"))
}
dependencies {
testImplementation("org.junit.jupiter:junit-jupiter-api")
testImplementation("org.junit.jupiter:junit-jupiter-params")
@@ -80,41 +358,81 @@ configure([rootProject] + javaProjects) { project ->
testRuntimeOnly("org.junit.platform:junit-platform-suite-engine")
testRuntimeOnly("org.apache.logging.log4j:log4j-core")
testRuntimeOnly("org.apache.logging.log4j:log4j-jul")
testRuntimeOnly("org.apache.logging.log4j:log4j-slf4j2-impl")
testRuntimeOnly("org.apache.logging.log4j:log4j-slf4j-impl")
// JSR-305 only used for non-required meta-annotations
compileOnly("com.google.code.findbugs:jsr305")
testCompileOnly("com.google.code.findbugs:jsr305")
checkstyle("io.spring.javaformat:spring-javaformat-checkstyle:0.0.31")
}
ext.javadocLinks = [
"https://docs.oracle.com/en/java/javase/17/docs/api/",
"https://jakarta.ee/specifications/platform/9/apidocs/",
"https://docs.oracle.com/cd/E13222_01/wls/docs90/javadocs/", // CommonJ and weblogic.* packages
"https://www.ibm.com/docs/api/v1/content/SSEQTP_8.5.5/com.ibm.websphere.javadoc.doc/web/apidocs/", // com.ibm.*
"https://docs.jboss.org/jbossas/javadoc/4.0.5/connector/", // org.jboss.resource.*
"https://docs.jboss.org/hibernate/orm/5.6/javadocs/",
"https://eclipse.dev/aspectj/doc/released/aspectj5rt-api",
"https://docs.oracle.com/javase/8/docs/api/",
"https://docs.oracle.com/javaee/7/api/",
"https://docs.oracle.com/cd/E13222_01/wls/docs90/javadocs/", // CommonJ
"https://www.ibm.com/docs/api/v1/content/SSEQTP_8.5.5/com.ibm.websphere.javadoc.doc/web/apidocs/",
"https://docs.jboss.org/jbossas/javadoc/4.0.5/connector/",
"https://docs.jboss.org/jbossas/javadoc/7.1.2.Final/",
"https://tiles.apache.org/tiles-request/apidocs/",
"https://tiles.apache.org/framework/apidocs/",
"https://www.eclipse.org/aspectj/doc/released/aspectj5rt-api/",
"https://www.ehcache.org/apidocs/2.10.4/",
"https://www.quartz-scheduler.org/api/2.3.0/",
"https://fasterxml.github.io/jackson-core/javadoc/2.14/",
"https://fasterxml.github.io/jackson-databind/javadoc/2.14/",
"https://fasterxml.github.io/jackson-dataformat-xml/javadoc/2.14/",
"https://hc.apache.org/httpcomponents-client-5.2.x/current/httpclient5/apidocs/",
"https://fasterxml.github.io/jackson-core/javadoc/2.10/",
"https://fasterxml.github.io/jackson-databind/javadoc/2.10/",
"https://fasterxml.github.io/jackson-dataformat-xml/javadoc/2.10/",
"https://hc.apache.org/httpcomponents-client-5.1.x/current/httpclient5/apidocs/",
"https://projectreactor.io/docs/test/release/api/",
"https://junit.org/junit4/javadoc/4.13.2/",
// TODO Uncomment link to JUnit 5 docs once we execute Gradle with Java 18+.
// See https://github.com/spring-projects/spring-framework/issues/27497
//
// "https://junit.org/junit5/docs/5.10.1/api/",
// Disabling linking to JUnit 5.8.2, since the `package-list` file no longer exists due to
// https://github.com/junit-team/junit5/commit/67ad4e545518b0ce2b0e7c96df31a669866d5003.
// "https://junit.org/junit5/docs/5.8.2/api/",
"https://www.reactive-streams.org/reactive-streams-1.0.3-javadoc/",
//"https://javadoc.io/static/io.rsocket/rsocket-core/1.1.1/",
"https://r2dbc.io/spec/1.0.0.RELEASE/api/",
// Previously there could be a split-package issue between JSR250 and JSR305 javax.annotation packages,
// but since 6.0 JSR 250 annotations such as @Resource and @PostConstruct have been replaced by their
// JakartaEE equivalents in the jakarta.annotation package.
//"https://www.javadoc.io/doc/com.google.code.findbugs/jsr305/3.0.2/"
"https://javadoc.io/static/io.rsocket/rsocket-core/1.1.1/",
"https://r2dbc.io/spec/0.8.5.RELEASE/api/",
// The external Javadoc link for JSR 305 must come last to ensure that types from
// JSR 250 (such as @PostConstruct) are still supported. This is due to the fact
// that JSR 250 and JSR 305 both define types in javax.annotation, which results
// in a split package, and the javadoc tool does not support split packages
// across multiple external Javadoc sites.
"https://www.javadoc.io/doc/com.google.code.findbugs/jsr305/3.0.2/"
] as String[]
}
configure(moduleProjects) { project ->
apply from: "${rootDir}/gradle/spring-module.gradle"
}
configure(rootProject) {
description = "Spring Framework"
apply plugin: "kotlin"
apply plugin: "io.spring.nohttp"
apply plugin: 'org.springframework.build.api-diff'
apply from: "${rootDir}/gradle/publications.gradle"
apply from: "${rootDir}/gradle/docs.gradle"
nohttp {
source.exclude "**/test-output/**"
allowlistFile = project.file("src/nohttp/allowlist.lines")
def rootPath = file(rootDir).toPath()
def projectDirs = allprojects.collect { it.projectDir } + "${rootDir}/buildSrc"
projectDirs.forEach { dir ->
[ 'bin', 'build', 'out', '.settings' ]
.collect { rootPath.relativize(new File(dir, it).toPath()) }
.forEach { source.exclude "$it/**" }
[ '.classpath', '.project' ]
.collect { rootPath.relativize(new File(dir, it).toPath()) }
.forEach { source.exclude "$it" }
}
}
publishing {
publications {
mavenJava(MavenPublication) {
artifact docsZip
artifact schemaZip
artifact distZip
}
}
}
}
+12 -37
View File
@@ -5,12 +5,9 @@ They are declared in the `build.gradle` file in this folder.
## Build Conventions
The `org.springframework.build.conventions` plugin applies all conventions to the Framework build:
* Configuring the Java compiler, see `JavaConventions`
* Configuring the Kotlin compiler, see `KotlinConventions`
* Configuring testing in the build with `TestConventions`
### Compiler conventions
The `org.springframework.build.compile` plugin applies the Java compiler conventions to the build.
## Build Plugins
@@ -22,39 +19,17 @@ but doesn't affect the classpath of dependent projects.
This plugin does not provide a `provided` configuration, as the native `compileOnly` and `testCompileOnly`
configurations are preferred.
### API Diff
### RuntimeHints Java Agent
This plugin uses the [Gradle JApiCmp](https://github.com/melix/japicmp-gradle-plugin) plugin
to generate API Diff reports for each Spring Framework module. This plugin is applied once on the root
project and creates tasks in each framework module. Unlike previous versions of this part of the build,
there is no need for checking out a specific tag. The plugin will fetch the JARs we want to compare the
current working version with. You can generate the reports for all modules or a single module:
The `spring-core-test` project module contributes the `RuntimeHintsAgent` Java agent.
The `RuntimeHintsAgentPlugin` Gradle plugin creates a dedicated `"runtimeHintsTest"` test task for each project.
This task will detect and execute [tests tagged](https://junit.org/junit5/docs/current/user-guide/#running-tests-build-gradle)
with the `"RuntimeHintsTests"` [JUnit tag](https://junit.org/junit5/docs/current/user-guide/#running-tests-tags).
In the Spring Framework test suite, those are usually annotated with the `@EnabledIfRuntimeHintsAgent` annotation.
By default, the agent will instrument all classes located in the `"org.springframework"` package, as they are loaded.
The `RuntimeHintsAgentExtension` allows to customize this using a DSL:
```groovy
// this applies the `RuntimeHintsAgentPlugin` to the project
plugins {
id 'org.springframework.build.runtimehints-agent'
}
// You can configure the agent to include and exclude packages from the instrumentation process.
runtimeHintsAgent {
includedPackages = ["org.springframework", "io.spring"]
excludedPackages = ["org.example"]
}
dependencies {
// to use the test infrastructure, the project should also depend on the "spring-core-test" module
testImplementation(project(":spring-core-test"))
}
```
./gradlew apiDiff -PbaselineVersion=5.1.0.RELEASE
./gradlew :spring-core:apiDiff -PbaselineVersion=5.1.0.RELEASE
```
With this configuration, `./gradlew runtimeHintsTest` will run all tests instrumented by this java agent.
The global `./gradlew check` task depends on `runtimeHintsTest`.
NOTE: the "spring-core-test" module doesn't shade "spring-core" by design, so the agent should never instrument
code that doesn't have "spring-core" on its classpath.
The reports are located under `build/reports/api-diff/$OLDVERSION_to_$NEWVERSION/`.
+7 -26
View File
@@ -1,6 +1,5 @@
plugins {
id 'java-gradle-plugin'
id 'checkstyle'
}
repositories {
@@ -8,41 +7,23 @@ repositories {
gradlePluginPortal()
}
ext {
def propertiesFile = new File(new File("$projectDir").parentFile, "gradle.properties")
propertiesFile.withInputStream {
def properties = new Properties()
properties.load(it)
set("kotlinVersion", properties["kotlinVersion"])
}
}
dependencies {
checkstyle "io.spring.javaformat:spring-javaformat-checkstyle:${javaFormatVersion}"
implementation "org.jetbrains.kotlin:kotlin-gradle-plugin:${kotlinVersion}"
implementation "org.jetbrains.kotlin:kotlin-compiler-embeddable:${kotlinVersion}"
implementation "org.gradle:test-retry-gradle-plugin:1.5.6"
implementation "io.spring.javaformat:spring-javaformat-gradle-plugin:${javaFormatVersion}"
implementation "io.spring.nohttp:nohttp-gradle:0.0.11"
implementation "me.champeau.gradle:japicmp-gradle-plugin:0.3.0"
}
gradlePlugin {
plugins {
conventionsPlugin {
id = "org.springframework.build.conventions"
implementationClass = "org.springframework.build.ConventionsPlugin"
apiDiffPlugin {
id = "org.springframework.build.api-diff"
implementationClass = "org.springframework.build.api.ApiDiffPlugin"
}
localDevPlugin {
id = "org.springframework.build.localdev"
implementationClass = "org.springframework.build.dev.LocalDevelopmentPlugin"
compileConventionsPlugin {
id = "org.springframework.build.compile"
implementationClass = "org.springframework.build.compile.CompilerConventionsPlugin"
}
optionalDependenciesPlugin {
id = "org.springframework.build.optional-dependencies"
implementationClass = "org.springframework.build.optional.OptionalDependenciesPlugin"
}
runtimeHintsAgentPlugin {
id = "org.springframework.build.runtimehints-agent"
implementationClass = "org.springframework.build.hint.RuntimeHintsAgentPlugin"
}
}
}
-27
View File
@@ -1,27 +0,0 @@
<?xml version="1.0"?>
<!DOCTYPE module PUBLIC "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN" "https://checkstyle.org/dtds/configuration_1_3.dtd">
<module name="com.puppycrawl.tools.checkstyle.Checker">
<!-- Root Checks -->
<module name="io.spring.javaformat.checkstyle.check.SpringHeaderCheck">
<property name="fileExtensions" value="java"/>
<property name="headerType" value="apache2"/>
<property name="headerCopyrightPattern" value="20\d\d-20\d\d"/>
<property name="packageInfoHeaderType" value="none"/>
</module>
<module name="com.puppycrawl.tools.checkstyle.checks.NewlineAtEndOfFileCheck"/>
<!-- TreeWalker Checks -->
<module name="com.puppycrawl.tools.checkstyle.TreeWalker">
<!-- Imports -->
<module name="com.puppycrawl.tools.checkstyle.checks.imports.UnusedImportsCheck">
<property name="processJavadoc" value="true"/>
</module>
<!-- Modifiers -->
<module name="com.puppycrawl.tools.checkstyle.checks.modifier.ModifierOrderCheck"/>
</module>
</module>
-1
View File
@@ -1,2 +1 @@
org.gradle.caching=true
javaFormatVersion=0.0.39
@@ -1,79 +0,0 @@
/*
* Copyright 2002-2023 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.build;
import java.io.File;
import java.nio.file.Path;
import java.util.List;
import io.spring.javaformat.gradle.SpringJavaFormatPlugin;
import io.spring.nohttp.gradle.NoHttpExtension;
import io.spring.nohttp.gradle.NoHttpPlugin;
import org.gradle.api.Plugin;
import org.gradle.api.Project;
import org.gradle.api.artifacts.DependencySet;
import org.gradle.api.plugins.JavaBasePlugin;
import org.gradle.api.plugins.quality.Checkstyle;
import org.gradle.api.plugins.quality.CheckstyleExtension;
import org.gradle.api.plugins.quality.CheckstylePlugin;
/**
* {@link Plugin} that applies conventions for checkstyle.
*
* @author Brian Clozel
*/
public class CheckstyleConventions {
/**
* Applies the Spring Java Format and Checkstyle plugins with the project conventions.
* @param project the current project
*/
public void apply(Project project) {
project.getPlugins().withType(JavaBasePlugin.class, (java) -> {
if (project.getRootProject() == project) {
configureNoHttpPlugin(project);
}
project.getPlugins().apply(CheckstylePlugin.class);
project.getTasks().withType(Checkstyle.class).forEach(checkstyle -> checkstyle.getMaxHeapSize().set("1g"));
CheckstyleExtension checkstyle = project.getExtensions().getByType(CheckstyleExtension.class);
checkstyle.setToolVersion("10.12.5");
checkstyle.getConfigDirectory().set(project.getRootProject().file("src/checkstyle"));
String version = SpringJavaFormatPlugin.class.getPackage().getImplementationVersion();
DependencySet checkstyleDependencies = project.getConfigurations().getByName("checkstyle").getDependencies();
checkstyleDependencies
.add(project.getDependencies().create("io.spring.javaformat:spring-javaformat-checkstyle:" + version));
});
}
private static void configureNoHttpPlugin(Project project) {
project.getPlugins().apply(NoHttpPlugin.class);
NoHttpExtension noHttp = project.getExtensions().getByType(NoHttpExtension.class);
noHttp.setAllowlistFile(project.file("src/nohttp/allowlist.lines"));
noHttp.getSource().exclude("**/test-output/**", "**/.settings/**",
"**/.classpath", "**/.project", "**/.gradle/**");
List<String> buildFolders = List.of("bin", "build", "out");
project.allprojects(subproject -> {
Path rootPath = project.getRootDir().toPath();
Path projectPath = rootPath.relativize(subproject.getProjectDir().toPath());
for (String buildFolder : buildFolders) {
Path innerBuildDir = projectPath.resolve(buildFolder);
noHttp.getSource().exclude(innerBuildDir + File.separator + "**");
}
});
}
}
@@ -1,45 +0,0 @@
/*
* Copyright 2002-2023 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.build;
import org.gradle.api.Plugin;
import org.gradle.api.Project;
import org.gradle.api.plugins.JavaBasePlugin;
import org.jetbrains.kotlin.gradle.plugin.KotlinBasePlugin;
/**
* Plugin to apply conventions to projects that are part of Spring Framework's build.
* Conventions are applied in response to various plugins being applied.
*
* <p>When the {@link JavaBasePlugin} is applied, the conventions in {@link CheckstyleConventions},
* {@link TestConventions} and {@link JavaConventions} are applied.
* When the {@link KotlinBasePlugin} is applied, the conventions in {@link KotlinConventions}
* are applied.
*
* @author Brian Clozel
*/
public class ConventionsPlugin implements Plugin<Project> {
@Override
public void apply(Project project) {
new CheckstyleConventions().apply(project);
new JavaConventions().apply(project);
new KotlinConventions().apply(project);
new TestConventions().apply(project);
}
}
@@ -1,48 +0,0 @@
/*
* Copyright 2002-2022 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.build;
import java.util.ArrayList;
import java.util.List;
import org.gradle.api.Project;
import org.jetbrains.kotlin.gradle.dsl.KotlinJvmOptions;
import org.jetbrains.kotlin.gradle.tasks.KotlinCompile;
/**
* @author Brian Clozel
*/
public class KotlinConventions {
void apply(Project project) {
project.getPlugins().withId("org.jetbrains.kotlin.jvm",
(plugin) -> project.getTasks().withType(KotlinCompile.class, this::configure));
}
private void configure(KotlinCompile compile) {
KotlinJvmOptions kotlinOptions = compile.getKotlinOptions();
kotlinOptions.setApiVersion("1.7");
kotlinOptions.setLanguageVersion("1.7");
kotlinOptions.setJvmTarget("17");
kotlinOptions.setJavaParameters(true);
kotlinOptions.setAllWarningsAsErrors(true);
List<String> freeCompilerArgs = new ArrayList<>(compile.getKotlinOptions().getFreeCompilerArgs());
freeCompilerArgs.addAll(List.of("-Xsuppress-version-warnings", "-Xjsr305=strict", "-opt-in=kotlin.RequiresOptIn"));
compile.getKotlinOptions().setFreeCompilerArgs(freeCompilerArgs);
}
}
@@ -1,82 +0,0 @@
/*
* Copyright 2002-2023 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.build;
import java.util.Map;
import org.gradle.api.Project;
import org.gradle.api.plugins.JavaBasePlugin;
import org.gradle.api.tasks.testing.Test;
import org.gradle.testretry.TestRetryPlugin;
import org.gradle.testretry.TestRetryTaskExtension;
/**
* Conventions that are applied in the presence of the {@link JavaBasePlugin}. When the
* plugin is applied:
* <ul>
* <li>The {@link TestRetryPlugin Test Retry} plugin is applied so that flaky tests
* are retried 3 times when running on the CI server.
* </ul>
*
* @author Brian Clozel
* @author Andy Wilkinson
*/
class TestConventions {
void apply(Project project) {
project.getPlugins().withType(JavaBasePlugin.class, (java) -> configureTestConventions(project));
}
private void configureTestConventions(Project project) {
project.getTasks().withType(Test.class,
test -> {
configureTests(project, test);
configureTestRetryPlugin(project, test);
});
}
private void configureTests(Project project, Test test) {
test.useJUnitPlatform();
test.include("**/*Tests.class", "**/*Test.class");
test.setSystemProperties(Map.of(
"java.awt.headless", "true",
"io.netty.leakDetection.level", "paranoid",
"io.netty5.leakDetectionLevel", "paranoid",
"io.netty5.leakDetection.targetRecords", "32",
"io.netty5.buffer.lifecycleTracingEnabled", "true"
));
if (project.hasProperty("testGroups")) {
test.systemProperty("testGroups", project.getProperties().get("testGroups"));
}
test.jvmArgs("--add-opens=java.base/java.lang=ALL-UNNAMED",
"--add-opens=java.base/java.util=ALL-UNNAMED",
"-Djava.locale.providers=COMPAT");
}
private void configureTestRetryPlugin(Project project, Test test) {
project.getPlugins().withType(TestRetryPlugin.class, testRetryPlugin -> {
TestRetryTaskExtension testRetry = test.getExtensions().getByType(TestRetryTaskExtension.class);
testRetry.getFailOnPassedAfterRetry().set(true);
testRetry.getMaxRetries().set(isCi() ? 3 : 0);
});
}
private boolean isCi() {
return Boolean.parseBoolean(System.getenv("CI"));
}
}
@@ -0,0 +1,115 @@
/*
* Copyright 2002-2019 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.build.api;
import java.io.File;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Collections;
import java.util.List;
import me.champeau.gradle.japicmp.JapicmpPlugin;
import me.champeau.gradle.japicmp.JapicmpTask;
import org.gradle.api.Plugin;
import org.gradle.api.Project;
import org.gradle.api.artifacts.Configuration;
import org.gradle.api.artifacts.Dependency;
import org.gradle.api.plugins.JavaBasePlugin;
import org.gradle.api.plugins.JavaPlugin;
import org.gradle.api.publish.maven.plugins.MavenPublishPlugin;
import org.gradle.api.tasks.TaskProvider;
import org.gradle.jvm.tasks.Jar;
/**
* {@link Plugin} that applies the {@code "japicmp-gradle-plugin"}
* and create tasks for all subprojects, diffing the public API one by one
* and creating the reports in {@code "build/reports/api-diff/$OLDVERSION_to_$NEWVERSION/"}.
* <p>{@code "./gradlew apiDiff -PbaselineVersion=5.1.0.RELEASE"} will output the
* reports for the API diff between the baseline version and the current one for all modules.
* You can limit the report to a single module with
* {@code "./gradlew :spring-core:apiDiff -PbaselineVersion=5.1.0.RELEASE"}.
*
* @author Brian Clozel
*/
public class ApiDiffPlugin implements Plugin<Project> {
public static final String TASK_NAME = "apiDiff";
private static final String BASELINE_VERSION_PROPERTY = "baselineVersion";
private static final List<String> PACKAGE_INCLUDES = Collections.singletonList("org.springframework.*");
@Override
public void apply(Project project) {
if (project.hasProperty(BASELINE_VERSION_PROPERTY) && project.equals(project.getRootProject())) {
project.getPluginManager().apply(JapicmpPlugin.class);
project.getPlugins().withType(JapicmpPlugin.class,
plugin -> applyApiDiffConventions(project));
}
}
private void applyApiDiffConventions(Project project) {
String baselineVersion = project.property(BASELINE_VERSION_PROPERTY).toString();
project.subprojects(subProject -> createApiDiffTask(baselineVersion, subProject));
}
private void createApiDiffTask(String baselineVersion, Project project) {
if (isProjectEligible(project)) {
JapicmpTask apiDiff = project.getTasks().create(TASK_NAME, JapicmpTask.class);
apiDiff.setDescription("Generates an API diff report with japicmp");
apiDiff.setGroup(JavaBasePlugin.DOCUMENTATION_GROUP);
apiDiff.setOldClasspath(project.files(createBaselineConfiguration(baselineVersion, project)));
TaskProvider<Jar> jar = project.getTasks().withType(Jar.class).named("jar");
apiDiff.setNewArchives(project.getLayout().files(jar.get().getArchiveFile().get().getAsFile()));
apiDiff.setNewClasspath(getRuntimeClassPath(project));
apiDiff.setPackageIncludes(PACKAGE_INCLUDES);
apiDiff.setOnlyModified(true);
apiDiff.setIgnoreMissingClasses(true);
// Ignore Kotlin metadata annotations since they contain
// illegal HTML characters and fail the report generation
apiDiff.setAnnotationExcludes(Collections.singletonList("@kotlin.Metadata"));
apiDiff.setHtmlOutputFile(getOutputFile(baselineVersion, project));
apiDiff.dependsOn(project.getTasks().getByName("jar"));
}
}
private boolean isProjectEligible(Project project) {
return project.getPlugins().hasPlugin(JavaPlugin.class)
&& project.getPlugins().hasPlugin(MavenPublishPlugin.class);
}
private Configuration createBaselineConfiguration(String baselineVersion, Project project) {
String baseline = String.join(":",
project.getGroup().toString(), project.getName(), baselineVersion);
Dependency baselineDependency = project.getDependencies().create(baseline + "@jar");
return project.getRootProject().getConfigurations().detachedConfiguration(baselineDependency);
}
private Configuration getRuntimeClassPath(Project project) {
return project.getConfigurations().getByName(JavaPlugin.RUNTIME_CLASSPATH_CONFIGURATION_NAME);
}
private File getOutputFile(String baseLineVersion, Project project) {
Path outDir = Paths.get(project.getRootProject().getBuildDir().getAbsolutePath(),
"reports", "api-diff",
baseLineVersion + "_to_" + project.getRootProject().getVersion());
return project.file(outDir.resolve(project.getName() + ".html").toString());
}
}
@@ -1,5 +1,5 @@
/*
* Copyright 2002-2023 the original author or authors.
* Copyright 2002-2021 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
@@ -14,7 +14,7 @@
* limitations under the License.
*/
package org.springframework.build;
package org.springframework.build.compile;
import java.util.ArrayList;
import java.util.Arrays;
@@ -22,12 +22,10 @@ import java.util.List;
import org.gradle.api.Plugin;
import org.gradle.api.Project;
import org.gradle.api.plugins.JavaBasePlugin;
import org.gradle.api.plugins.JavaLibraryPlugin;
import org.gradle.api.plugins.JavaPlugin;
import org.gradle.api.plugins.JavaPluginExtension;
import org.gradle.api.plugins.JavaPluginConvention;
import org.gradle.api.tasks.compile.JavaCompile;
import org.gradle.jvm.toolchain.JavaLanguageVersion;
import org.gradle.jvm.toolchain.JvmVendorSpec;
/**
* {@link Plugin} that applies conventions for compiling Java sources in Spring Framework.
@@ -36,7 +34,7 @@ import org.gradle.jvm.toolchain.JvmVendorSpec;
* @author Sam Brannen
* @author Sebastien Deleuze
*/
public class JavaConventions {
public class CompilerConventionsPlugin implements Plugin<Project> {
private static final List<String> COMPILER_ARGS;
@@ -61,8 +59,9 @@ public class JavaConventions {
"-Xlint:-deprecation", "-Xlint:-unchecked"));
}
@Override
public void apply(Project project) {
project.getPlugins().withType(JavaBasePlugin.class, javaPlugin -> applyJavaCompileConventions(project));
project.getPlugins().withType(JavaLibraryPlugin.class, javaPlugin -> applyJavaCompileConventions(project));
}
/**
@@ -71,10 +70,7 @@ public class JavaConventions {
* @param project the current project
*/
private void applyJavaCompileConventions(Project project) {
project.getExtensions().getByType(JavaPluginExtension.class).toolchain(toolchain -> {
toolchain.getVendor().set(JvmVendorSpec.BELLSOFT);
toolchain.getLanguageVersion().set(JavaLanguageVersion.of(17));
});
JavaPluginConvention java = project.getConvention().getPlugin(JavaPluginConvention.class);
project.getTasks().withType(JavaCompile.class)
.matching(compileTask -> compileTask.getName().equals(JavaPlugin.COMPILE_JAVA_TASK_NAME))
.forEach(compileTask -> {
@@ -1,49 +0,0 @@
/*
* Copyright 2002-2023 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.build.dev;
import org.gradle.api.Plugin;
import org.gradle.api.Project;
import org.gradle.api.plugins.JavaBasePlugin;
/**
* {@link Plugin} that skips documentation tasks when the {@code "-PskipDocs"} property is defined.
*
* @author Brian Clozel
*/
public class LocalDevelopmentPlugin implements Plugin<Project> {
private static final String SKIP_DOCS_PROPERTY = "skipDocs";
@Override
public void apply(Project target) {
if (target.hasProperty(SKIP_DOCS_PROPERTY)) {
skipDocumentationTasks(target);
target.subprojects(this::skipDocumentationTasks);
}
}
private void skipDocumentationTasks(Project project) {
project.afterEvaluate(p -> {
p.getTasks().matching(task -> {
return JavaBasePlugin.DOCUMENTATION_GROUP.equals(task.getGroup())
|| "distribution".equals(task.getGroup());
})
.forEach(task -> task.setEnabled(false));
});
}
}
@@ -1,48 +0,0 @@
/*
* Copyright 2002-2023 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.build.hint;
import java.util.Collections;
import org.gradle.api.file.ConfigurableFileCollection;
import org.gradle.api.provider.SetProperty;
import org.gradle.api.tasks.Classpath;
import org.gradle.api.tasks.Input;
import org.gradle.process.CommandLineArgumentProvider;
/**
* Argument provider for registering the runtime hints agent with a Java process.
*/
public interface RuntimeHintsAgentArgumentProvider extends CommandLineArgumentProvider {
@Classpath
ConfigurableFileCollection getAgentJar();
@Input
SetProperty<String> getIncludedPackages();
@Input
SetProperty<String> getExcludedPackages();
@Override
default Iterable<String> asArguments() {
StringBuilder packages = new StringBuilder();
getIncludedPackages().get().forEach(packageName -> packages.append('+').append(packageName).append(','));
getExcludedPackages().get().forEach(packageName -> packages.append('-').append(packageName).append(','));
return Collections.singleton("-javaagent:" + getAgentJar().getSingleFile() + "=" + packages);
}
}
@@ -1,30 +0,0 @@
/*
* Copyright 2002-2023 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.build.hint;
import org.gradle.api.provider.SetProperty;
/**
* Entry point to the DSL extension for the {@link RuntimeHintsAgentPlugin} Gradle plugin.
* @author Brian Clozel
*/
public interface RuntimeHintsAgentExtension {
SetProperty<String> getIncludedPackages();
SetProperty<String> getExcludedPackages();
}
@@ -1,94 +0,0 @@
/*
* Copyright 2002-2023 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.build.hint;
import org.gradle.api.JavaVersion;
import org.gradle.api.Plugin;
import org.gradle.api.Project;
import org.gradle.api.artifacts.Configuration;
import org.gradle.api.attributes.Bundling;
import org.gradle.api.attributes.Category;
import org.gradle.api.attributes.LibraryElements;
import org.gradle.api.attributes.Usage;
import org.gradle.api.attributes.java.TargetJvmVersion;
import org.gradle.api.plugins.JavaPlugin;
import org.gradle.api.tasks.testing.Test;
import java.util.Collections;
/**
* {@link Plugin} that configures the {@code RuntimeHints} Java agent to test tasks.
*
* @author Brian Clozel
* @author Sebastien Deleuze
*/
public class RuntimeHintsAgentPlugin implements Plugin<Project> {
public static final String RUNTIMEHINTS_TEST_TASK = "runtimeHintsTest";
private static final String EXTENSION_NAME = "runtimeHintsAgent";
private static final String CONFIGURATION_NAME = "testRuntimeHintsAgentJar";
@Override
public void apply(Project project) {
project.getPlugins().withType(JavaPlugin.class, javaPlugin -> {
RuntimeHintsAgentExtension agentExtension = createRuntimeHintsAgentExtension(project);
Test agentTest = project.getTasks().create(RUNTIMEHINTS_TEST_TASK, Test.class, test -> {
test.useJUnitPlatform(options -> {
options.includeTags("RuntimeHintsTests");
});
test.include("**/*Tests.class", "**/*Test.class");
test.systemProperty("java.awt.headless", "true");
test.systemProperty("org.graalvm.nativeimage.imagecode", "runtime");
test.getJvmArgumentProviders().add(createRuntimeHintsAgentArgumentProvider(project, agentExtension));
});
project.getTasks().getByName("check", task -> task.dependsOn(agentTest));
project.getDependencies().add(CONFIGURATION_NAME, project.project(":spring-core-test"));
});
}
private static RuntimeHintsAgentExtension createRuntimeHintsAgentExtension(Project project) {
RuntimeHintsAgentExtension agentExtension = project.getExtensions().create(EXTENSION_NAME, RuntimeHintsAgentExtension.class);
agentExtension.getIncludedPackages().convention(Collections.singleton("org.springframework"));
agentExtension.getExcludedPackages().convention(Collections.emptySet());
return agentExtension;
}
private static RuntimeHintsAgentArgumentProvider createRuntimeHintsAgentArgumentProvider(
Project project, RuntimeHintsAgentExtension agentExtension) {
RuntimeHintsAgentArgumentProvider agentArgumentProvider = project.getObjects().newInstance(RuntimeHintsAgentArgumentProvider.class);
agentArgumentProvider.getAgentJar().from(createRuntimeHintsAgentConfiguration(project));
agentArgumentProvider.getIncludedPackages().set(agentExtension.getIncludedPackages());
agentArgumentProvider.getExcludedPackages().set(agentExtension.getExcludedPackages());
return agentArgumentProvider;
}
private static Configuration createRuntimeHintsAgentConfiguration(Project project) {
return project.getConfigurations().create(CONFIGURATION_NAME, configuration -> {
configuration.setCanBeConsumed(false);
configuration.setTransitive(false); // Only the built artifact is required
configuration.attributes(attributes -> {
attributes.attribute(Bundling.BUNDLING_ATTRIBUTE, project.getObjects().named(Bundling.class, Bundling.EXTERNAL));
attributes.attribute(Category.CATEGORY_ATTRIBUTE, project.getObjects().named(Category.class, Category.LIBRARY));
attributes.attribute(LibraryElements.LIBRARY_ELEMENTS_ATTRIBUTE, project.getObjects().named(LibraryElements.class, LibraryElements.JAR));
attributes.attribute(TargetJvmVersion.TARGET_JVM_VERSION_ATTRIBUTE, Integer.valueOf(JavaVersion.current().getMajorVersion()));
attributes.attribute(Usage.USAGE_ATTRIBUTE, project.getObjects().named(Usage.class, Usage.JAVA_RUNTIME));
});
});
}
}
@@ -1,5 +1,5 @@
/*
* Copyright 2002-2023 the original author or authors.
* Copyright 2002-2021 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
@@ -19,9 +19,12 @@ package org.springframework.build.optional;
import org.gradle.api.Plugin;
import org.gradle.api.Project;
import org.gradle.api.artifacts.Configuration;
import org.gradle.api.plugins.JavaBasePlugin;
import org.gradle.api.plugins.JavaPluginExtension;
import org.gradle.api.attributes.Usage;
import org.gradle.api.plugins.JavaPlugin;
import org.gradle.api.plugins.JavaPluginConvention;
import org.gradle.api.tasks.SourceSetContainer;
import org.gradle.plugins.ide.eclipse.EclipsePlugin;
import org.gradle.plugins.ide.eclipse.model.EclipseModel;
/**
* A {@code Plugin} that adds support for Maven-style optional dependencies. Creates a new
@@ -40,11 +43,11 @@ public class OptionalDependenciesPlugin implements Plugin<Project> {
@Override
public void apply(Project project) {
Configuration optional = project.getConfigurations().create(OPTIONAL_CONFIGURATION_NAME);
Configuration optional = project.getConfigurations().create("optional");
optional.setCanBeConsumed(false);
optional.setCanBeResolved(false);
project.getPlugins().withType(JavaBasePlugin.class, (javaBasePlugin) -> {
SourceSetContainer sourceSets = project.getExtensions().getByType(JavaPluginExtension.class)
project.getPlugins().withType(JavaPlugin.class, (javaPlugin) -> {
SourceSetContainer sourceSets = project.getConvention().getPlugin(JavaPluginConvention.class)
.getSourceSets();
sourceSets.all((sourceSet) -> {
project.getConfigurations().getByName(sourceSet.getCompileClasspathConfigurationName()).extendsFrom(optional);
@@ -53,4 +56,4 @@ public class OptionalDependenciesPlugin implements Plugin<Project> {
});
}
}
}
@@ -1,191 +0,0 @@
/*
* Copyright 2002-2023 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.build.shadow;
import java.io.File;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import org.gradle.api.DefaultTask;
import org.gradle.api.artifacts.Configuration;
import org.gradle.api.artifacts.component.ModuleComponentSelector;
import org.gradle.api.artifacts.query.ArtifactResolutionQuery;
import org.gradle.api.artifacts.result.ArtifactResolutionResult;
import org.gradle.api.artifacts.result.ComponentArtifactsResult;
import org.gradle.api.artifacts.result.DependencyResult;
import org.gradle.api.artifacts.result.ResolutionResult;
import org.gradle.api.artifacts.result.ResolvedArtifactResult;
import org.gradle.api.file.DirectoryProperty;
import org.gradle.api.file.FileCopyDetails;
import org.gradle.api.file.FileTree;
import org.gradle.api.tasks.Classpath;
import org.gradle.api.tasks.Input;
import org.gradle.api.tasks.Nested;
import org.gradle.api.tasks.Optional;
import org.gradle.api.tasks.OutputDirectory;
import org.gradle.api.tasks.TaskAction;
import org.gradle.jvm.JvmLibrary;
import org.gradle.language.base.artifact.SourcesArtifact;
/**
* Gradle task to add source from shadowed jars into our own source jars.
*
* @author Phillip Webb
* @author Andy Wilkinson
*/
public class ShadowSource extends DefaultTask {
private final DirectoryProperty outputDirectory = getProject().getObjects().directoryProperty();
private List<Configuration> configurations = new ArrayList<>();
private final List<Relocation> relocations = new ArrayList<>();
@Classpath
@Optional
public List<Configuration> getConfigurations() {
return this.configurations;
}
public void setConfigurations(List<Configuration> configurations) {
this.configurations = configurations;
}
@Nested
public List<Relocation> getRelocations() {
return this.relocations;
}
public void relocate(String pattern, String destination) {
this.relocations.add(new Relocation(pattern, destination));
}
@OutputDirectory
DirectoryProperty getOutputDirectory() {
return this.outputDirectory;
}
@TaskAction
void syncSourceJarFiles() {
sync(getSourceJarFiles());
}
private List<File> getSourceJarFiles() {
List<File> sourceJarFiles = new ArrayList<>();
for (Configuration configuration : this.configurations) {
ResolutionResult resolutionResult = configuration.getIncoming().getResolutionResult();
resolutionResult.getRootComponent().get().getDependencies().forEach(dependency -> {
Set<ComponentArtifactsResult> artifactsResults = resolveSourceArtifacts(dependency);
for (ComponentArtifactsResult artifactResult : artifactsResults) {
artifactResult.getArtifacts(SourcesArtifact.class).forEach(sourceArtifact -> {
sourceJarFiles.add(((ResolvedArtifactResult) sourceArtifact).getFile());
});
}
});
}
return Collections.unmodifiableList(sourceJarFiles);
}
private Set<ComponentArtifactsResult> resolveSourceArtifacts(DependencyResult dependency) {
ModuleComponentSelector componentSelector = (ModuleComponentSelector) dependency.getRequested();
ArtifactResolutionQuery query = getProject().getDependencies().createArtifactResolutionQuery()
.forModule(componentSelector.getGroup(), componentSelector.getModule(), componentSelector.getVersion());
return executeQuery(query).getResolvedComponents();
}
@SuppressWarnings("unchecked")
private ArtifactResolutionResult executeQuery(ArtifactResolutionQuery query) {
return query.withArtifacts(JvmLibrary.class, SourcesArtifact.class).execute();
}
private void sync(List<File> sourceJarFiles) {
getProject().sync(spec -> {
spec.into(this.outputDirectory);
spec.eachFile(this::relocateFile);
spec.filter(this::transformContent);
spec.exclude("META-INF/**");
spec.setIncludeEmptyDirs(false);
sourceJarFiles.forEach(sourceJar -> spec.from(zipTree(sourceJar)));
});
}
private void relocateFile(FileCopyDetails details) {
String path = details.getPath();
for (Relocation relocation : this.relocations) {
path = relocation.relocatePath(path);
}
details.setPath(path);
}
private String transformContent(String content) {
for (Relocation relocation : this.relocations) {
content = relocation.transformContent(content);
}
return content;
}
private FileTree zipTree(File sourceJar) {
return getProject().zipTree(sourceJar);
}
/**
* A single relocation.
*/
static class Relocation {
private final String pattern;
private final String pathPattern;
private final String destination;
private final String pathDestination;
Relocation(String pattern, String destination) {
this.pattern = pattern;
this.pathPattern = pattern.replace('.', '/');
this.destination = destination;
this.pathDestination = destination.replace('.', '/');
}
@Input
public String getPattern() {
return this.pattern;
}
@Input
public String getDestination() {
return this.destination;
}
String relocatePath(String path) {
return path.replace(this.pathPattern, this.pathDestination);
}
public String transformContent(String content) {
return content.replaceAll("\\b" + this.pattern, this.destination);
}
}
}
+2 -2
View File
@@ -2,7 +2,7 @@
The Spring Framework uses https://concourse-ci.org/[Concourse] for its CI build and other automated tasks.
The Spring team has a dedicated Concourse instance available at https://ci.spring.io with a build pipeline
for https://ci.spring.io/teams/spring-framework/pipelines/spring-framework-6.0.x[Spring Framework 6.0.x].
for https://ci.spring.io/teams/spring-framework/pipelines/spring-framework-5.3.x[Spring Framework 5.3.x].
=== Setting up your development environment
@@ -51,7 +51,7 @@ The pipeline can be deployed using the following command:
[source]
----
$ fly -t spring set-pipeline -p spring-framework-6.0.x -c ci/pipeline.yml -l ci/parameters.yml
$ fly -t spring set-pipeline -p spring-framework-5.3.x -c ci/pipeline.yml -l ci/parameters.yml
----
NOTE: This assumes that you have credhub integration configured with the appropriate secrets.
-3
View File
@@ -15,6 +15,3 @@ changelog:
sort: "title"
labels:
- "type: dependency-upgrade"
contributors:
exclude:
names: ["bclozel", "jhoeller", "poutsma", "rstoyanchev", "sbrannen", "sdeleuze", "snicoll", "simonbasle"]
+4 -5
View File
@@ -1,12 +1,11 @@
FROM ubuntu:jammy-20231128
FROM ubuntu:focal-20220113
ADD setup.sh /setup.sh
ADD get-jdk-url.sh /get-jdk-url.sh
RUN ./setup.sh
RUN ./setup.sh java8
ENV JAVA_HOME /opt/openjdk/java17
ENV JAVA_HOME /opt/openjdk/java8
ENV JDK11 /opt/openjdk/java11
ENV JDK17 /opt/openjdk/java17
ENV JDK21 /opt/openjdk/java21
ENV JDK22 /opt/openjdk/java22
ENV PATH $JAVA_HOME/bin:$PATH
+11 -8
View File
@@ -2,16 +2,19 @@
set -e
case "$1" in
java17)
echo "https://download.bell-sw.com/java/17.0.9+11/bellsoft-jdk17.0.9+11-linux-amd64.tar.gz"
java8)
echo "https://github.com/adoptium/temurin8-binaries/releases/download/jdk8u322-b06/OpenJDK8U-jdk_x64_linux_hotspot_8u322b06.tar.gz"
;;
java21)
echo "https://download.bell-sw.com/java/21.0.1+12/bellsoft-jdk21.0.1+12-linux-amd64.tar.gz"
java11)
echo "https://github.com/adoptium/temurin11-binaries/releases/download/jdk-11.0.14.1%2B1/OpenJDK11U-jdk_x64_linux_hotspot_11.0.14.1_1.tar.gz"
;;
java22)
echo "https://download.java.net/java/early_access/jdk22/27/GPL/openjdk-22-ea+27_linux-x64_bin.tar.gz"
;;
*)
java17)
echo "https://github.com/adoptium/temurin17-binaries/releases/download/jdk-17.0.2%2B8/OpenJDK17U-jdk_x64_linux_hotspot_17.0.2_8.tar.gz"
;;
java18)
echo "https://github.com/adoptium/temurin18-binaries/releases/download/jdk18-2022-02-12-08-06-beta/OpenJDK18-jdk_x64_linux_hotspot_2022-02-12-08-06.tar.gz"
;;
*)
echo $"Unknown java version"
exit 1
esac
+3 -1
View File
@@ -14,13 +14,15 @@ rm -rf /var/lib/apt/lists/*
curl https://raw.githubusercontent.com/spring-io/concourse-java-scripts/v0.0.4/concourse-java.sh > /opt/concourse-java.sh
curl --output /opt/concourse-release-scripts.jar https://repo.spring.io/release/io/spring/concourse/releasescripts/concourse-release-scripts/0.3.3/concourse-release-scripts-0.3.3.jar
###########################################################
# JAVA
###########################################################
mkdir -p /opt/openjdk
pushd /opt/openjdk > /dev/null
for jdk in java17 java21 java22
for jdk in java8 java11 java17
do
JDK_URL=$( /get-jdk-url.sh $jdk )
mkdir $jdk
+2 -3
View File
@@ -1,10 +1,9 @@
github-repo: "https://github.com/spring-projects/spring-framework.git"
github-repo-name: "spring-projects/spring-framework"
sonatype-staging-profile: "org.springframework"
docker-hub-organization: "springci"
artifactory-server: "https://repo.spring.io"
branch: "main"
milestone: "6.1.x"
branch: "5.3.x"
milestone: "5.3.x"
build-name: "spring-framework"
pipeline-name: "spring-framework"
concourse-url: "https://ci.spring.io"
+111 -77
View File
@@ -12,7 +12,7 @@ anchors:
SONATYPE_USERNAME: ((sonatype-username))
SONATYPE_PASSWORD: ((sonatype-password))
SONATYPE_URL: ((sonatype-url))
SONATYPE_STAGING_PROFILE: ((sonatype-staging-profile))
SONATYPE_STAGING_PROFILE_ID: ((sonatype-staging-profile-id))
artifactory-task-params: &artifactory-task-params
ARTIFACTORY_SERVER: ((artifactory-server))
ARTIFACTORY_USERNAME: ((artifactory-username))
@@ -23,6 +23,7 @@ anchors:
docker-resource-source: &docker-resource-source
username: ((docker-hub-username))
password: ((docker-hub-password))
tag: ((milestone))
slack-fail-params: &slack-fail-params
text: >
:concourse-failed: <https://ci.spring.io/teams/${BUILD_TEAM_NAME}/pipelines/${BUILD_PIPELINE_NAME}/jobs/${BUILD_JOB_NAME}/builds/${BUILD_NAME}|${BUILD_PIPELINE_NAME} ${BUILD_JOB_NAME} failed!>
@@ -40,34 +41,29 @@ anchors:
GITHUB_TOKEN: ((github-ci-release-token))
resource_types:
- name: registry-image
type: registry-image
source:
<<: *docker-resource-source
repository: concourse/registry-image-resource
tag: 1.8.0
- name: artifactory-resource
type: registry-image
source:
<<: *docker-resource-source
repository: springio/artifactory-resource
tag: 0.0.18
tag: 0.0.17
- name: github-release
type: registry-image
source:
<<: *docker-resource-source
repository: concourse/github-release-resource
tag: 1.8.0
tag: 1.5.5
- name: github-status-resource
type: registry-image
source:
<<: *docker-resource-source
repository: dpb587/github-status-resource
tag: master
- name: pull-request
type: registry-image
source:
repository: teliaoss/github-pr-resource
tag: v0.23.0
- name: slack-notification
type: registry-image
source:
<<: *docker-resource-source
repository: cfcommunity/slack-notification-resource
tag: latest
resources:
@@ -76,6 +72,13 @@ resources:
icon: github
source:
<<: *git-repo-resource-source
- name: every-morning
type: time
icon: alarm
source:
start: 8:00 AM
stop: 9:00 AM
location: Europe/Vienna
- name: ci-images-git-repo
type: git
icon: github
@@ -84,19 +87,11 @@ resources:
branch: ((branch))
paths: ["ci/images/*"]
- name: ci-image
type: registry-image
type: docker-image
icon: docker
source:
<<: *docker-resource-source
repository: ((docker-hub-organization))/spring-framework-ci
tag: ((milestone))
- name: every-morning
type: time
icon: alarm
source:
start: 8:00 AM
stop: 9:00 AM
location: Europe/Vienna
- name: artifactory-repo
type: artifactory-resource
icon: package-variant
@@ -105,6 +100,14 @@ resources:
username: ((artifactory-username))
password: ((artifactory-password))
build_name: ((build-name))
- name: git-pull-request
type: pull-request
icon: source-pull
source:
access_token: ((github-ci-pull-request-token))
repository: ((github-repo-name))
base_branch: ((branch))
ignore_paths: ["ci/*"]
- name: repo-status-build
type: github-status-resource
icon: eye-check-outline
@@ -113,22 +116,22 @@ resources:
access_token: ((github-ci-status-token))
branch: ((branch))
context: build
- name: repo-status-jdk21-build
- name: repo-status-jdk11-build
type: github-status-resource
icon: eye-check-outline
source:
repository: ((github-repo-name))
access_token: ((github-ci-status-token))
branch: ((branch))
context: jdk21-build
- name: repo-status-jdk22-build
context: jdk11-build
- name: repo-status-jdk17-build
type: github-status-resource
icon: eye-check-outline
source:
repository: ((github-repo-name))
access_token: ((github-ci-status-token))
branch: ((branch))
context: jdk22-build
context: jdk17-build
- name: slack-alert
type: slack-notification
icon: slack
@@ -154,20 +157,13 @@ resources:
jobs:
- name: build-ci-images
plan:
- get: git-repo
- get: ci-images-git-repo
trigger: true
- task: build-ci-image
privileged: true
file: git-repo/ci/tasks/build-ci-image.yml
output_mapping:
image: ci-image
vars:
ci-image-name: ci-image
<<: *docker-resource-source
- get: ci-images-git-repo
trigger: true
- in_parallel:
- put: ci-image
params:
image: ci-image/image.tar
build: ci-images-git-repo/ci/images
dockerfile: ci-images-git-repo/ci/images/ci-image/Dockerfile
- name: build
serial: true
public: true
@@ -206,22 +202,54 @@ jobs:
threads: 8
artifact_set:
- include:
- "/**/framework-api-*.zip"
- "/**/spring-*.zip"
properties:
"zip.name": "spring-framework"
"zip.displayname": "Spring Framework"
"zip.deployed": "false"
- include:
- "/**/framework-api-*-docs.zip"
- "/**/spring-*-docs.zip"
properties:
"zip.type": "docs"
- include:
- "/**/framework-api-*-schema.zip"
- "/**/spring-*-dist.zip"
properties:
"zip.type": "dist"
- include:
- "/**/spring-*-schema.zip"
properties:
"zip.type": "schema"
get_params:
threads: 8
- name: jdk21-build
- name: jdk11-build
serial: true
public: true
plan:
- get: ci-image
- get: git-repo
- get: every-morning
trigger: true
- put: repo-status-jdk11-build
params: { state: "pending", commit: "git-repo" }
- do:
- task: check-project
image: ci-image
file: git-repo/ci/tasks/check-project.yml
privileged: true
timeout: ((task-timeout))
params:
TEST_TOOLCHAIN: 11
<<: *build-project-task-params
on_failure:
do:
- put: repo-status-jdk11-build
params: { state: "failure", commit: "git-repo" }
- put: slack-alert
params:
<<: *slack-fail-params
- put: repo-status-jdk11-build
params: { state: "success", commit: "git-repo" }
- name: jdk17-build
serial: true
public: true
plan:
@@ -229,52 +257,57 @@ jobs:
- get: git-repo
- get: every-morning
trigger: true
- put: repo-status-jdk21-build
- put: repo-status-jdk17-build
params: { state: "pending", commit: "git-repo" }
- do:
- task: check-project
image: ci-image
file: git-repo/ci/tasks/check-project.yml
privileged: true
timeout: ((task-timeout))
params:
TEST_TOOLCHAIN: 21
<<: *build-project-task-params
- task: check-project
image: ci-image
file: git-repo/ci/tasks/check-project.yml
privileged: true
timeout: ((task-timeout))
params:
TEST_TOOLCHAIN: 15
<<: *build-project-task-params
on_failure:
do:
- put: repo-status-jdk21-build
- put: repo-status-jdk17-build
params: { state: "failure", commit: "git-repo" }
- put: slack-alert
params:
<<: *slack-fail-params
- put: repo-status-jdk21-build
- put: repo-status-jdk17-build
params: { state: "success", commit: "git-repo" }
- name: jdk22-build
- name: build-pull-requests
serial: true
public: true
plan:
- get: ci-image
- get: git-repo
- put: repo-status-jdk22-build
params: { state: "pending", commit: "git-repo" }
resource: git-pull-request
trigger: true
version: every
- do:
- task: check-project
image: ci-image
file: git-repo/ci/tasks/check-project.yml
privileged: true
timeout: ((task-timeout))
params:
TEST_TOOLCHAIN: 22
<<: *build-project-task-params
- put: git-pull-request
params:
path: git-repo
status: pending
- task: build-pr
image: ci-image
file: git-repo/ci/tasks/build-pr.yml
privileged: true
timeout: ((task-timeout))
params:
BRANCH: ((branch))
on_success:
put: git-pull-request
params:
path: git-repo
status: success
on_failure:
do:
- put: repo-status-jdk22-build
params: { state: "failure", commit: "git-repo" }
- put: slack-alert
params:
<<: *slack-fail-params
- put: repo-status-jdk22-build
params: { state: "success", commit: "git-repo" }
put: git-pull-request
params:
path: git-repo
status: failure
- name: stage-milestone
serial: true
plan:
@@ -307,6 +340,7 @@ jobs:
download_artifacts: false
save_build_info: true
- task: promote
image: ci-image
file: git-repo/ci/tasks/promote-version.yml
params:
RELEASE_TYPE: M
@@ -316,7 +350,6 @@ jobs:
params:
RELEASE_TYPE: M
<<: *github-task-params
<<: *docker-resource-source
- put: github-pre-release
params:
<<: *changelog-task-params
@@ -352,10 +385,10 @@ jobs:
download_artifacts: false
save_build_info: true
- task: promote
image: ci-image
file: git-repo/ci/tasks/promote-version.yml
params:
RELEASE_TYPE: RC
<<: *docker-resource-source
<<: *artifactory-task-params
- task: generate-changelog
file: git-repo/ci/tasks/generate-changelog.yml
@@ -397,10 +430,10 @@ jobs:
download_artifacts: true
save_build_info: true
- task: promote
image: ci-image
file: git-repo/ci/tasks/promote-version.yml
params:
RELEASE_TYPE: RELEASE
<<: *docker-resource-source
<<: *artifactory-task-params
<<: *sonatype-task-params
- name: create-github-release
@@ -418,7 +451,6 @@ jobs:
file: git-repo/ci/tasks/generate-changelog.yml
params:
RELEASE_TYPE: RELEASE
<<: *docker-resource-source
<<: *github-task-params
- put: github-release
params:
@@ -426,8 +458,10 @@ jobs:
groups:
- name: "builds"
jobs: ["build", "jdk21-build", "jdk22-build"]
jobs: ["build", "jdk11-build", "jdk17-build"]
- name: "releases"
jobs: ["stage-milestone", "stage-rc", "stage-release", "promote-milestone", "promote-rc", "promote-release", "create-github-release"]
- name: "ci-images"
jobs: ["build-ci-images"]
- name: "pull-requests"
jobs: [ "build-pull-requests" ]
+1 -2
View File
@@ -4,6 +4,5 @@ set -e
source $(dirname $0)/common.sh
pushd git-repo > /dev/null
./gradlew -Dorg.gradle.internal.launcher.welcomeMessageEnabled=false -Porg.gradle.java.installations.fromEnv=JDK17,JDK21 \
--no-daemon --max-workers=4 check
./gradlew -Dorg.gradle.internal.launcher.welcomeMessageEnabled=false --no-daemon --max-workers=4 check
popd > /dev/null
+1 -2
View File
@@ -5,6 +5,5 @@ source $(dirname $0)/common.sh
repository=$(pwd)/distribution-repository
pushd git-repo > /dev/null
./gradlew -Dorg.gradle.internal.launcher.welcomeMessageEnabled=false -Porg.gradle.java.installations.fromEnv=JDK17,JDK21,JDK22 \
--no-daemon --max-workers=4 -PdeploymentRepository=${repository} build publishAllPublicationsToDeploymentRepository
./gradlew -Dorg.gradle.internal.launcher.welcomeMessageEnabled=false --no-daemon --max-workers=4 -PdeploymentRepository=${repository} build publishAllPublicationsToDeploymentRepository
popd > /dev/null
+2 -2
View File
@@ -4,6 +4,6 @@ set -e
source $(dirname $0)/common.sh
pushd git-repo > /dev/null
./gradlew -Dorg.gradle.internal.launcher.welcomeMessageEnabled=false -Porg.gradle.java.installations.fromEnv=JDK17,JDK21 \
-PmainToolchain=${MAIN_TOOLCHAIN} -PtestToolchain=${TEST_TOOLCHAIN} --no-daemon --max-workers=4 check antora
./gradlew -Dorg.gradle.internal.launcher.welcomeMessageEnabled=false -Porg.gradle.java.installations.fromEnv=JDK11,JDK15 \
-PmainToolchain=${MAIN_TOOLCHAIN} -PtestToolchain=${TEST_TOOLCHAIN} --no-daemon --max-workers=4 check
popd > /dev/null
+3 -2
View File
@@ -1,15 +1,16 @@
#!/bin/bash
source $(dirname $0)/common.sh
CONFIG_DIR=git-repo/ci/config
version=$( cat artifactory-repo/build-info.json | jq -r '.buildInfo.modules[0].id' | sed 's/.*:.*:\(.*\)/\1/' )
export BUILD_INFO_LOCATION=$(pwd)/artifactory-repo/build-info.json
java -jar /concourse-release-scripts.jar \
java -jar /opt/concourse-release-scripts.jar \
--spring.config.location=${CONFIG_DIR}/release-scripts.yml \
publishToCentral $RELEASE_TYPE $BUILD_INFO_LOCATION artifactory-repo || { exit 1; }
java -jar /concourse-release-scripts.jar \
java -jar /opt/concourse-release-scripts.jar \
--spring.config.location=${CONFIG_DIR}/release-scripts.yml \
promote $RELEASE_TYPE $BUILD_INFO_LOCATION || { exit 1; }
+1 -2
View File
@@ -35,8 +35,7 @@ git add gradle.properties > /dev/null
git commit -m"Release v$stageVersion" > /dev/null
git tag -a "v$stageVersion" -m"Release v$stageVersion" > /dev/null
./gradlew --no-daemon --max-workers=4 -PdeploymentRepository=${repository} -Porg.gradle.java.installations.fromEnv=JDK17,JDK21 \
build publishAllPublicationsToDeploymentRepository
./gradlew --no-daemon --max-workers=4 -PdeploymentRepository=${repository} build publishAllPublicationsToDeploymentRepository
git reset --hard HEAD^ > /dev/null
if [[ $nextVersion != $snapshotVersion ]]; then
+8
View File
@@ -0,0 +1,8 @@
#!/bin/bash
export BUILD_INFO_LOCATION=$(pwd)/artifactory-repo/build-info.json
version=$( cat artifactory-repo/build-info.json | jq -r '.buildInfo.modules[0].id' | sed 's/.*:.*:\(.*\)/\1/' )
java -jar /opt/concourse-release-scripts.jar syncToCentral "RELEASE" $BUILD_INFO_LOCATION || { exit 1; }
echo "Sync complete"
echo $version > version/version
-30
View File
@@ -1,30 +0,0 @@
---
platform: linux
image_resource:
type: registry-image
source:
repository: concourse/oci-build-task
tag: 0.10.0
username: ((docker-hub-username))
password: ((docker-hub-password))
inputs:
- name: ci-images-git-repo
outputs:
- name: image
caches:
- path: ci-image-cache
params:
CONTEXT: ci-images-git-repo/ci/images
DOCKERFILE: ci-images-git-repo/ci/images/ci-image/Dockerfile
DOCKER_HUB_AUTH: ((docker-hub-auth))
run:
path: /bin/sh
args:
- "-c"
- |
mkdir -p /root/.docker
cat > /root/.docker/config.json <<EOF
{ "auths": { "https://index.docker.io/v1/": { "auth": "$DOCKER_HUB_AUTH" }}}
EOF
build
+1 -3
View File
@@ -4,9 +4,7 @@ image_resource:
type: registry-image
source:
repository: springio/github-changelog-generator
tag: '0.0.8'
username: ((docker-hub-username))
password: ((docker-hub-password))
tag: '0.0.7'
inputs:
- name: git-repo
- name: artifactory-repo
+1 -8
View File
@@ -1,12 +1,5 @@
---
platform: linux
image_resource:
type: registry-image
source:
repository: springio/concourse-release-scripts
tag: '0.4.0'
username: ((docker-hub-username))
password: ((docker-hub-password))
inputs:
- name: git-repo
- name: artifactory-repo
@@ -20,6 +13,6 @@ params:
SONATYPE_USER:
SONATYPE_PASSWORD:
SONATYPE_URL:
SONATYPE_STAGING_PROFILE:
SONATYPE_STAGING_PROFILE_ID:
run:
path: git-repo/ci/scripts/promote-version.sh
-119
View File
@@ -1,119 +0,0 @@
plugins {
id 'java-platform'
id 'io.freefair.aggregate-javadoc' version '8.3'
}
description = "Spring Framework API Docs"
apply from: "${rootDir}/gradle/publications.gradle"
repositories {
maven {
url "https://repo.spring.io/release"
}
}
dependencies {
moduleProjects.each { moduleProject ->
javadoc moduleProject
}
}
javadoc {
title = "${rootProject.description} ${version} API"
options {
encoding = "UTF-8"
memberLevel = JavadocMemberLevel.PROTECTED
author = true
header = rootProject.description
use = true
overview = project.relativePath("$rootProject.rootDir/framework-docs/src/docs/api/overview.html")
destinationDir = file("${project.buildDir}/docs/javadoc-api")
splitIndex = true
links(rootProject.ext.javadocLinks)
addBooleanOption('Xdoclint:syntax,reference', true) // only check syntax and reference with doclint
addBooleanOption('Werror', true) // fail build on Javadoc warnings
}
maxMemory = "1024m"
doFirst {
classpath += files(
// ensure the javadoc process can resolve types compiled from .aj sources
project(":spring-aspects").sourceSets.main.output
)
classpath += files(moduleProjects.collect { it.sourceSets.main.compileClasspath })
}
}
/**
* Produce KDoc for all Spring Framework modules in "build/docs/kdoc"
*/
rootProject.tasks.dokkaHtmlMultiModule.configure {
dependsOn {
tasks.named("javadoc")
}
moduleName.set("spring-framework")
outputDirectory.set(project.file("$buildDir/docs/kdoc-api"))
includes.from("$rootProject.rootDir/framework-docs/src/docs/api/dokka-overview.md")
}
/**
* Zip all Java docs (javadoc & kdoc) into a single archive
*/
tasks.register('docsZip', Zip) {
dependsOn = ['javadoc', rootProject.tasks.dokkaHtmlMultiModule]
group = "distribution"
description = "Builds -${archiveClassifier} archive containing api and reference " +
"for deployment at https://docs.spring.io/spring-framework/docs/."
archiveBaseName.set("spring-framework")
archiveClassifier.set("docs")
from("src/dist") {
include "changelog.txt"
}
from(javadoc) {
into "javadoc-api"
}
from(rootProject.tasks.dokkaHtmlMultiModule.outputDirectory) {
into "kdoc-api"
}
}
/**
* Zip all Spring Framework schemas into a single archive
*/
tasks.register('schemaZip', Zip) {
group = "distribution"
archiveBaseName.set("spring-framework")
archiveClassifier.set("schema")
description = "Builds -${archiveClassifier} archive containing all " +
"XSDs for deployment at https://springframework.org/schema."
duplicatesStrategy DuplicatesStrategy.EXCLUDE
moduleProjects.each { module ->
def Properties schemas = new Properties();
module.sourceSets.main.resources.find {
(it.path.endsWith("META-INF/spring.schemas") || it.path.endsWith("META-INF\\spring.schemas"))
}?.withInputStream { schemas.load(it) }
for (def key : schemas.keySet()) {
def shortName = key.replaceAll(/http.*schema.(.*).spring-.*/, '$1')
assert shortName != key
File xsdFile = module.sourceSets.main.resources.find {
(it.path.endsWith(schemas.get(key)) || it.path.endsWith(schemas.get(key).replaceAll('\\/', '\\\\')))
}
assert xsdFile != null
into(shortName) {
from xsdFile.path
}
}
}
}
publishing {
publications {
mavenJava(MavenPublication) {
artifact docsZip
artifact schemaZip
}
}
}
-89
View File
@@ -1,89 +0,0 @@
name: framework
version: true
title: Spring Framework
nav:
- modules/ROOT/nav.adoc
ext:
collector:
run:
command: gradlew -q -PbuildSrc.skipTests=true "-Dorg.gradle.jvmargs=-Xmx3g -XX:+HeapDumpOnOutOfMemoryError" :framework-docs:generateAntoraResources
local: true
scan:
dir: ./build/generated-antora-resources
asciidoc:
attributes:
attribute-missing: 'warn'
# FIXME: the copyright is not removed
# FIXME: The package is not renamed
chomp: 'all'
fold: 'all'
include-java: 'example$docs-src/main/java/org/springframework/docs'
spring-site: 'https://spring.io'
spring-site-blog: '{spring-site}/blog'
spring-site-cve: "{spring-site}/security"
spring-site-guides: '{spring-site}/guides'
spring-site-projects: '{spring-site}/projects'
spring-site-tools: "{spring-site}/tools"
spring-org: 'spring-projects'
spring-github-org: "https://github.com/{spring-org}"
spring-framework-github: "https://github.com/{spring-org}/spring-framework"
spring-framework-code: '{spring-framework-github}/tree/main'
spring-framework-issues: '{spring-framework-github}/issues'
spring-framework-wiki: '{spring-framework-github}/wiki'
# Docs
docs-site: 'https://docs.spring.io'
spring-framework-docs-root: '{docs-site}/spring-framework/docs'
spring-framework-api: '{spring-framework-docs-root}/{spring-version}/javadoc-api/org/springframework'
spring-framework-api-kdoc: '{spring-framework-docs-root}/{spring-version}/kdoc-api'
spring-framework-reference: '{spring-framework-docs-root}/{spring-version}/reference'
#
# Other Spring portfolio projects
spring-boot-docs: '{docs-site}/spring-boot/docs/current/reference/html'
spring-boot-issues: '{spring-github-org}/spring-boot/issues'
# TODO add more projects / links or just build up on {docs-site}?
# TODO rename the below using new conventions
docs-spring-gemfire: '{docs-site}/spring-gemfire/docs/current/reference'
docs-spring-security: '{docs-site}/spring-security/reference'
docs-spring-session: '{docs-site}/spring-session/reference'
#
# External projects URLs and related attributes
aspectj-site: 'https://www.eclipse.org/aspectj'
aspectj-docs: "{aspectj-site}/doc/released"
aspectj-api: "{aspectj-docs}/runtime-api"
aspectj-docs-devguide: "{aspectj-docs}/devguide"
aspectj-docs-progguide: "{aspectj-docs}/progguide"
assertj-docs: 'https://assertj.github.io/doc'
baeldung-blog: 'https://www.baeldung.com'
bean-validation-site: 'https://beanvalidation.org'
graalvm-docs: 'https://www.graalvm.org/22.3/reference-manual'
hibernate-validator-site: 'https://hibernate.org/validator/'
jackson-docs: 'https://fasterxml.github.io'
jackson-github-org: 'https://github.com/FasterXML'
java-api: 'https://docs.oracle.com/en/java/javase/17/docs/api'
java-tutorial: 'https://docs.oracle.com/javase/tutorial'
JSR: 'https://www.jcp.org/en/jsr/detail?id='
kotlin-site: 'https://kotlinlang.org'
kotlin-docs: '{kotlin-site}/docs'
kotlin-api: '{kotlin-site}/api/latest'
kotlin-coroutines-api: '{kotlin-site}/api/kotlinx.coroutines'
kotlin-github-org: 'https://github.com/Kotlin'
kotlin-issues: 'https://youtrack.jetbrains.com/issue'
reactive-streams-site: 'https://www.reactive-streams.org'
reactive-streams-spec: 'https://github.com/reactive-streams/reactive-streams-jvm/blob/master/README.md#specification'
reactor-github-org: 'https://github.com/reactor'
reactor-site: 'https://projectreactor.io'
rsocket-github-org: 'https://github.com/rsocket'
rsocket-java: '{rsocket-github-org}/rsocket-java'
rsocket-java-code: '{rsocket-java}/tree/master/'
rsocket-protocol-extensions: '{rsocket-github-org}/rsocket/tree/master/Extensions'
rsocket-site: 'https://rsocket.io'
rfc-site: 'https://datatracker.ietf.org/doc/html'
sockjs-client: 'https://github.com/sockjs/sockjs-client'
sockjs-protocol: 'https://github.com/sockjs/sockjs-protocol'
sockjs-protocol-site: "https://sockjs.github.io/sockjs-protocol"
stackoverflow-site: 'https://stackoverflow.com'
stackoverflow-questions: '{stackoverflow-site}/questions'
stackoverflow-spring-tag: "{stackoverflow-questions}/tagged/spring"
stackoverflow-spring-kotlin-tags: "{stackoverflow-spring-tag}+kotlin"
testcontainers-site: 'https://www.testcontainers.org'
-70
View File
@@ -1,70 +0,0 @@
plugins {
id 'kotlin'
id 'io.spring.antora.generate-antora-yml' version '0.0.1'
id 'org.antora' version '1.0.0'
}
description = "Spring Framework Docs"
apply from: "${rootDir}/gradle/ide.gradle"
apply from: "${rootDir}/gradle/publications.gradle"
antora {
version = '3.2.0-alpha.2'
playbook = 'cached-antora-playbook.yml'
playbookProvider {
repository = 'spring-projects/spring-framework'
branch = 'docs-build'
path = 'lib/antora/templates/per-branch-antora-playbook.yml'
checkLocalBranch = true
}
options = ['--clean', '--stacktrace']
environment = [
'ALGOLIA_API_KEY': '82c7ead946afbac3cf98c32446154691',
'ALGOLIA_APP_ID': '244V8V9FGG',
'ALGOLIA_INDEX_NAME': 'framework-docs'
]
dependencies = [
'@antora/atlas-extension': '1.0.0-alpha.1',
'@antora/collector-extension': '1.0.0-alpha.3',
'@asciidoctor/tabs': '1.0.0-beta.3',
'@opendevise/antora-release-line-extension': '1.0.0-alpha.2',
'@springio/antora-extensions': '1.3.0',
'@springio/asciidoctor-extensions': '1.0.0-alpha.9'
]
}
tasks.named("generateAntoraYml") {
asciidocAttributes = project.provider( {
return ["spring-version": project.version ]
} )
}
tasks.register("generateAntoraResources") {
dependsOn 'generateAntoraYml'
}
jar {
enabled = false
}
javadoc {
enabled = false
}
repositories {
maven {
url "https://repo.spring.io/release"
}
}
dependencies {
api(project(":spring-context"))
api(project(":spring-jms"))
api(project(":spring-web"))
api("jakarta.jms:jakarta.jms-api")
api("jakarta.servlet:jakarta.servlet-api")
implementation(project(":spring-core-test"))
implementation("org.assertj:assertj-core")
}
@@ -1 +0,0 @@
../../../src
-442
View File
@@ -1,442 +0,0 @@
* xref:overview.adoc[Overview]
* xref:core.adoc[]
** xref:core/beans.adoc[]
*** xref:core/beans/introduction.adoc[]
*** xref:core/beans/basics.adoc[]
*** xref:core/beans/definition.adoc[]
*** xref:core/beans/dependencies.adoc[]
**** xref:core/beans/dependencies/factory-collaborators.adoc[]
**** xref:core/beans/dependencies/factory-properties-detailed.adoc[]
**** xref:core/beans/dependencies/factory-dependson.adoc[]
**** xref:core/beans/dependencies/factory-lazy-init.adoc[]
**** xref:core/beans/dependencies/factory-autowire.adoc[]
**** xref:core/beans/dependencies/factory-method-injection.adoc[]
*** xref:core/beans/factory-scopes.adoc[]
*** xref:core/beans/factory-nature.adoc[]
*** xref:core/beans/child-bean-definitions.adoc[]
*** xref:core/beans/factory-extension.adoc[]
*** xref:core/beans/annotation-config.adoc[]
**** xref:core/beans/annotation-config/autowired.adoc[]
**** xref:core/beans/annotation-config/autowired-primary.adoc[]
**** xref:core/beans/annotation-config/autowired-qualifiers.adoc[]
**** xref:core/beans/annotation-config/generics-as-qualifiers.adoc[]
**** xref:core/beans/annotation-config/custom-autowire-configurer.adoc[]
**** xref:core/beans/annotation-config/resource.adoc[]
**** xref:core/beans/annotation-config/value-annotations.adoc[]
**** xref:core/beans/annotation-config/postconstruct-and-predestroy-annotations.adoc[]
*** xref:core/beans/classpath-scanning.adoc[]
*** xref:core/beans/standard-annotations.adoc[]
*** xref:core/beans/java.adoc[]
**** xref:core/beans/java/basic-concepts.adoc[]
**** xref:core/beans/java/instantiating-container.adoc[]
**** xref:core/beans/java/bean-annotation.adoc[]
**** xref:core/beans/java/configuration-annotation.adoc[]
**** xref:core/beans/java/composing-configuration-classes.adoc[]
*** xref:core/beans/environment.adoc[]
*** xref:core/beans/context-load-time-weaver.adoc[]
*** xref:core/beans/context-introduction.adoc[]
*** xref:core/beans/beanfactory.adoc[]
** xref:core/resources.adoc[]
** xref:core/validation.adoc[]
*** xref:core/validation/validator.adoc[]
*** xref:core/validation/conversion.adoc[]
*** xref:core/validation/beans-beans.adoc[]
*** xref:core/validation/convert.adoc[]
*** xref:core/validation/format.adoc[]
*** xref:core/validation/format-configuring-formatting-globaldatetimeformat.adoc[]
*** xref:core/validation/beanvalidation.adoc[]
** xref:core/expressions.adoc[]
*** xref:core/expressions/evaluation.adoc[]
*** xref:core/expressions/beandef.adoc[]
*** xref:core/expressions/language-ref.adoc[]
**** xref:core/expressions/language-ref/literal.adoc[]
**** xref:core/expressions/language-ref/properties-arrays.adoc[]
**** xref:core/expressions/language-ref/inline-lists.adoc[]
**** xref:core/expressions/language-ref/inline-maps.adoc[]
**** xref:core/expressions/language-ref/array-construction.adoc[]
**** xref:core/expressions/language-ref/methods.adoc[]
**** xref:core/expressions/language-ref/operators.adoc[]
**** xref:core/expressions/language-ref/types.adoc[]
**** xref:core/expressions/language-ref/constructors.adoc[]
**** xref:core/expressions/language-ref/variables.adoc[]
**** xref:core/expressions/language-ref/functions.adoc[]
**** xref:core/expressions/language-ref/bean-references.adoc[]
**** xref:core/expressions/language-ref/operator-ternary.adoc[]
**** xref:core/expressions/language-ref/operator-elvis.adoc[]
**** xref:core/expressions/language-ref/operator-safe-navigation.adoc[]
**** xref:core/expressions/language-ref/collection-selection.adoc[]
**** xref:core/expressions/language-ref/collection-projection.adoc[]
**** xref:core/expressions/language-ref/templating.adoc[]
*** xref:core/expressions/example-classes.adoc[]
** xref:core/aop.adoc[]
*** xref:core/aop/introduction-defn.adoc[]
*** xref:core/aop/introduction-spring-defn.adoc[]
*** xref:core/aop/introduction-proxies.adoc[]
*** xref:core/aop/ataspectj.adoc[]
**** xref:core/aop/ataspectj/aspectj-support.adoc[]
**** xref:core/aop/ataspectj/at-aspectj.adoc[]
**** xref:core/aop/ataspectj/pointcuts.adoc[]
**** xref:core/aop/ataspectj/advice.adoc[]
**** xref:core/aop/ataspectj/introductions.adoc[]
**** xref:core/aop/ataspectj/instantiation-models.adoc[]
**** xref:core/aop/ataspectj/example.adoc[]
*** xref:core/aop/schema.adoc[]
*** xref:core/aop/choosing.adoc[]
*** xref:core/aop/mixing-styles.adoc[]
*** xref:core/aop/proxying.adoc[]
*** xref:core/aop/aspectj-programmatic.adoc[]
*** xref:core/aop/using-aspectj.adoc[]
*** xref:core/aop/resources.adoc[]
** xref:core/aop-api.adoc[]
*** xref:core/aop-api/pointcuts.adoc[]
*** xref:core/aop-api/advice.adoc[]
*** xref:core/aop-api/advisor.adoc[]
*** xref:core/aop-api/pfb.adoc[]
*** xref:core/aop-api/concise-proxy.adoc[]
*** xref:core/aop-api/prog.adoc[]
*** xref:core/aop-api/advised.adoc[]
*** xref:core/aop-api/autoproxy.adoc[]
*** xref:core/aop-api/targetsource.adoc[]
*** xref:core/aop-api/extensibility.adoc[]
** xref:core/null-safety.adoc[]
** xref:core/databuffer-codec.adoc[]
** xref:core/spring-jcl.adoc[]
** xref:core/aot.adoc[]
** xref:core/appendix.adoc[]
*** xref:core/appendix/xsd-schemas.adoc[]
*** xref:core/appendix/xml-custom.adoc[]
*** xref:core/appendix/application-startup-steps.adoc[]
* xref:testing.adoc[]
** xref:testing/introduction.adoc[]
** xref:testing/unit.adoc[]
** xref:testing/integration.adoc[]
** xref:testing/support-jdbc.adoc[]
** xref:testing/testcontext-framework.adoc[]
*** xref:testing/testcontext-framework/key-abstractions.adoc[]
*** xref:testing/testcontext-framework/bootstrapping.adoc[]
*** xref:testing/testcontext-framework/tel-config.adoc[]
*** xref:testing/testcontext-framework/application-events.adoc[]
*** xref:testing/testcontext-framework/test-execution-events.adoc[]
*** xref:testing/testcontext-framework/ctx-management.adoc[]
**** xref:testing/testcontext-framework/ctx-management/xml.adoc[]
**** xref:testing/testcontext-framework/ctx-management/groovy.adoc[]
**** xref:testing/testcontext-framework/ctx-management/javaconfig.adoc[]
**** xref:testing/testcontext-framework/ctx-management/mixed-config.adoc[]
**** xref:testing/testcontext-framework/ctx-management/context-customizers.adoc[]
**** xref:testing/testcontext-framework/ctx-management/initializers.adoc[]
**** xref:testing/testcontext-framework/ctx-management/inheritance.adoc[]
**** xref:testing/testcontext-framework/ctx-management/env-profiles.adoc[]
**** xref:testing/testcontext-framework/ctx-management/property-sources.adoc[]
**** xref:testing/testcontext-framework/ctx-management/dynamic-property-sources.adoc[]
**** xref:testing/testcontext-framework/ctx-management/web.adoc[]
**** xref:testing/testcontext-framework/ctx-management/web-mocks.adoc[]
**** xref:testing/testcontext-framework/ctx-management/caching.adoc[]
**** xref:testing/testcontext-framework/ctx-management/failure-threshold.adoc[]
**** xref:testing/testcontext-framework/ctx-management/hierarchies.adoc[]
*** xref:testing/testcontext-framework/fixture-di.adoc[]
*** xref:testing/testcontext-framework/web-scoped-beans.adoc[]
*** xref:testing/testcontext-framework/tx.adoc[]
*** xref:testing/testcontext-framework/executing-sql.adoc[]
*** xref:testing/testcontext-framework/parallel-test-execution.adoc[]
*** xref:testing/testcontext-framework/support-classes.adoc[]
*** xref:testing/testcontext-framework/aot.adoc[]
** xref:testing/webtestclient.adoc[]
** xref:testing/spring-mvc-test-framework.adoc[]
*** xref:testing/spring-mvc-test-framework/server.adoc[]
*** xref:testing/spring-mvc-test-framework/server-static-imports.adoc[]
*** xref:testing/spring-mvc-test-framework/server-setup-options.adoc[]
*** xref:testing/spring-mvc-test-framework/server-setup-steps.adoc[]
*** xref:testing/spring-mvc-test-framework/server-performing-requests.adoc[]
*** xref:testing/spring-mvc-test-framework/server-defining-expectations.adoc[]
*** xref:testing/spring-mvc-test-framework/async-requests.adoc[]
*** xref:testing/spring-mvc-test-framework/vs-streaming-response.adoc[]
*** xref:testing/spring-mvc-test-framework/server-filters.adoc[]
*** xref:testing/spring-mvc-test-framework/vs-end-to-end-integration-tests.adoc[]
*** xref:testing/spring-mvc-test-framework/server-resources.adoc[]
*** xref:testing/spring-mvc-test-framework/server-htmlunit.adoc[]
**** xref:testing/spring-mvc-test-framework/server-htmlunit/why.adoc[]
**** xref:testing/spring-mvc-test-framework/server-htmlunit/mah.adoc[]
**** xref:testing/spring-mvc-test-framework/server-htmlunit/webdriver.adoc[]
**** xref:testing/spring-mvc-test-framework/server-htmlunit/geb.adoc[]
** xref:testing/spring-mvc-test-client.adoc[]
** xref:testing/appendix.adoc[]
*** xref:testing/annotations.adoc[]
**** xref:testing/annotations/integration-standard.adoc[]
**** xref:testing/annotations/integration-spring.adoc[]
***** xref:testing/annotations/integration-spring/annotation-bootstrapwith.adoc[]
***** xref:testing/annotations/integration-spring/annotation-contextconfiguration.adoc[]
***** xref:testing/annotations/integration-spring/annotation-webappconfiguration.adoc[]
***** xref:testing/annotations/integration-spring/annotation-contexthierarchy.adoc[]
***** xref:testing/annotations/integration-spring/annotation-contextcustomizerfactories.adoc[]
***** xref:testing/annotations/integration-spring/annotation-activeprofiles.adoc[]
***** xref:testing/annotations/integration-spring/annotation-testpropertysource.adoc[]
***** xref:testing/annotations/integration-spring/annotation-dynamicpropertysource.adoc[]
***** xref:testing/annotations/integration-spring/annotation-dirtiescontext.adoc[]
***** xref:testing/annotations/integration-spring/annotation-testexecutionlisteners.adoc[]
***** xref:testing/annotations/integration-spring/annotation-recordapplicationevents.adoc[]
***** xref:testing/annotations/integration-spring/annotation-commit.adoc[]
***** xref:testing/annotations/integration-spring/annotation-rollback.adoc[]
***** xref:testing/annotations/integration-spring/annotation-beforetransaction.adoc[]
***** xref:testing/annotations/integration-spring/annotation-aftertransaction.adoc[]
***** xref:testing/annotations/integration-spring/annotation-sql.adoc[]
***** xref:testing/annotations/integration-spring/annotation-sqlconfig.adoc[]
***** xref:testing/annotations/integration-spring/annotation-sqlmergemode.adoc[]
***** xref:testing/annotations/integration-spring/annotation-sqlgroup.adoc[]
***** xref:testing/annotations/integration-spring/annotation-disabledinaotmode.adoc[]
**** xref:testing/annotations/integration-junit4.adoc[]
**** xref:testing/annotations/integration-junit-jupiter.adoc[]
**** xref:testing/annotations/integration-meta.adoc[]
*** xref:testing/resources.adoc[]
* xref:data-access.adoc[]
** xref:data-access/transaction.adoc[]
*** xref:data-access/transaction/motivation.adoc[]
*** xref:data-access/transaction/strategies.adoc[]
*** xref:data-access/transaction/tx-resource-synchronization.adoc[]
*** xref:data-access/transaction/declarative.adoc[]
**** xref:data-access/transaction/declarative/tx-decl-explained.adoc[]
**** xref:data-access/transaction/declarative/first-example.adoc[]
**** xref:data-access/transaction/declarative/rolling-back.adoc[]
**** xref:data-access/transaction/declarative/diff-tx.adoc[]
**** xref:data-access/transaction/declarative/txadvice-settings.adoc[]
**** xref:data-access/transaction/declarative/annotations.adoc[]
**** xref:data-access/transaction/declarative/tx-propagation.adoc[]
**** xref:data-access/transaction/declarative/applying-more-than-just-tx-advice.adoc[]
**** xref:data-access/transaction/declarative/aspectj.adoc[]
*** xref:data-access/transaction/programmatic.adoc[]
*** xref:data-access/transaction/tx-decl-vs-prog.adoc[]
*** xref:data-access/transaction/event.adoc[]
*** xref:data-access/transaction/application-server-integration.adoc[]
*** xref:data-access/transaction/solutions-to-common-problems.adoc[]
*** xref:data-access/transaction/resources.adoc[]
** xref:data-access/dao.adoc[]
** xref:data-access/jdbc.adoc[]
*** xref:data-access/jdbc/choose-style.adoc[]
*** xref:data-access/jdbc/packages.adoc[]
*** xref:data-access/jdbc/core.adoc[]
*** xref:data-access/jdbc/connections.adoc[]
*** xref:data-access/jdbc/advanced.adoc[]
*** xref:data-access/jdbc/simple.adoc[]
*** xref:data-access/jdbc/object.adoc[]
*** xref:data-access/jdbc/parameter-handling.adoc[]
*** xref:data-access/jdbc/embedded-database-support.adoc[]
*** xref:data-access/jdbc/initializing-datasource.adoc[]
** xref:data-access/r2dbc.adoc[]
** xref:data-access/orm.adoc[]
*** xref:data-access/orm/introduction.adoc[]
*** xref:data-access/orm/general.adoc[]
*** xref:data-access/orm/hibernate.adoc[]
*** xref:data-access/orm/jpa.adoc[]
** xref:data-access/oxm.adoc[]
** xref:data-access/appendix.adoc[]
* xref:web.adoc[]
** xref:web/webmvc.adoc[]
*** xref:web/webmvc/mvc-servlet.adoc[]
**** xref:web/webmvc/mvc-servlet/context-hierarchy.adoc[]
**** xref:web/webmvc/mvc-servlet/special-bean-types.adoc[]
**** xref:web/webmvc/mvc-servlet/config.adoc[]
**** xref:web/webmvc/mvc-servlet/container-config.adoc[]
**** xref:web/webmvc/mvc-servlet/sequence.adoc[]
**** xref:web/webmvc/mvc-servlet/handlermapping-path.adoc[]
**** xref:web/webmvc/mvc-servlet/handlermapping-interceptor.adoc[]
**** xref:web/webmvc/mvc-servlet/exceptionhandlers.adoc[]
**** xref:web/webmvc/mvc-servlet/viewresolver.adoc[]
**** xref:web/webmvc/mvc-servlet/localeresolver.adoc[]
**** xref:web/webmvc/mvc-servlet/themeresolver.adoc[]
**** xref:web/webmvc/mvc-servlet/multipart.adoc[]
**** xref:web/webmvc/mvc-servlet/logging.adoc[]
*** xref:web/webmvc/filters.adoc[]
*** xref:web/webmvc/mvc-controller.adoc[]
**** xref:web/webmvc/mvc-controller/ann.adoc[]
**** xref:web/webmvc/mvc-controller/ann-requestmapping.adoc[]
**** xref:web/webmvc/mvc-controller/ann-methods.adoc[]
***** xref:web/webmvc/mvc-controller/ann-methods/arguments.adoc[]
***** xref:web/webmvc/mvc-controller/ann-methods/return-types.adoc[]
***** xref:web/webmvc/mvc-controller/ann-methods/typeconversion.adoc[]
***** xref:web/webmvc/mvc-controller/ann-methods/matrix-variables.adoc[]
***** xref:web/webmvc/mvc-controller/ann-methods/requestparam.adoc[]
***** xref:web/webmvc/mvc-controller/ann-methods/requestheader.adoc[]
***** xref:web/webmvc/mvc-controller/ann-methods/cookievalue.adoc[]
***** xref:web/webmvc/mvc-controller/ann-methods/modelattrib-method-args.adoc[]
***** xref:web/webmvc/mvc-controller/ann-methods/sessionattributes.adoc[]
***** xref:web/webmvc/mvc-controller/ann-methods/sessionattribute.adoc[]
***** xref:web/webmvc/mvc-controller/ann-methods/requestattrib.adoc[]
***** xref:web/webmvc/mvc-controller/ann-methods/redirecting-passing-data.adoc[]
***** xref:web/webmvc/mvc-controller/ann-methods/flash-attributes.adoc[]
***** xref:web/webmvc/mvc-controller/ann-methods/multipart-forms.adoc[]
***** xref:web/webmvc/mvc-controller/ann-methods/requestbody.adoc[]
***** xref:web/webmvc/mvc-controller/ann-methods/httpentity.adoc[]
***** xref:web/webmvc/mvc-controller/ann-methods/responsebody.adoc[]
***** xref:web/webmvc/mvc-controller/ann-methods/responseentity.adoc[]
***** xref:web/webmvc/mvc-controller/ann-methods/jackson.adoc[]
**** xref:web/webmvc/mvc-controller/ann-modelattrib-methods.adoc[]
**** xref:web/webmvc/mvc-controller/ann-initbinder.adoc[]
**** xref:web/webmvc/mvc-controller/ann-validation.adoc[]
**** xref:web/webmvc/mvc-controller/ann-exceptionhandler.adoc[]
**** xref:web/webmvc/mvc-controller/ann-advice.adoc[]
*** xref:web/webmvc-functional.adoc[]
*** xref:web/webmvc/mvc-uri-building.adoc[]
*** xref:web/webmvc/mvc-ann-async.adoc[]
*** xref:web/webmvc-cors.adoc[]
*** xref:web/webmvc/mvc-ann-rest-exceptions.adoc[]
*** xref:web/webmvc/mvc-security.adoc[]
*** xref:web/webmvc/mvc-caching.adoc[]
*** xref:web/webmvc-view.adoc[]
**** xref:web/webmvc-view/mvc-thymeleaf.adoc[]
**** xref:web/webmvc-view/mvc-freemarker.adoc[]
**** xref:web/webmvc-view/mvc-groovymarkup.adoc[]
**** xref:web/webmvc-view/mvc-script.adoc[]
**** xref:web/webmvc-view/mvc-jsp.adoc[]
**** xref:web/webmvc-view/mvc-feeds.adoc[]
**** xref:web/webmvc-view/mvc-document.adoc[]
**** xref:web/webmvc-view/mvc-jackson.adoc[]
**** xref:web/webmvc-view/mvc-xml-marshalling.adoc[]
**** xref:web/webmvc-view/mvc-xslt.adoc[]
*** xref:web/webmvc/mvc-config.adoc[]
**** xref:web/webmvc/mvc-config/enable.adoc[]
**** xref:web/webmvc/mvc-config/customize.adoc[]
**** xref:web/webmvc/mvc-config/conversion.adoc[]
**** xref:web/webmvc/mvc-config/validation.adoc[]
**** xref:web/webmvc/mvc-config/interceptors.adoc[]
**** xref:web/webmvc/mvc-config/content-negotiation.adoc[]
**** xref:web/webmvc/mvc-config/message-converters.adoc[]
**** xref:web/webmvc/mvc-config/view-controller.adoc[]
**** xref:web/webmvc/mvc-config/view-resolvers.adoc[]
**** xref:web/webmvc/mvc-config/static-resources.adoc[]
**** xref:web/webmvc/mvc-config/default-servlet-handler.adoc[]
**** xref:web/webmvc/mvc-config/path-matching.adoc[]
**** xref:web/webmvc/mvc-config/advanced-java.adoc[]
**** xref:web/webmvc/mvc-config/advanced-xml.adoc[]
*** xref:web/webmvc/mvc-http2.adoc[]
** xref:web/webmvc-client.adoc[]
** xref:web/webmvc-test.adoc[]
** xref:web/websocket.adoc[]
*** xref:web/websocket/server.adoc[]
*** xref:web/websocket/fallback.adoc[]
*** xref:web/websocket/stomp.adoc[]
**** xref:web/websocket/stomp/overview.adoc[]
**** xref:web/websocket/stomp/benefits.adoc[]
**** xref:web/websocket/stomp/enable.adoc[]
**** xref:web/websocket/stomp/server-config.adoc[]
**** xref:web/websocket/stomp/message-flow.adoc[]
**** xref:web/websocket/stomp/handle-annotations.adoc[]
**** xref:web/websocket/stomp/handle-send.adoc[]
**** xref:web/websocket/stomp/handle-simple-broker.adoc[]
**** xref:web/websocket/stomp/handle-broker-relay.adoc[]
**** xref:web/websocket/stomp/handle-broker-relay-configure.adoc[]
**** xref:web/websocket/stomp/destination-separator.adoc[]
**** xref:web/websocket/stomp/authentication.adoc[]
**** xref:web/websocket/stomp/authentication-token-based.adoc[]
**** xref:web/websocket/stomp/authorization.adoc[]
**** xref:web/websocket/stomp/user-destination.adoc[]
**** xref:web/websocket/stomp/ordered-messages.adoc[]
**** xref:web/websocket/stomp/application-context-events.adoc[]
**** xref:web/websocket/stomp/interceptors.adoc[]
**** xref:web/websocket/stomp/client.adoc[]
**** xref:web/websocket/stomp/scope.adoc[]
**** xref:web/websocket/stomp/configuration-performance.adoc[]
**** xref:web/websocket/stomp/stats.adoc[]
**** xref:web/websocket/stomp/testing.adoc[]
** xref:web/integration.adoc[]
* xref:web-reactive.adoc[]
** xref:web/webflux.adoc[]
*** xref:web/webflux/new-framework.adoc[]
*** xref:web/webflux/reactive-spring.adoc[]
*** xref:web/webflux/dispatcher-handler.adoc[]
*** xref:web/webflux/controller.adoc[]
**** xref:web/webflux/controller/ann.adoc[]
**** xref:web/webflux/controller/ann-requestmapping.adoc[]
**** xref:web/webflux/controller/ann-methods.adoc[]
***** xref:web/webflux/controller/ann-methods/arguments.adoc[]
***** xref:web/webflux/controller/ann-methods/return-types.adoc[]
***** xref:web/webflux/controller/ann-methods/typeconversion.adoc[]
***** xref:web/webflux/controller/ann-methods/matrix-variables.adoc[]
***** xref:web/webflux/controller/ann-methods/requestparam.adoc[]
***** xref:web/webflux/controller/ann-methods/requestheader.adoc[]
***** xref:web/webflux/controller/ann-methods/cookievalue.adoc[]
***** xref:web/webflux/controller/ann-methods/modelattrib-method-args.adoc[]
***** xref:web/webflux/controller/ann-methods/sessionattributes.adoc[]
***** xref:web/webflux/controller/ann-methods/sessionattribute.adoc[]
***** xref:web/webflux/controller/ann-methods/requestattrib.adoc[]
***** xref:web/webflux/controller/ann-methods/multipart-forms.adoc[]
***** xref:web/webflux/controller/ann-methods/requestbody.adoc[]
***** xref:web/webflux/controller/ann-methods/httpentity.adoc[]
***** xref:web/webflux/controller/ann-methods/responsebody.adoc[]
***** xref:web/webflux/controller/ann-methods/responseentity.adoc[]
***** xref:web/webflux/controller/ann-methods/jackson.adoc[]
**** xref:web/webflux/controller/ann-modelattrib-methods.adoc[]
**** xref:web/webflux/controller/ann-initbinder.adoc[]
**** xref:web/webflux/controller/ann-validation.adoc[]
**** xref:web/webflux/controller/ann-exceptions.adoc[]
**** xref:web/webflux/controller/ann-advice.adoc[]
*** xref:web/webflux-functional.adoc[]
*** xref:web/webflux/uri-building.adoc[]
*** xref:web/webflux-cors.adoc[]
*** xref:web/webflux/ann-rest-exceptions.adoc[]
*** xref:web/webflux/security.adoc[]
*** xref:web/webflux/caching.adoc[]
*** xref:web/webflux-view.adoc[]
*** xref:web/webflux/config.adoc[]
*** xref:web/webflux/http2.adoc[]
** xref:web/webflux-webclient.adoc[]
*** xref:web/webflux-webclient/client-builder.adoc[]
*** xref:web/webflux-webclient/client-retrieve.adoc[]
*** xref:web/webflux-webclient/client-exchange.adoc[]
*** xref:web/webflux-webclient/client-body.adoc[]
*** xref:web/webflux-webclient/client-filter.adoc[]
*** xref:web/webflux-webclient/client-attributes.adoc[]
*** xref:web/webflux-webclient/client-context.adoc[]
*** xref:web/webflux-webclient/client-synchronous.adoc[]
*** xref:web/webflux-webclient/client-testing.adoc[]
** xref:web/webflux-http-interface-client.adoc[]
** xref:web/webflux-websocket.adoc[]
** xref:web/webflux-test.adoc[]
** xref:rsocket.adoc[]
** xref:web/webflux-reactive-libraries.adoc[]
* xref:integration.adoc[]
** xref:integration/rest-clients.adoc[]
** xref:integration/jms.adoc[]
*** xref:integration/jms/using.adoc[]
*** xref:integration/jms/sending.adoc[]
*** xref:integration/jms/receiving.adoc[]
*** xref:integration/jms/jca-message-endpoint-manager.adoc[]
*** xref:integration/jms/annotated.adoc[]
*** xref:integration/jms/namespace.adoc[]
** xref:integration/jmx.adoc[]
*** xref:integration/jmx/exporting.adoc[]
*** xref:integration/jmx/interface.adoc[]
*** xref:integration/jmx/naming.adoc[]
*** xref:integration/jmx/jsr160.adoc[]
*** xref:integration/jmx/proxy.adoc[]
*** xref:integration/jmx/notifications.adoc[]
*** xref:integration/jmx/resources.adoc[]
** xref:integration/email.adoc[]
** xref:integration/scheduling.adoc[]
** xref:integration/cache.adoc[]
*** xref:integration/cache/strategies.adoc[]
*** xref:integration/cache/annotations.adoc[]
*** xref:integration/cache/jsr-107.adoc[]
*** xref:integration/cache/declarative-xml.adoc[]
*** xref:integration/cache/store-configuration.adoc[]
*** xref:integration/cache/plug.adoc[]
*** xref:integration/cache/specific-config.adoc[]
** xref:integration/observability.adoc[]
** xref:integration/checkpoint-restore.adoc[]
** xref:integration/class-data-sharing.adoc[]
** xref:integration/appendix.adoc[]
* xref:languages.adoc[]
** xref:languages/kotlin.adoc[]
*** xref:languages/kotlin/requirements.adoc[]
*** xref:languages/kotlin/extensions.adoc[]
*** xref:languages/kotlin/null-safety.adoc[]
*** xref:languages/kotlin/classes-interfaces.adoc[]
*** xref:languages/kotlin/annotations.adoc[]
*** xref:languages/kotlin/bean-definition-dsl.adoc[]
*** xref:languages/kotlin/web.adoc[]
*** xref:languages/kotlin/coroutines.adoc[]
*** xref:languages/kotlin/spring-projects-in.adoc[]
*** xref:languages/kotlin/getting-started.adoc[]
*** xref:languages/kotlin/resources.adoc[]
** xref:languages/groovy.adoc[]
** xref:languages/dynamic.adoc[]
* xref:appendix.adoc[]
* {spring-framework-wiki}[Wiki]
@@ -1,12 +0,0 @@
[[aop-api]]
= Spring AOP APIs
:page-section-summary-toc: 1
The previous chapter described the Spring's support for AOP with @AspectJ and schema-based
aspect definitions. In this chapter, we discuss the lower-level Spring AOP APIs. For common
applications, we recommend the use of Spring AOP with AspectJ pointcuts as described in the
previous chapter.
@@ -1,592 +0,0 @@
[[aop-api-advice]]
= Advice API in Spring
Now we can examine how Spring AOP handles advice.
[[aop-api-advice-lifecycle]]
== Advice Lifecycles
Each advice is a Spring bean. An advice instance can be shared across all advised
objects or be unique to each advised object. This corresponds to per-class or
per-instance advice.
Per-class advice is used most often. It is appropriate for generic advice, such as
transaction advisors. These do not depend on the state of the proxied object or add new
state. They merely act on the method and arguments.
Per-instance advice is appropriate for introductions, to support mixins. In this case,
the advice adds state to the proxied object.
You can use a mix of shared and per-instance advice in the same AOP proxy.
[[aop-api-advice-types]]
== Advice Types in Spring
Spring provides several advice types and is extensible to support
arbitrary advice types. This section describes the basic concepts and standard advice types.
[[aop-api-advice-around]]
=== Interception Around Advice
The most fundamental advice type in Spring is interception around advice.
Spring is compliant with the AOP `Alliance` interface for around advice that uses method
interception. Classes that implement `MethodInterceptor` and that implement around advice should also implement the
following interface:
[source,java,indent=0,subs="verbatim,quotes"]
----
public interface MethodInterceptor extends Interceptor {
Object invoke(MethodInvocation invocation) throws Throwable;
}
----
The `MethodInvocation` argument to the `invoke()` method exposes the method being
invoked, the target join point, the AOP proxy, and the arguments to the method. The
`invoke()` method should return the invocation's result: the return value of the join
point.
The following example shows a simple `MethodInterceptor` implementation:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class DebugInterceptor implements MethodInterceptor {
public Object invoke(MethodInvocation invocation) throws Throwable {
System.out.println("Before: invocation=[" + invocation + "]");
Object rval = invocation.proceed();
System.out.println("Invocation returned");
return rval;
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class DebugInterceptor : MethodInterceptor {
override fun invoke(invocation: MethodInvocation): Any {
println("Before: invocation=[$invocation]")
val rval = invocation.proceed()
println("Invocation returned")
return rval
}
}
----
======
Note the call to the `proceed()` method of `MethodInvocation`. This proceeds down the
interceptor chain towards the join point. Most interceptors invoke this method and
return its return value. However, a `MethodInterceptor`, like any around advice, can
return a different value or throw an exception rather than invoke the proceed method.
However, you do not want to do this without good reason.
NOTE: `MethodInterceptor` implementations offer interoperability with other AOP Alliance-compliant AOP
implementations. The other advice types discussed in the remainder of this section
implement common AOP concepts but in a Spring-specific way. While there is an advantage
in using the most specific advice type, stick with `MethodInterceptor` around advice if
you are likely to want to run the aspect in another AOP framework. Note that pointcuts
are not currently interoperable between frameworks, and the AOP Alliance does not
currently define pointcut interfaces.
[[aop-api-advice-before]]
=== Before Advice
A simpler advice type is a before advice. This does not need a `MethodInvocation`
object, since it is called only before entering the method.
The main advantage of a before advice is that there is no need to invoke the `proceed()`
method and, therefore, no possibility of inadvertently failing to proceed down the
interceptor chain.
The following listing shows the `MethodBeforeAdvice` interface:
[source,java,indent=0,subs="verbatim,quotes"]
----
public interface MethodBeforeAdvice extends BeforeAdvice {
void before(Method m, Object[] args, Object target) throws Throwable;
}
----
(Spring's API design would allow for
field before advice, although the usual objects apply to field interception and it is
unlikely for Spring to ever implement it.)
Note that the return type is `void`. Before advice can insert custom behavior before the join
point runs but cannot change the return value. If a before advice throws an
exception, it stops further execution of the interceptor chain. The exception
propagates back up the interceptor chain. If it is unchecked or on the signature of
the invoked method, it is passed directly to the client. Otherwise, it is
wrapped in an unchecked exception by the AOP proxy.
The following example shows a before advice in Spring, which counts all method invocations:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class CountingBeforeAdvice implements MethodBeforeAdvice {
private int count;
public void before(Method m, Object[] args, Object target) throws Throwable {
++count;
}
public int getCount() {
return count;
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class CountingBeforeAdvice : MethodBeforeAdvice {
var count: Int = 0
override fun before(m: Method, args: Array<Any>, target: Any?) {
++count
}
}
----
======
TIP: Before advice can be used with any pointcut.
[[aop-api-advice-throws]]
=== Throws Advice
Throws advice is invoked after the return of the join point if the join point threw
an exception. Spring offers typed throws advice. Note that this means that the
`org.springframework.aop.ThrowsAdvice` interface does not contain any methods. It is a
tag interface identifying that the given object implements one or more typed throws
advice methods. These should be in the following form:
[source,java,indent=0,subs="verbatim,quotes"]
----
afterThrowing([Method, args, target], subclassOfThrowable)
----
Only the last argument is required. The method signatures may have either one or four
arguments, depending on whether the advice method is interested in the method and
arguments. The next two listing show classes that are examples of throws advice.
The following advice is invoked if a `RemoteException` is thrown (including from subclasses):
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class RemoteThrowsAdvice implements ThrowsAdvice {
public void afterThrowing(RemoteException ex) throws Throwable {
// Do something with remote exception
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class RemoteThrowsAdvice : ThrowsAdvice {
fun afterThrowing(ex: RemoteException) {
// Do something with remote exception
}
}
----
======
Unlike the preceding
advice, the next example declares four arguments, so that it has access to the invoked method, method
arguments, and target object. The following advice is invoked if a `ServletException` is thrown:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class ServletThrowsAdviceWithArguments implements ThrowsAdvice {
public void afterThrowing(Method m, Object[] args, Object target, ServletException ex) {
// Do something with all arguments
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class ServletThrowsAdviceWithArguments : ThrowsAdvice {
fun afterThrowing(m: Method, args: Array<Any>, target: Any, ex: ServletException) {
// Do something with all arguments
}
}
----
======
The final example illustrates how these two methods could be used in a single class
that handles both `RemoteException` and `ServletException`. Any number of throws advice
methods can be combined in a single class. The following listing shows the final example:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public static class CombinedThrowsAdvice implements ThrowsAdvice {
public void afterThrowing(RemoteException ex) throws Throwable {
// Do something with remote exception
}
public void afterThrowing(Method m, Object[] args, Object target, ServletException ex) {
// Do something with all arguments
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class CombinedThrowsAdvice : ThrowsAdvice {
fun afterThrowing(ex: RemoteException) {
// Do something with remote exception
}
fun afterThrowing(m: Method, args: Array<Any>, target: Any, ex: ServletException) {
// Do something with all arguments
}
}
----
======
NOTE: If a throws-advice method throws an exception itself, it overrides the
original exception (that is, it changes the exception thrown to the user). The overriding
exception is typically a RuntimeException, which is compatible with any method
signature. However, if a throws-advice method throws a checked exception, it must
match the declared exceptions of the target method and is, hence, to some degree
coupled to specific target method signatures. _Do not throw an undeclared checked
exception that is incompatible with the target method's signature!_
TIP: Throws advice can be used with any pointcut.
[[aop-api-advice-after-returning]]
=== After Returning Advice
An after returning advice in Spring must implement the
`org.springframework.aop.AfterReturningAdvice` interface, which the following listing shows:
[source,java,indent=0,subs="verbatim,quotes"]
----
public interface AfterReturningAdvice extends Advice {
void afterReturning(Object returnValue, Method m, Object[] args, Object target)
throws Throwable;
}
----
An after returning advice has access to the return value (which it cannot modify),
the invoked method, the method's arguments, and the target.
The following after returning advice counts all successful method invocations that have
not thrown exceptions:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class CountingAfterReturningAdvice implements AfterReturningAdvice {
private int count;
public void afterReturning(Object returnValue, Method m, Object[] args, Object target)
throws Throwable {
++count;
}
public int getCount() {
return count;
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class CountingAfterReturningAdvice : AfterReturningAdvice {
var count: Int = 0
private set
override fun afterReturning(returnValue: Any?, m: Method, args: Array<Any>, target: Any?) {
++count
}
}
----
======
This advice does not change the execution path. If it throws an exception, it is
thrown up the interceptor chain instead of the return value.
TIP: After returning advice can be used with any pointcut.
[[aop-api-advice-introduction]]
=== Introduction Advice
Spring treats introduction advice as a special kind of interception advice.
Introduction requires an `IntroductionAdvisor` and an `IntroductionInterceptor` that
implement the following interface:
[source,java,indent=0,subs="verbatim,quotes"]
----
public interface IntroductionInterceptor extends MethodInterceptor {
boolean implementsInterface(Class intf);
}
----
The `invoke()` method inherited from the AOP Alliance `MethodInterceptor` interface must
implement the introduction. That is, if the invoked method is on an introduced
interface, the introduction interceptor is responsible for handling the method call -- it
cannot invoke `proceed()`.
Introduction advice cannot be used with any pointcut, as it applies only at the class,
rather than the method, level. You can only use introduction advice with the
`IntroductionAdvisor`, which has the following methods:
[source,java,indent=0,subs="verbatim,quotes"]
----
public interface IntroductionAdvisor extends Advisor, IntroductionInfo {
ClassFilter getClassFilter();
void validateInterfaces() throws IllegalArgumentException;
}
public interface IntroductionInfo {
Class<?>[] getInterfaces();
}
----
There is no `MethodMatcher` and, hence, no `Pointcut` associated with introduction
advice. Only class filtering is logical.
The `getInterfaces()` method returns the interfaces introduced by this advisor.
The `validateInterfaces()` method is used internally to see whether or not the
introduced interfaces can be implemented by the configured `IntroductionInterceptor`.
Consider an example from the Spring test suite and suppose we want to
introduce the following interface to one or more objects:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public interface Lockable {
void lock();
void unlock();
boolean locked();
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
interface Lockable {
fun lock()
fun unlock()
fun locked(): Boolean
}
----
======
This illustrates a mixin. We want to be able to cast advised objects to `Lockable`,
whatever their type and call lock and unlock methods. If we call the `lock()` method, we
want all setter methods to throw a `LockedException`. Thus, we can add an aspect that
provides the ability to make objects immutable without them having any knowledge of it:
a good example of AOP.
First, we need an `IntroductionInterceptor` that does the heavy lifting. In this
case, we extend the `org.springframework.aop.support.DelegatingIntroductionInterceptor`
convenience class. We could implement `IntroductionInterceptor` directly, but using
`DelegatingIntroductionInterceptor` is best for most cases.
The `DelegatingIntroductionInterceptor` is designed to delegate an introduction to an
actual implementation of the introduced interfaces, concealing the use of interception
to do so. You can set the delegate to any object using a constructor argument. The
default delegate (when the no-argument constructor is used) is `this`. Thus, in the next example,
the delegate is the `LockMixin` subclass of `DelegatingIntroductionInterceptor`.
Given a delegate (by default, itself), a `DelegatingIntroductionInterceptor` instance
looks for all interfaces implemented by the delegate (other than
`IntroductionInterceptor`) and supports introductions against any of them.
Subclasses such as `LockMixin` can call the `suppressInterface(Class intf)`
method to suppress interfaces that should not be exposed. However, no matter how many
interfaces an `IntroductionInterceptor` is prepared to support, the
`IntroductionAdvisor` used controls which interfaces are actually exposed. An
introduced interface conceals any implementation of the same interface by the target.
Thus, `LockMixin` extends `DelegatingIntroductionInterceptor` and implements `Lockable`
itself. The superclass automatically picks up that `Lockable` can be supported for
introduction, so we do not need to specify that. We could introduce any number of
interfaces in this way.
Note the use of the `locked` instance variable. This effectively adds additional state
to that held in the target object.
The following example shows the example `LockMixin` class:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class LockMixin extends DelegatingIntroductionInterceptor implements Lockable {
private boolean locked;
public void lock() {
this.locked = true;
}
public void unlock() {
this.locked = false;
}
public boolean locked() {
return this.locked;
}
public Object invoke(MethodInvocation invocation) throws Throwable {
if (locked() && invocation.getMethod().getName().indexOf("set") == 0) {
throw new LockedException();
}
return super.invoke(invocation);
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class LockMixin : DelegatingIntroductionInterceptor(), Lockable {
private var locked: Boolean = false
fun lock() {
this.locked = true
}
fun unlock() {
this.locked = false
}
fun locked(): Boolean {
return this.locked
}
override fun invoke(invocation: MethodInvocation): Any? {
if (locked() && invocation.method.name.indexOf("set") == 0) {
throw LockedException()
}
return super.invoke(invocation)
}
}
----
======
Often, you need not override the `invoke()` method. The
`DelegatingIntroductionInterceptor` implementation (which calls the `delegate` method if
the method is introduced, otherwise proceeds towards the join point) usually
suffices. In the present case, we need to add a check: no setter method can be invoked
if in locked mode.
The required introduction only needs to hold a distinct
`LockMixin` instance and specify the introduced interfaces (in this case, only
`Lockable`). A more complex example might take a reference to the introduction
interceptor (which would be defined as a prototype). In this case, there is no
configuration relevant for a `LockMixin`, so we create it by using `new`.
The following example shows our `LockMixinAdvisor` class:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class LockMixinAdvisor extends DefaultIntroductionAdvisor {
public LockMixinAdvisor() {
super(new LockMixin(), Lockable.class);
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class LockMixinAdvisor : DefaultIntroductionAdvisor(LockMixin(), Lockable::class.java)
----
======
We can apply this advisor very simply, because it requires no configuration. (However, it
is impossible to use an `IntroductionInterceptor` without an
`IntroductionAdvisor`.) As usual with introductions, the advisor must be per-instance,
as it is stateful. We need a different instance of `LockMixinAdvisor`, and hence
`LockMixin`, for each advised object. The advisor comprises part of the advised object's
state.
We can apply this advisor programmatically by using the `Advised.addAdvisor()` method or
(the recommended way) in XML configuration, as any other advisor. All proxy creation
choices discussed below, including "`auto proxy creators,`" correctly handle introductions
and stateful mixins.
@@ -1,148 +0,0 @@
[[aop-api-advised]]
= Manipulating Advised Objects
However you create AOP proxies, you can manipulate them BY using the
`org.springframework.aop.framework.Advised` interface. Any AOP proxy can be cast to this
interface, no matter which other interfaces it implements. This interface includes the
following methods:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
Advisor[] getAdvisors();
void addAdvice(Advice advice) throws AopConfigException;
void addAdvice(int pos, Advice advice) throws AopConfigException;
void addAdvisor(Advisor advisor) throws AopConfigException;
void addAdvisor(int pos, Advisor advisor) throws AopConfigException;
int indexOf(Advisor advisor);
boolean removeAdvisor(Advisor advisor) throws AopConfigException;
void removeAdvisor(int index) throws AopConfigException;
boolean replaceAdvisor(Advisor a, Advisor b) throws AopConfigException;
boolean isFrozen();
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
fun getAdvisors(): Array<Advisor>
@Throws(AopConfigException::class)
fun addAdvice(advice: Advice)
@Throws(AopConfigException::class)
fun addAdvice(pos: Int, advice: Advice)
@Throws(AopConfigException::class)
fun addAdvisor(advisor: Advisor)
@Throws(AopConfigException::class)
fun addAdvisor(pos: Int, advisor: Advisor)
fun indexOf(advisor: Advisor): Int
@Throws(AopConfigException::class)
fun removeAdvisor(advisor: Advisor): Boolean
@Throws(AopConfigException::class)
fun removeAdvisor(index: Int)
@Throws(AopConfigException::class)
fun replaceAdvisor(a: Advisor, b: Advisor): Boolean
fun isFrozen(): Boolean
----
======
The `getAdvisors()` method returns an `Advisor` for every advisor, interceptor, or
other advice type that has been added to the factory. If you added an `Advisor`, the
returned advisor at this index is the object that you added. If you added an
interceptor or other advice type, Spring wrapped this in an advisor with a
pointcut that always returns `true`. Thus, if you added a `MethodInterceptor`, the advisor
returned for this index is a `DefaultPointcutAdvisor` that returns your
`MethodInterceptor` and a pointcut that matches all classes and methods.
The `addAdvisor()` methods can be used to add any `Advisor`. Usually, the advisor holding
pointcut and advice is the generic `DefaultPointcutAdvisor`, which you can use with
any advice or pointcut (but not for introductions).
By default, it is possible to add or remove advisors or interceptors even once a proxy
has been created. The only restriction is that it is impossible to add or remove an
introduction advisor, as existing proxies from the factory do not show the interface
change. (You can obtain a new proxy from the factory to avoid this problem.)
The following example shows casting an AOP proxy to the `Advised` interface and examining and
manipulating its advice:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
Advised advised = (Advised) myObject;
Advisor[] advisors = advised.getAdvisors();
int oldAdvisorCount = advisors.length;
System.out.println(oldAdvisorCount + " advisors");
// Add an advice like an interceptor without a pointcut
// Will match all proxied methods
// Can use for interceptors, before, after returning or throws advice
advised.addAdvice(new DebugInterceptor());
// Add selective advice using a pointcut
advised.addAdvisor(new DefaultPointcutAdvisor(mySpecialPointcut, myAdvice));
assertEquals("Added two advisors", oldAdvisorCount + 2, advised.getAdvisors().length);
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
val advised = myObject as Advised
val advisors = advised.advisors
val oldAdvisorCount = advisors.size
println("$oldAdvisorCount advisors")
// Add an advice like an interceptor without a pointcut
// Will match all proxied methods
// Can use for interceptors, before, after returning or throws advice
advised.addAdvice(DebugInterceptor())
// Add selective advice using a pointcut
advised.addAdvisor(DefaultPointcutAdvisor(mySpecialPointcut, myAdvice))
assertEquals("Added two advisors", oldAdvisorCount + 2, advised.advisors.size)
----
======
NOTE: It is questionable whether it is advisable (no pun intended) to modify advice on a
business object in production, although there are, no doubt, legitimate usage cases.
However, it can be very useful in development (for example, in tests). We have sometimes
found it very useful to be able to add test code in the form of an interceptor or other
advice, getting inside a method invocation that we want to test. (For example, the advice can
get inside a transaction created for that method, perhaps to run SQL to check that
a database was correctly updated, before marking the transaction for roll back.)
Depending on how you created the proxy, you can usually set a `frozen` flag. In that
case, the `Advised` `isFrozen()` method returns `true`, and any attempts to modify
advice through addition or removal results in an `AopConfigException`. The ability
to freeze the state of an advised object is useful in some cases (for example, to
prevent calling code removing a security interceptor).
@@ -1,20 +0,0 @@
[[aop-api-advisor]]
= The Advisor API in Spring
:page-section-summary-toc: 1
In Spring, an Advisor is an aspect that contains only a single advice object associated
with a pointcut expression.
Apart from the special case of introductions, any advisor can be used with any advice.
`org.springframework.aop.support.DefaultPointcutAdvisor` is the most commonly used
advisor class. It can be used with a `MethodInterceptor`, `BeforeAdvice`, or
`ThrowsAdvice`.
It is possible to mix advisor and advice types in Spring in the same AOP proxy. For
example, you could use an interception around advice, throws advice, and before advice in
one proxy configuration. Spring automatically creates the necessary interceptor
chain.
@@ -1,131 +0,0 @@
[[aop-autoproxy]]
= Using the "auto-proxy" facility
So far, we have considered explicit creation of AOP proxies by using a `ProxyFactoryBean` or
similar factory bean.
Spring also lets us use "`auto-proxy`" bean definitions, which can automatically
proxy selected bean definitions. This is built on Spring's "`bean post processor`"
infrastructure, which enables modification of any bean definition as the container loads.
In this model, you set up some special bean definitions in your XML bean definition file
to configure the auto-proxy infrastructure. This lets you declare the targets
eligible for auto-proxying. You need not use `ProxyFactoryBean`.
There are two ways to do this:
* By using an auto-proxy creator that refers to specific beans in the current context.
* A special case of auto-proxy creation that deserves to be considered separately:
auto-proxy creation driven by source-level metadata attributes.
[[aop-autoproxy-choices]]
== Auto-proxy Bean Definitions
This section covers the auto-proxy creators provided by the
`org.springframework.aop.framework.autoproxy` package.
[[aop-api-autoproxy]]
=== `BeanNameAutoProxyCreator`
The `BeanNameAutoProxyCreator` class is a `BeanPostProcessor` that automatically creates
AOP proxies for beans with names that match literal values or wildcards. The following
example shows how to create a `BeanNameAutoProxyCreator` bean:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean class="org.springframework.aop.framework.autoproxy.BeanNameAutoProxyCreator">
<property name="beanNames" value="jdk*,onlyJdk"/>
<property name="interceptorNames">
<list>
<value>myInterceptor</value>
</list>
</property>
</bean>
----
As with `ProxyFactoryBean`, there is an `interceptorNames` property rather than a list
of interceptors, to allow correct behavior for prototype advisors. Named "`interceptors`"
can be advisors or any advice type.
As with auto-proxying in general, the main point of using `BeanNameAutoProxyCreator` is
to apply the same configuration consistently to multiple objects, with minimal volume of
configuration. It is a popular choice for applying declarative transactions to multiple
objects.
Bean definitions whose names match, such as `jdkMyBean` and `onlyJdk` in the preceding
example, are plain old bean definitions with the target class. An AOP proxy is
automatically created by the `BeanNameAutoProxyCreator`. The same advice is applied
to all matching beans. Note that, if advisors are used (rather than the interceptor in
the preceding example), the pointcuts may apply differently to different beans.
[[aop-api-autoproxy-default]]
=== `DefaultAdvisorAutoProxyCreator`
A more general and extremely powerful auto-proxy creator is
`DefaultAdvisorAutoProxyCreator`. This automagically applies eligible advisors in the
current context, without the need to include specific bean names in the auto-proxy
advisor's bean definition. It offers the same merit of consistent configuration and
avoidance of duplication as `BeanNameAutoProxyCreator`.
Using this mechanism involves:
* Specifying a `DefaultAdvisorAutoProxyCreator` bean definition.
* Specifying any number of advisors in the same or related contexts. Note that these
must be advisors, not interceptors or other advice. This is necessary,
because there must be a pointcut to evaluate, to check the eligibility of each advice
to candidate bean definitions.
The `DefaultAdvisorAutoProxyCreator` automatically evaluates the pointcut contained
in each advisor, to see what (if any) advice it should apply to each business object
(such as `businessObject1` and `businessObject2` in the example).
This means that any number of advisors can be applied automatically to each business
object. If no pointcut in any of the advisors matches any method in a business object,
the object is not proxied. As bean definitions are added for new business objects,
they are automatically proxied if necessary.
Auto-proxying in general has the advantage of making it impossible for callers or
dependencies to obtain an un-advised object. Calling `getBean("businessObject1")` on this
`ApplicationContext` returns an AOP proxy, not the target business object. (The "`inner
bean`" idiom shown earlier also offers this benefit.)
The following example creates a `DefaultAdvisorAutoProxyCreator` bean and the other
elements discussed in this section:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean class="org.springframework.aop.framework.autoproxy.DefaultAdvisorAutoProxyCreator"/>
<bean class="org.springframework.transaction.interceptor.TransactionAttributeSourceAdvisor">
<property name="transactionInterceptor" ref="transactionInterceptor"/>
</bean>
<bean id="customAdvisor" class="com.mycompany.MyAdvisor"/>
<bean id="businessObject1" class="com.mycompany.BusinessObject1">
<!-- Properties omitted -->
</bean>
<bean id="businessObject2" class="com.mycompany.BusinessObject2"/>
----
The `DefaultAdvisorAutoProxyCreator` is very useful if you want to apply the same advice
consistently to many business objects. Once the infrastructure definitions are in place,
you can add new business objects without including specific proxy configuration.
You can also easily drop in additional aspects (for example, tracing or
performance monitoring aspects) with minimal change to configuration.
The `DefaultAdvisorAutoProxyCreator` offers support for filtering (by using a naming
convention so that only certain advisors are evaluated, which allows the use of multiple,
differently configured, AdvisorAutoProxyCreators in the same factory) and ordering.
Advisors can implement the `org.springframework.core.Ordered` interface to ensure
correct ordering if this is an issue. The `TransactionAttributeSourceAdvisor` used in the
preceding example has a configurable order value. The default setting is unordered.
@@ -1,71 +0,0 @@
[[aop-concise-proxy]]
= Concise Proxy Definitions
Especially when defining transactional proxies, you may end up with many similar proxy
definitions. The use of parent and child bean definitions, along with inner bean
definitions, can result in much cleaner and more concise proxy definitions.
First, we create a parent, template, bean definition for the proxy, as follows:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean id="txProxyTemplate" abstract="true"
class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean">
<property name="transactionManager" ref="transactionManager"/>
<property name="transactionAttributes">
<props>
<prop key="*">PROPAGATION_REQUIRED</prop>
</props>
</property>
</bean>
----
This is never instantiated itself, so it can actually be incomplete. Then, each proxy
that needs to be created is a child bean definition, which wraps the target of the
proxy as an inner bean definition, since the target is never used on its own anyway.
The following example shows such a child bean:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean id="myService" parent="txProxyTemplate">
<property name="target">
<bean class="org.springframework.samples.MyServiceImpl">
</bean>
</property>
</bean>
----
You can override properties from the parent template. In the following example,
we override the transaction propagation settings:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean id="mySpecialService" parent="txProxyTemplate">
<property name="target">
<bean class="org.springframework.samples.MySpecialServiceImpl">
</bean>
</property>
<property name="transactionAttributes">
<props>
<prop key="get*">PROPAGATION_REQUIRED,readOnly</prop>
<prop key="find*">PROPAGATION_REQUIRED,readOnly</prop>
<prop key="load*">PROPAGATION_REQUIRED,readOnly</prop>
<prop key="store*">PROPAGATION_REQUIRED</prop>
</props>
</property>
</bean>
----
Note that in the parent bean example, we explicitly marked the parent bean definition as
being abstract by setting the `abstract` attribute to `true`, as described
xref:core/beans/child-bean-definitions.adoc[previously], so that it may not actually ever be
instantiated. Application contexts (but not simple bean factories), by default,
pre-instantiate all singletons. Therefore, it is important (at least for singleton beans)
that, if you have a (parent) bean definition that you intend to use only as a template,
and this definition specifies a class, you must make sure to set the `abstract`
attribute to `true`. Otherwise, the application context actually tries to
pre-instantiate it.
@@ -1,16 +0,0 @@
[[aop-extensibility]]
= Defining New Advice Types
:page-section-summary-toc: 1
Spring AOP is designed to be extensible. While the interception implementation strategy
is presently used internally, it is possible to support arbitrary advice types in
addition to the interception around advice, before, throws advice, and
after returning advice.
The `org.springframework.aop.framework.adapter` package is an SPI package that lets
support for new custom advice types be added without changing the core framework.
The only constraint on a custom `Advice` type is that it must implement the
`org.aopalliance.aop.Advice` marker interface.
See the {spring-framework-api}/aop/framework/adapter/package-summary.html[`org.springframework.aop.framework.adapter`]
javadoc for further information.
@@ -1,329 +0,0 @@
[[aop-pfb]]
= Using the `ProxyFactoryBean` to Create AOP Proxies
If you use the Spring IoC container (an `ApplicationContext` or `BeanFactory`) for your
business objects (and you should be!), you want to use one of Spring's AOP
`FactoryBean` implementations. (Remember that a factory bean introduces a layer of indirection, letting
it create objects of a different type.)
NOTE: The Spring AOP support also uses factory beans under the covers.
The basic way to create an AOP proxy in Spring is to use the
`org.springframework.aop.framework.ProxyFactoryBean`. This gives complete control over
the pointcuts, any advice that applies, and their ordering. However, there are simpler
options that are preferable if you do not need such control.
[[aop-pfb-1]]
== Basics
The `ProxyFactoryBean`, like other Spring `FactoryBean` implementations, introduces a
level of indirection. If you define a `ProxyFactoryBean` named `foo`, objects that
reference `foo` do not see the `ProxyFactoryBean` instance itself but an object
created by the implementation of the `getObject()` method in the `ProxyFactoryBean` . This
method creates an AOP proxy that wraps a target object.
One of the most important benefits of using a `ProxyFactoryBean` or another IoC-aware
class to create AOP proxies is that advice and pointcuts can also be
managed by IoC. This is a powerful feature, enabling certain approaches that are hard to
achieve with other AOP frameworks. For example, an advice may itself reference
application objects (besides the target, which should be available in any AOP
framework), benefiting from all the pluggability provided by Dependency Injection.
[[aop-pfb-2]]
== JavaBean Properties
In common with most `FactoryBean` implementations provided with Spring, the
`ProxyFactoryBean` class is itself a JavaBean. Its properties are used to:
* Specify the target you want to proxy.
* Specify whether to use CGLIB (described later and see also xref:core/aop-api/pfb.adoc#aop-pfb-proxy-types[JDK- and CGLIB-based proxies]).
Some key properties are inherited from `org.springframework.aop.framework.ProxyConfig`
(the superclass for all AOP proxy factories in Spring). These key properties include
the following:
* `proxyTargetClass`: `true` if the target class is to be proxied, rather than the
target class's interfaces. If this property value is set to `true`, then CGLIB proxies
are created (but see also xref:core/aop-api/pfb.adoc#aop-pfb-proxy-types[JDK- and CGLIB-based proxies]).
* `optimize`: Controls whether or not aggressive optimizations are applied to proxies
created through CGLIB. You should not blithely use this setting unless you fully
understand how the relevant AOP proxy handles optimization. This is currently used
only for CGLIB proxies. It has no effect with JDK dynamic proxies.
* `frozen`: If a proxy configuration is `frozen`, changes to the configuration are
no longer allowed. This is useful both as a slight optimization and for those cases
when you do not want callers to be able to manipulate the proxy (through the `Advised`
interface) after the proxy has been created. The default value of this property is
`false`, so changes (such as adding additional advice) are allowed.
* `exposeProxy`: Determines whether or not the current proxy should be exposed in a
`ThreadLocal` so that it can be accessed by the target. If a target needs to obtain
the proxy and the `exposeProxy` property is set to `true`, the target can use the
`AopContext.currentProxy()` method.
Other properties specific to `ProxyFactoryBean` include the following:
* `proxyInterfaces`: An array of `String` interface names. If this is not supplied, a CGLIB
proxy for the target class is used (but see also xref:core/aop-api/pfb.adoc#aop-pfb-proxy-types[JDK- and CGLIB-based proxies]).
* `interceptorNames`: A `String` array of `Advisor`, interceptor, or other advice names to
apply. Ordering is significant, on a first come-first served basis. That is to say
that the first interceptor in the list is the first to be able to intercept the
invocation.
+
The names are bean names in the current factory, including bean names from ancestor
factories. You cannot mention bean references here, since doing so results in the
`ProxyFactoryBean` ignoring the singleton setting of the advice.
+
You can append an interceptor name with an asterisk (`*`). Doing so results in the
application of all advisor beans with names that start with the part before the asterisk
to be applied. You can find an example of using this feature in xref:core/aop-api/pfb.adoc#aop-global-advisors[Using "`Global`" Advisors].
* singleton: Whether or not the factory should return a single object, no matter how
often the `getObject()` method is called. Several `FactoryBean` implementations offer
such a method. The default value is `true`. If you want to use stateful advice - for
example, for stateful mixins - use prototype advice along with a singleton value of
`false`.
[[aop-pfb-proxy-types]]
== JDK- and CGLIB-based proxies
This section serves as the definitive documentation on how the `ProxyFactoryBean`
chooses to create either a JDK-based proxy or a CGLIB-based proxy for a particular target
object (which is to be proxied).
NOTE: The behavior of the `ProxyFactoryBean` with regard to creating JDK- or CGLIB-based
proxies changed between versions 1.2.x and 2.0 of Spring. The `ProxyFactoryBean` now
exhibits similar semantics with regard to auto-detecting interfaces as those of the
`TransactionProxyFactoryBean` class.
If the class of a target object that is to be proxied (hereafter simply referred to as
the target class) does not implement any interfaces, a CGLIB-based proxy is
created. This is the easiest scenario, because JDK proxies are interface-based, and no
interfaces means JDK proxying is not even possible. You can plug in the target bean
and specify the list of interceptors by setting the `interceptorNames` property. Note that a
CGLIB-based proxy is created even if the `proxyTargetClass` property of the
`ProxyFactoryBean` has been set to `false`. (Doing so makes no sense and is best
removed from the bean definition, because it is, at best, redundant, and, at worst
confusing.)
If the target class implements one (or more) interfaces, the type of proxy that is
created depends on the configuration of the `ProxyFactoryBean`.
If the `proxyTargetClass` property of the `ProxyFactoryBean` has been set to `true`,
a CGLIB-based proxy is created. This makes sense and is in keeping with the
principle of least surprise. Even if the `proxyInterfaces` property of the
`ProxyFactoryBean` has been set to one or more fully qualified interface names, the fact
that the `proxyTargetClass` property is set to `true` causes CGLIB-based
proxying to be in effect.
If the `proxyInterfaces` property of the `ProxyFactoryBean` has been set to one or more
fully qualified interface names, a JDK-based proxy is created. The created
proxy implements all of the interfaces that were specified in the `proxyInterfaces`
property. If the target class happens to implement a whole lot more interfaces than
those specified in the `proxyInterfaces` property, that is all well and good, but those
additional interfaces are not implemented by the returned proxy.
If the `proxyInterfaces` property of the `ProxyFactoryBean` has not been set, but
the target class does implement one (or more) interfaces, the
`ProxyFactoryBean` auto-detects the fact that the target class does actually
implement at least one interface, and a JDK-based proxy is created. The interfaces
that are actually proxied are all of the interfaces that the target class
implements. In effect, this is the same as supplying a list of each and every
interface that the target class implements to the `proxyInterfaces` property. However,
it is significantly less work and less prone to typographical errors.
[[aop-api-proxying-intf]]
== Proxying Interfaces
Consider a simple example of `ProxyFactoryBean` in action. This example involves:
* A target bean that is proxied. This is the `personTarget` bean definition in
the example.
* An `Advisor` and an `Interceptor` used to provide advice.
* An AOP proxy bean definition to specify the target object (the `personTarget` bean),
the interfaces to proxy, and the advice to apply.
The following listing shows the example:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean id="personTarget" class="com.mycompany.PersonImpl">
<property name="name" value="Tony"/>
<property name="age" value="51"/>
</bean>
<bean id="myAdvisor" class="com.mycompany.MyAdvisor">
<property name="someProperty" value="Custom string property value"/>
</bean>
<bean id="debugInterceptor" class="org.springframework.aop.interceptor.DebugInterceptor">
</bean>
<bean id="person"
class="org.springframework.aop.framework.ProxyFactoryBean">
<property name="proxyInterfaces" value="com.mycompany.Person"/>
<property name="target" ref="personTarget"/>
<property name="interceptorNames">
<list>
<value>myAdvisor</value>
<value>debugInterceptor</value>
</list>
</property>
</bean>
----
Note that the `interceptorNames` property takes a list of `String`, which holds the bean names of the
interceptors or advisors in the current factory. You can use advisors, interceptors, before, after
returning, and throws advice objects. The ordering of advisors is significant.
NOTE: You might be wondering why the list does not hold bean references. The reason for this is
that, if the singleton property of the `ProxyFactoryBean` is set to `false`, it must be able to
return independent proxy instances. If any of the advisors is itself a prototype, an
independent instance would need to be returned, so it is necessary to be able to obtain
an instance of the prototype from the factory. Holding a reference is not sufficient.
The `person` bean definition shown earlier can be used in place of a `Person` implementation, as
follows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
Person person = (Person) factory.getBean("person");
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
val person = factory.getBean("person") as Person;
----
======
Other beans in the same IoC context can express a strongly typed dependency on it, as
with an ordinary Java object. The following example shows how to do so:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean id="personUser" class="com.mycompany.PersonUser">
<property name="person"><ref bean="person"/></property>
</bean>
----
The `PersonUser` class in this example exposes a property of type `Person`. As far as
it is concerned, the AOP proxy can be used transparently in place of a "`real`" person
implementation. However, its class would be a dynamic proxy class. It would be possible
to cast it to the `Advised` interface (discussed later).
You can conceal the distinction between target and proxy by using an anonymous
inner bean. Only the `ProxyFactoryBean` definition is different. The
advice is included only for completeness. The following example shows how to use an
anonymous inner bean:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean id="myAdvisor" class="com.mycompany.MyAdvisor">
<property name="someProperty" value="Custom string property value"/>
</bean>
<bean id="debugInterceptor" class="org.springframework.aop.interceptor.DebugInterceptor"/>
<bean id="person" class="org.springframework.aop.framework.ProxyFactoryBean">
<property name="proxyInterfaces" value="com.mycompany.Person"/>
<!-- Use inner bean, not local reference to target -->
<property name="target">
<bean class="com.mycompany.PersonImpl">
<property name="name" value="Tony"/>
<property name="age" value="51"/>
</bean>
</property>
<property name="interceptorNames">
<list>
<value>myAdvisor</value>
<value>debugInterceptor</value>
</list>
</property>
</bean>
----
Using an anonymous inner bean has the advantage that there is only one object of type `Person`. This is useful if we want
to prevent users of the application context from obtaining a reference to the un-advised
object or need to avoid any ambiguity with Spring IoC autowiring. There is also,
arguably, an advantage in that the `ProxyFactoryBean` definition is self-contained.
However, there are times when being able to obtain the un-advised target from the
factory might actually be an advantage (for example, in certain test scenarios).
[[aop-api-proxying-class]]
== Proxying Classes
What if you need to proxy a class, rather than one or more interfaces?
Imagine that in our earlier example, there was no `Person` interface. We needed to advise
a class called `Person` that did not implement any business interface. In this case, you
can configure Spring to use CGLIB proxying rather than dynamic proxies. To do so, set the
`proxyTargetClass` property on the `ProxyFactoryBean` shown earlier to `true`. While it is best to
program to interfaces rather than classes, the ability to advise classes that do not
implement interfaces can be useful when working with legacy code. (In general, Spring
is not prescriptive. While it makes it easy to apply good practices, it avoids forcing a
particular approach.)
If you want to, you can force the use of CGLIB in any case, even if you do have
interfaces.
CGLIB proxying works by generating a subclass of the target class at runtime. Spring
configures this generated subclass to delegate method calls to the original target. The
subclass is used to implement the Decorator pattern, weaving in the advice.
CGLIB proxying should generally be transparent to users. However, there are some issues
to consider:
* `final` classes cannot be proxied, because they cannot be extended.
* `final` methods cannot be advised, because they cannot be overridden.
* `private` methods cannot be advised, because they cannot be overridden.
NOTE: There is no need to add CGLIB to your classpath. CGLIB is repackaged and included
in the `spring-core` JAR. In other words, CGLIB-based AOP works "out of the box", as do
JDK dynamic proxies.
There is little performance difference between CGLIB proxies and dynamic proxies.
Performance should not be a decisive consideration in this case.
[[aop-global-advisors]]
== Using "`Global`" Advisors
By appending an asterisk to an interceptor name, all advisors with bean names that match
the part before the asterisk are added to the advisor chain. This can come in handy
if you need to add a standard set of "`global`" advisors. The following example defines
two global advisors:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean id="proxy" class="org.springframework.aop.framework.ProxyFactoryBean">
<property name="target" ref="service"/>
<property name="interceptorNames">
<list>
<value>global*</value>
</list>
</property>
</bean>
<bean id="global_debug" class="org.springframework.aop.interceptor.DebugInterceptor"/>
<bean id="global_performance" class="org.springframework.aop.interceptor.PerformanceMonitorInterceptor"/>
----
@@ -1,256 +0,0 @@
[[aop-api-pointcuts]]
= Pointcut API in Spring
This section describes how Spring handles the crucial pointcut concept.
[[aop-api-concepts]]
== Concepts
Spring's pointcut model enables pointcut reuse independent of advice types. You can
target different advice with the same pointcut.
The `org.springframework.aop.Pointcut` interface is the central interface, used to
target advice to particular classes and methods. The complete interface follows:
[source,java,indent=0,subs="verbatim,quotes"]
----
public interface Pointcut {
ClassFilter getClassFilter();
MethodMatcher getMethodMatcher();
}
----
Splitting the `Pointcut` interface into two parts allows reuse of class and method
matching parts and fine-grained composition operations (such as performing a "`union`"
with another method matcher).
The `ClassFilter` interface is used to restrict the pointcut to a given set of target
classes. If the `matches()` method always returns true, all target classes are
matched. The following listing shows the `ClassFilter` interface definition:
[source,java,indent=0,subs="verbatim,quotes"]
----
public interface ClassFilter {
boolean matches(Class clazz);
}
----
The `MethodMatcher` interface is normally more important. The complete interface follows:
[source,java,indent=0,subs="verbatim,quotes"]
----
public interface MethodMatcher {
boolean matches(Method m, Class<?> targetClass);
boolean isRuntime();
boolean matches(Method m, Class<?> targetClass, Object... args);
}
----
The `matches(Method, Class)` method is used to test whether this pointcut ever
matches a given method on a target class. This evaluation can be performed when an AOP
proxy is created to avoid the need for a test on every method invocation. If the
two-argument `matches` method returns `true` for a given method, and the `isRuntime()`
method for the MethodMatcher returns `true`, the three-argument matches method is
invoked on every method invocation. This lets a pointcut look at the arguments passed
to the method invocation immediately before the target advice starts.
Most `MethodMatcher` implementations are static, meaning that their `isRuntime()` method
returns `false`. In this case, the three-argument `matches` method is never invoked.
TIP: If possible, try to make pointcuts static, allowing the AOP framework to cache the
results of pointcut evaluation when an AOP proxy is created.
[[aop-api-pointcut-ops]]
== Operations on Pointcuts
Spring supports operations (notably, union and intersection) on pointcuts.
Union means the methods that either pointcut matches.
Intersection means the methods that both pointcuts match.
Union is usually more useful.
You can compose pointcuts by using the static methods in the
`org.springframework.aop.support.Pointcuts` class or by using the
`ComposablePointcut` class in the same package. However, using AspectJ pointcut
expressions is usually a simpler approach.
[[aop-api-pointcuts-aspectj]]
== AspectJ Expression Pointcuts
Since 2.0, the most important type of pointcut used by Spring is
`org.springframework.aop.aspectj.AspectJExpressionPointcut`. This is a pointcut that
uses an AspectJ-supplied library to parse an AspectJ pointcut expression string.
See the xref:core/aop.adoc[previous chapter] for a discussion of supported AspectJ pointcut primitives.
[[aop-api-pointcuts-impls]]
== Convenience Pointcut Implementations
Spring provides several convenient pointcut implementations. You can use some of them
directly; others are intended to be subclassed in application-specific pointcuts.
[[aop-api-pointcuts-static]]
=== Static Pointcuts
Static pointcuts are based on the method and the target class and cannot take into account
the method's arguments. Static pointcuts suffice -- and are best -- for most usages.
Spring can evaluate a static pointcut only once, when a method is first invoked.
After that, there is no need to evaluate the pointcut again with each method invocation.
The rest of this section describes some of the static pointcut implementations that are
included with Spring.
[[aop-api-pointcuts-regex]]
==== Regular Expression Pointcuts
One obvious way to specify static pointcuts is regular expressions. Several AOP
frameworks besides Spring make this possible.
`org.springframework.aop.support.JdkRegexpMethodPointcut` is a generic regular
expression pointcut that uses the regular expression support in the JDK.
With the `JdkRegexpMethodPointcut` class, you can provide a list of pattern strings.
If any of these is a match, the pointcut evaluates to `true`. (As a consequence,
the resulting pointcut is effectively the union of the specified patterns.)
The following example shows how to use `JdkRegexpMethodPointcut`:
[source,xml,indent=0,subs="verbatim"]
----
<bean id="settersAndAbsquatulatePointcut"
class="org.springframework.aop.support.JdkRegexpMethodPointcut">
<property name="patterns">
<list>
<value>.*set.*</value>
<value>.*absquatulate</value>
</list>
</property>
</bean>
----
Spring provides a convenience class named `RegexpMethodPointcutAdvisor`, which lets us
also reference an `Advice` (remember that an `Advice` can be an interceptor, before advice,
throws advice, and others). Behind the scenes, Spring uses a `JdkRegexpMethodPointcut`.
Using `RegexpMethodPointcutAdvisor` simplifies wiring, as the one bean encapsulates both
pointcut and advice, as the following example shows:
[source,xml,indent=0,subs="verbatim"]
----
<bean id="settersAndAbsquatulateAdvisor"
class="org.springframework.aop.support.RegexpMethodPointcutAdvisor">
<property name="advice">
<ref bean="beanNameOfAopAllianceInterceptor"/>
</property>
<property name="patterns">
<list>
<value>.*set.*</value>
<value>.*absquatulate</value>
</list>
</property>
</bean>
----
You can use `RegexpMethodPointcutAdvisor` with any `Advice` type.
[[aop-api-pointcuts-attribute-driven]]
==== Attribute-driven Pointcuts
An important type of static pointcut is a metadata-driven pointcut. This uses the
values of metadata attributes (typically, source-level metadata).
[[aop-api-pointcuts-dynamic]]
=== Dynamic pointcuts
Dynamic pointcuts are costlier to evaluate than static pointcuts. They take into account
method arguments as well as static information. This means that they must be
evaluated with every method invocation and that the result cannot be cached, as arguments will
vary.
The main example is the `control flow` pointcut.
[[aop-api-pointcuts-cflow]]
==== Control Flow Pointcuts
Spring control flow pointcuts are conceptually similar to AspectJ `cflow` pointcuts,
although less powerful. (There is currently no way to specify that a pointcut runs
below a join point matched by another pointcut.) A control flow pointcut matches the
current call stack. For example, it might fire if the join point was invoked by a method
in the `com.mycompany.web` package or by the `SomeCaller` class. Control flow pointcuts
are specified by using the `org.springframework.aop.support.ControlFlowPointcut` class.
NOTE: Control flow pointcuts are significantly more expensive to evaluate at runtime than even
other dynamic pointcuts. In Java 1.4, the cost is about five times that of other dynamic
pointcuts.
[[aop-api-pointcuts-superclasses]]
== Pointcut Superclasses
Spring provides useful pointcut superclasses to help you to implement your own pointcuts.
Because static pointcuts are most useful, you should probably subclass
`StaticMethodMatcherPointcut`. This requires implementing only one
abstract method (although you can override other methods to customize behavior). The
following example shows how to subclass `StaticMethodMatcherPointcut`:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
class TestStaticPointcut extends StaticMethodMatcherPointcut {
public boolean matches(Method m, Class targetClass) {
// return true if custom criteria match
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class TestStaticPointcut : StaticMethodMatcherPointcut() {
override fun matches(method: Method, targetClass: Class<*>): Boolean {
// return true if custom criteria match
}
}
----
======
There are also superclasses for dynamic pointcuts.
You can use custom pointcuts with any advice type.
[[aop-api-pointcuts-custom]]
== Custom Pointcuts
Because pointcuts in Spring AOP are Java classes rather than language features (as in
AspectJ), you can declare custom pointcuts, whether static or dynamic. Custom
pointcuts in Spring can be arbitrarily complex. However, we recommend using the AspectJ pointcut
expression language, if you can.
NOTE: Later versions of Spring may offer support for "`semantic pointcuts`" as offered by JAC --
for example, "`all methods that change instance variables in the target object.`"
@@ -1,54 +0,0 @@
[[aop-prog]]
= Creating AOP Proxies Programmatically with the `ProxyFactory`
It is easy to create AOP proxies programmatically with Spring. This lets you use
Spring AOP without dependency on Spring IoC.
The interfaces implemented by the target object are
automatically proxied. The following listing shows creation of a proxy for a target object, with one
interceptor and one advisor:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
ProxyFactory factory = new ProxyFactory(myBusinessInterfaceImpl);
factory.addAdvice(myMethodInterceptor);
factory.addAdvisor(myAdvisor);
MyBusinessInterface tb = (MyBusinessInterface) factory.getProxy();
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
val factory = ProxyFactory(myBusinessInterfaceImpl)
factory.addAdvice(myMethodInterceptor)
factory.addAdvisor(myAdvisor)
val tb = factory.proxy as MyBusinessInterface
----
======
The first step is to construct an object of type
`org.springframework.aop.framework.ProxyFactory`. You can create this with a target
object, as in the preceding example, or specify the interfaces to be proxied in an alternate
constructor.
You can add advice (with interceptors as a specialized kind of advice), advisors, or both
and manipulate them for the life of the `ProxyFactory`. If you add an
`IntroductionInterceptionAroundAdvisor`, you can cause the proxy to implement additional
interfaces.
There are also convenience methods on `ProxyFactory` (inherited from `AdvisedSupport`)
that let you add other advice types, such as before and throws advice.
`AdvisedSupport` is the superclass of both `ProxyFactory` and `ProxyFactoryBean`.
TIP: Integrating AOP proxy creation with the IoC framework is best practice in most
applications. We recommend that you externalize configuration from Java code with AOP,
as you should in general.
@@ -1,232 +0,0 @@
[[aop-targetsource]]
= Using `TargetSource` Implementations
Spring offers the concept of a `TargetSource`, expressed in the
`org.springframework.aop.TargetSource` interface. This interface is responsible for
returning the "`target object`" that implements the join point. The `TargetSource`
implementation is asked for a target instance each time the AOP proxy handles a method
invocation.
Developers who use Spring AOP do not normally need to work directly with `TargetSource` implementations, but
this provides a powerful means of supporting pooling, hot swappable, and other
sophisticated targets. For example, a pooling `TargetSource` can return a different target
instance for each invocation, by using a pool to manage instances.
If you do not specify a `TargetSource`, a default implementation is used to wrap a
local object. The same target is returned for each invocation (as you would expect).
The rest of this section describes the standard target sources provided with Spring and how you can use them.
TIP: When using a custom target source, your target will usually need to be a prototype
rather than a singleton bean definition. This allows Spring to create a new target
instance when required.
[[aop-ts-swap]]
== Hot-swappable Target Sources
The `org.springframework.aop.target.HotSwappableTargetSource` exists to let the target
of an AOP proxy be switched while letting callers keep their references to it.
Changing the target source's target takes effect immediately. The
`HotSwappableTargetSource` is thread-safe.
You can change the target by using the `swap()` method on HotSwappableTargetSource, as the follow example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
HotSwappableTargetSource swapper = (HotSwappableTargetSource) beanFactory.getBean("swapper");
Object oldTarget = swapper.swap(newTarget);
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
val swapper = beanFactory.getBean("swapper") as HotSwappableTargetSource
val oldTarget = swapper.swap(newTarget)
----
======
The following example shows the required XML definitions:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean id="initialTarget" class="mycompany.OldTarget"/>
<bean id="swapper" class="org.springframework.aop.target.HotSwappableTargetSource">
<constructor-arg ref="initialTarget"/>
</bean>
<bean id="swappable" class="org.springframework.aop.framework.ProxyFactoryBean">
<property name="targetSource" ref="swapper"/>
</bean>
----
The preceding `swap()` call changes the target of the swappable bean. Clients that hold a
reference to that bean are unaware of the change but immediately start hitting
the new target.
Although this example does not add any advice (it is not necessary to add advice to
use a `TargetSource`), any `TargetSource` can be used in conjunction with
arbitrary advice.
[[aop-ts-pool]]
== Pooling Target Sources
Using a pooling target source provides a similar programming model to stateless session
EJBs, in which a pool of identical instances is maintained, with method invocations
going to free objects in the pool.
A crucial difference between Spring pooling and SLSB pooling is that Spring pooling can
be applied to any POJO. As with Spring in general, this service can be applied in a
non-invasive way.
Spring provides support for Commons Pool 2.2, which provides a
fairly efficient pooling implementation. You need the `commons-pool` Jar on your
application's classpath to use this feature. You can also subclass
`org.springframework.aop.target.AbstractPoolingTargetSource` to support any other
pooling API.
NOTE: Commons Pool 1.5+ is also supported but is deprecated as of Spring Framework 4.2.
The following listing shows an example configuration:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean id="businessObjectTarget" class="com.mycompany.MyBusinessObject"
scope="prototype">
... properties omitted
</bean>
<bean id="poolTargetSource" class="org.springframework.aop.target.CommonsPool2TargetSource">
<property name="targetBeanName" value="businessObjectTarget"/>
<property name="maxSize" value="25"/>
</bean>
<bean id="businessObject" class="org.springframework.aop.framework.ProxyFactoryBean">
<property name="targetSource" ref="poolTargetSource"/>
<property name="interceptorNames" value="myInterceptor"/>
</bean>
----
Note that the target object (`businessObjectTarget` in the preceding example) must be a
prototype. This lets the `PoolingTargetSource` implementation create new instances
of the target to grow the pool as necessary. See the {spring-framework-api}/aop/target/AbstractPoolingTargetSource.html[javadoc of
`AbstractPoolingTargetSource`] and the concrete subclass you wish to use for information
about its properties. `maxSize` is the most basic and is always guaranteed to be present.
In this case, `myInterceptor` is the name of an interceptor that would need to be
defined in the same IoC context. However, you need not specify interceptors to
use pooling. If you want only pooling and no other advice, do not set the
`interceptorNames` property at all.
You can configure Spring to be able to cast any pooled object to the
`org.springframework.aop.target.PoolingConfig` interface, which exposes information
about the configuration and current size of the pool through an introduction. You
need to define an advisor similar to the following:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean id="poolConfigAdvisor" class="org.springframework.beans.factory.config.MethodInvokingFactoryBean">
<property name="targetObject" ref="poolTargetSource"/>
<property name="targetMethod" value="getPoolingConfigMixin"/>
</bean>
----
This advisor is obtained by calling a convenience method on the
`AbstractPoolingTargetSource` class, hence the use of `MethodInvokingFactoryBean`. This
advisor's name (`poolConfigAdvisor`, here) must be in the list of interceptors names in
the `ProxyFactoryBean` that exposes the pooled object.
The cast is defined as follows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
PoolingConfig conf = (PoolingConfig) beanFactory.getBean("businessObject");
System.out.println("Max pool size is " + conf.getMaxSize());
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
val conf = beanFactory.getBean("businessObject") as PoolingConfig
println("Max pool size is " + conf.maxSize)
----
======
NOTE: Pooling stateless service objects is not usually necessary. We do not believe it should
be the default choice, as most stateless objects are naturally thread safe, and instance
pooling is problematic if resources are cached.
Simpler pooling is available by using auto-proxying. You can set the `TargetSource` implementations
used by any auto-proxy creator.
[[aop-ts-prototype]]
== Prototype Target Sources
Setting up a "`prototype`" target source is similar to setting up a pooling `TargetSource`. In this
case, a new instance of the target is created on every method invocation. Although
the cost of creating a new object is not high in a modern JVM, the cost of wiring up the
new object (satisfying its IoC dependencies) may be more expensive. Thus, you should not
use this approach without very good reason.
To do this, you could modify the `poolTargetSource` definition shown earlier as follows
(we also changed the name, for clarity):
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean id="prototypeTargetSource" class="org.springframework.aop.target.PrototypeTargetSource">
<property name="targetBeanName" ref="businessObjectTarget"/>
</bean>
----
The only property is the name of the target bean. Inheritance is used in the
`TargetSource` implementations to ensure consistent naming. As with the pooling target
source, the target bean must be a prototype bean definition.
[[aop-ts-threadlocal]]
== `ThreadLocal` Target Sources
`ThreadLocal` target sources are useful if you need an object to be created for each
incoming request (per thread that is). The concept of a `ThreadLocal` provides a JDK-wide
facility to transparently store a resource alongside a thread. Setting up a
`ThreadLocalTargetSource` is pretty much the same as was explained for the other types
of target source, as the following example shows:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean id="threadlocalTargetSource" class="org.springframework.aop.target.ThreadLocalTargetSource">
<property name="targetBeanName" value="businessObjectTarget"/>
</bean>
----
NOTE: `ThreadLocal` instances come with serious issues (potentially resulting in memory leaks) when
incorrectly using them in multi-threaded and multi-classloader environments. You
should always consider wrapping a `ThreadLocal` in some other class and never directly use
the `ThreadLocal` itself (except in the wrapper class). Also, you should
always remember to correctly set and unset (where the latter simply involves a call to
`ThreadLocal.set(null)`) the resource local to the thread. Unsetting should be done in
any case, since not unsetting it might result in problematic behavior. Spring's
`ThreadLocal` support does this for you and should always be considered in favor of using
`ThreadLocal` instances without other proper handling code.
@@ -1,38 +0,0 @@
[[aop]]
= Aspect Oriented Programming with Spring
Aspect-oriented Programming (AOP) complements Object-oriented Programming (OOP) by
providing another way of thinking about program structure. The key unit of modularity
in OOP is the class, whereas in AOP the unit of modularity is the aspect. Aspects
enable the modularization of concerns (such as transaction management) that cut across
multiple types and objects. (Such concerns are often termed "crosscutting" concerns
in AOP literature.)
One of the key components of Spring is the AOP framework. While the Spring IoC
container does not depend on AOP (meaning you do not need to use AOP if you don't want
to), AOP complements Spring IoC to provide a very capable middleware solution.
.Spring AOP with AspectJ pointcuts
****
Spring provides simple and powerful ways of writing custom aspects by using either a
xref:core/aop/schema.adoc[schema-based approach] or the xref:core/aop/ataspectj.adoc[@AspectJ annotation style].
Both of these styles offer fully typed advice and use of the AspectJ pointcut language
while still using Spring AOP for weaving.
This chapter discusses the schema- and @AspectJ-based AOP support.
The lower-level AOP support is discussed in xref:core/aop-api.adoc[the following chapter].
****
AOP is used in the Spring Framework to:
* Provide declarative enterprise services. The most important such service is
xref:data-access/transaction/declarative.adoc[declarative transaction management].
* Let users implement custom aspects, complementing their use of OOP with AOP.
NOTE: If you are interested only in generic declarative services or other pre-packaged
declarative middleware services such as pooling, you do not need to work directly with
Spring AOP, and can skip most of this chapter.
@@ -1,59 +0,0 @@
[[aop-aspectj-programmatic]]
= Programmatic Creation of @AspectJ Proxies
In addition to declaring aspects in your configuration by using either `<aop:config>`
or `<aop:aspectj-autoproxy>`, it is also possible to programmatically create proxies
that advise target objects. For the full details of Spring's AOP API, see the
xref:core/aop-api.adoc[next chapter]. Here, we want to focus on the ability to automatically
create proxies by using @AspectJ aspects.
You can use the `org.springframework.aop.aspectj.annotation.AspectJProxyFactory` class
to create a proxy for a target object that is advised by one or more @AspectJ aspects.
The basic usage for this class is very simple, as the following example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
// create a factory that can generate a proxy for the given target object
AspectJProxyFactory factory = new AspectJProxyFactory(targetObject);
// add an aspect, the class must be an @AspectJ aspect
// you can call this as many times as you need with different aspects
factory.addAspect(SecurityManager.class);
// you can also add existing aspect instances, the type of the object supplied
// must be an @AspectJ aspect
factory.addAspect(usageTracker);
// now get the proxy object...
MyInterfaceType proxy = factory.getProxy();
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
// create a factory that can generate a proxy for the given target object
val factory = AspectJProxyFactory(targetObject)
// add an aspect, the class must be an @AspectJ aspect
// you can call this as many times as you need with different aspects
factory.addAspect(SecurityManager::class.java)
// you can also add existing aspect instances, the type of the object supplied
// must be an @AspectJ aspect
factory.addAspect(usageTracker)
// now get the proxy object...
val proxy = factory.getProxy<Any>()
----
======
See the {spring-framework-api}/aop/aspectj/annotation/AspectJProxyFactory.html[javadoc] for more information.
@@ -1,16 +0,0 @@
[[aop-ataspectj]]
= @AspectJ support
:page-section-summary-toc: 1
@AspectJ refers to a style of declaring aspects as regular Java classes annotated with
annotations. The @AspectJ style was introduced by the
{aspectj-site}[AspectJ project] as part of the AspectJ 5 release. Spring
interprets the same annotations as AspectJ 5, using a library supplied by AspectJ
for pointcut parsing and matching. The AOP runtime is still pure Spring AOP, though, and
there is no dependency on the AspectJ compiler or weaver.
NOTE: Using the AspectJ compiler and weaver enables use of the full AspectJ language and
is discussed in xref:core/aop/using-aspectj.adoc[Using AspectJ with Spring Applications].
@@ -1,941 +0,0 @@
[[aop-advice]]
= Declaring Advice
Advice is associated with a pointcut expression and runs before, after, or around method
executions matched by the pointcut. The pointcut expression may be either an _inline
pointcut_ or a reference to a xref:core/aop/ataspectj/pointcuts.adoc#aop-common-pointcuts[_named pointcut_].
[[aop-advice-before]]
== Before Advice
You can declare before advice in an aspect by using the `@Before` annotation.
The following example uses an inline pointcut expression.
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
@Aspect
public class BeforeExample {
@Before("execution(* com.xyz.dao.*.*(..))")
public void doAccessCheck() {
// ...
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
import org.aspectj.lang.annotation.Aspect
import org.aspectj.lang.annotation.Before
@Aspect
class BeforeExample {
@Before("execution(* com.xyz.dao.*.*(..))")
fun doAccessCheck() {
// ...
}
}
----
======
If we use a xref:core/aop/ataspectj/pointcuts.adoc#aop-common-pointcuts[named pointcut], we can rewrite the preceding example
as follows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
@Aspect
public class BeforeExample {
@Before("com.xyz.CommonPointcuts.dataAccessOperation()")
public void doAccessCheck() {
// ...
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
import org.aspectj.lang.annotation.Aspect
import org.aspectj.lang.annotation.Before
@Aspect
class BeforeExample {
@Before("com.xyz.CommonPointcuts.dataAccessOperation()")
fun doAccessCheck() {
// ...
}
}
----
======
[[aop-advice-after-returning]]
== After Returning Advice
After returning advice runs when a matched method execution returns normally.
You can declare it by using the `@AfterReturning` annotation.
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.AfterReturning;
@Aspect
public class AfterReturningExample {
@AfterReturning("execution(* com.xyz.dao.*.*(..))")
public void doAccessCheck() {
// ...
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
import org.aspectj.lang.annotation.Aspect
import org.aspectj.lang.annotation.AfterReturning
@Aspect
class AfterReturningExample {
@AfterReturning("execution(* com.xyz.dao.*.*(..))")
fun doAccessCheck() {
// ...
}
}
----
======
NOTE: You can have multiple advice declarations (and other members as well),
all inside the same aspect. We show only a single advice declaration in these
examples to focus the effect of each one.
Sometimes, you need access in the advice body to the actual value that was returned.
You can use the form of `@AfterReturning` that binds the return value to get that
access, as the following example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.AfterReturning;
@Aspect
public class AfterReturningExample {
@AfterReturning(
pointcut="execution(* com.xyz.dao.*.*(..))",
returning="retVal")
public void doAccessCheck(Object retVal) {
// ...
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
import org.aspectj.lang.annotation.Aspect
import org.aspectj.lang.annotation.AfterReturning
@Aspect
class AfterReturningExample {
@AfterReturning(
pointcut = "execution(* com.xyz.dao.*.*(..))",
returning = "retVal")
fun doAccessCheck(retVal: Any?) {
// ...
}
}
----
======
The name used in the `returning` attribute must correspond to the name of a parameter
in the advice method. When a method execution returns, the return value is passed to
the advice method as the corresponding argument value. A `returning` clause also
restricts matching to only those method executions that return a value of the
specified type (in this case, `Object`, which matches any return value).
Please note that it is not possible to return a totally different reference when
using after returning advice.
[[aop-advice-after-throwing]]
== After Throwing Advice
After throwing advice runs when a matched method execution exits by throwing an
exception. You can declare it by using the `@AfterThrowing` annotation, as the
following example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.AfterThrowing;
@Aspect
public class AfterThrowingExample {
@AfterThrowing("execution(* com.xyz.dao.*.*(..))")
public void doRecoveryActions() {
// ...
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
import org.aspectj.lang.annotation.Aspect
import org.aspectj.lang.annotation.AfterThrowing
@Aspect
class AfterThrowingExample {
@AfterThrowing("execution(* com.xyz.dao.*.*(..))")
fun doRecoveryActions() {
// ...
}
}
----
======
Often, you want the advice to run only when exceptions of a given type are thrown,
and you also often need access to the thrown exception in the advice body. You can
use the `throwing` attribute to both restrict matching (if desired -- use `Throwable`
as the exception type otherwise) and bind the thrown exception to an advice parameter.
The following example shows how to do so:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.AfterThrowing;
@Aspect
public class AfterThrowingExample {
@AfterThrowing(
pointcut="execution(* com.xyz.dao.*.*(..))",
throwing="ex")
public void doRecoveryActions(DataAccessException ex) {
// ...
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
import org.aspectj.lang.annotation.Aspect
import org.aspectj.lang.annotation.AfterThrowing
@Aspect
class AfterThrowingExample {
@AfterThrowing(
pointcut = "execution(* com.xyz.dao.*.*(..))",
throwing = "ex")
fun doRecoveryActions(ex: DataAccessException) {
// ...
}
}
----
======
The name used in the `throwing` attribute must correspond to the name of a parameter in
the advice method. When a method execution exits by throwing an exception, the exception
is passed to the advice method as the corresponding argument value. A `throwing` clause
also restricts matching to only those method executions that throw an exception of the
specified type (`DataAccessException`, in this case).
[NOTE]
====
Note that `@AfterThrowing` does not indicate a general exception handling callback.
Specifically, an `@AfterThrowing` advice method is only supposed to receive exceptions
from the join point (user-declared target method) itself but not from an accompanying
`@After`/`@AfterReturning` method.
====
[[aop-advice-after-finally]]
== After (Finally) Advice
After (finally) advice runs when a matched method execution exits. It is declared by
using the `@After` annotation. After advice must be prepared to handle both normal and
exception return conditions. It is typically used for releasing resources and similar
purposes. The following example shows how to use after finally advice:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.After;
@Aspect
public class AfterFinallyExample {
@After("execution(* com.xyz.dao.*.*(..))")
public void doReleaseLock() {
// ...
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
import org.aspectj.lang.annotation.Aspect
import org.aspectj.lang.annotation.After
@Aspect
class AfterFinallyExample {
@After("execution(* com.xyz.dao.*.*(..))")
fun doReleaseLock() {
// ...
}
}
----
======
[NOTE]
====
Note that `@After` advice in AspectJ is defined as "after finally advice", analogous
to a finally block in a try-catch statement. It will be invoked for any outcome,
normal return or exception thrown from the join point (user-declared target method),
in contrast to `@AfterReturning` which only applies to successful normal returns.
====
[[aop-ataspectj-around-advice]]
== Around Advice
The last kind of advice is _around_ advice. Around advice runs "around" a matched
method's execution. It has the opportunity to do work both before and after the method
runs and to determine when, how, and even if the method actually gets to run at all.
Around advice is often used if you need to share state before and after a method
execution in a thread-safe manner for example, starting and stopping a timer.
[TIP]
====
Always use the least powerful form of advice that meets your requirements.
For example, do not use _around_ advice if _before_ advice is sufficient for your needs.
====
Around advice is declared by annotating a method with the `@Around` annotation. The
method should declare `Object` as its return type, and the first parameter of the method
must be of type `ProceedingJoinPoint`. Within the body of the advice method, you must
invoke `proceed()` on the `ProceedingJoinPoint` in order for the underlying method to
run. Invoking `proceed()` without arguments will result in the caller's original
arguments being supplied to the underlying method when it is invoked. For advanced use
cases, there is an overloaded variant of the `proceed()` method which accepts an array of
arguments (`Object[]`). The values in the array will be used as the arguments to the
underlying method when it is invoked.
[NOTE]
====
The behavior of `proceed` when called with an `Object[]` is a little different than the
behavior of `proceed` for around advice compiled by the AspectJ compiler. For around
advice written using the traditional AspectJ language, the number of arguments passed to
`proceed` must match the number of arguments passed to the around advice (not the number
of arguments taken by the underlying join point), and the value passed to proceed in a
given argument position supplants the original value at the join point for the entity the
value was bound to (do not worry if this does not make sense right now).
The approach taken by Spring is simpler and a better match to its proxy-based,
execution-only semantics. You only need to be aware of this difference if you compile
`@AspectJ` aspects written for Spring and use `proceed` with arguments with the AspectJ
compiler and weaver. There is a way to write such aspects that is 100% compatible across
both Spring AOP and AspectJ, and this is discussed in the
xref:core/aop/ataspectj/advice.adoc#aop-ataspectj-advice-proceeding-with-the-call[following section on advice parameters].
====
The value returned by the around advice is the return value seen by the caller of the
method. For example, a simple caching aspect could return a value from a cache if it has
one or invoke `proceed()` (and return that value) if it does not. Note that `proceed`
may be invoked once, many times, or not at all within the body of the around advice. All
of these are legal.
WARNING: If you declare the return type of your around advice method as `void`, `null`
will always be returned to the caller, effectively ignoring the result of any invocation
of `proceed()`. It is therefore recommended that an around advice method declare a return
type of `Object`. The advice method should typically return the value returned from an
invocation of `proceed()`, even if the underlying method has a `void` return type.
However, the advice may optionally return a cached value, a wrapped value, or some other
value depending on the use case.
The following example shows how to use around advice:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.ProceedingJoinPoint;
@Aspect
public class AroundExample {
@Around("execution(* com.xyz..service.*.*(..))")
public Object doBasicProfiling(ProceedingJoinPoint pjp) throws Throwable {
// start stopwatch
Object retVal = pjp.proceed();
// stop stopwatch
return retVal;
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
import org.aspectj.lang.annotation.Aspect
import org.aspectj.lang.annotation.Around
import org.aspectj.lang.ProceedingJoinPoint
@Aspect
class AroundExample {
@Around("execution(* com.xyz..service.*.*(..))")
fun doBasicProfiling(pjp: ProceedingJoinPoint): Any? {
// start stopwatch
val retVal = pjp.proceed()
// stop stopwatch
return retVal
}
}
----
======
[[aop-ataspectj-advice-params]]
== Advice Parameters
Spring offers fully typed advice, meaning that you declare the parameters you need in the
advice signature (as we saw earlier for the returning and throwing examples) rather than
work with `Object[]` arrays all the time. We see how to make argument and other contextual
values available to the advice body later in this section. First, we take a look at how to
write generic advice that can find out about the method the advice is currently advising.
[[aop-ataspectj-advice-params-the-joinpoint]]
=== Access to the Current `JoinPoint`
Any advice method may declare, as its first parameter, a parameter of type
`org.aspectj.lang.JoinPoint`. Note that around advice is required to declare a first
parameter of type `ProceedingJoinPoint`, which is a subclass of `JoinPoint`.
The `JoinPoint` interface provides a number of useful methods:
* `getArgs()`: Returns the method arguments.
* `getThis()`: Returns the proxy object.
* `getTarget()`: Returns the target object.
* `getSignature()`: Returns a description of the method that is being advised.
* `toString()`: Prints a useful description of the method being advised.
See the {aspectj-api}/org/aspectj/lang/JoinPoint.html[javadoc] for more detail.
[[aop-ataspectj-advice-params-passing]]
=== Passing Parameters to Advice
We have already seen how to bind the returned value or exception value (using after
returning and after throwing advice). To make argument values available to the advice
body, you can use the binding form of `args`. If you use a parameter name in place of a
type name in an `args` expression, the value of the corresponding argument is passed as
the parameter value when the advice is invoked. An example should make this clearer.
Suppose you want to advise the execution of DAO operations that take an `Account`
object as the first parameter, and you need access to the account in the advice body.
You could write the following:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
@Before("execution(* com.xyz.dao.*.*(..)) && args(account,..)")
public void validateAccount(Account account) {
// ...
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
@Before("execution(* com.xyz.dao.*.*(..)) && args(account,..)")
fun validateAccount(account: Account) {
// ...
}
----
======
The `args(account,..)` part of the pointcut expression serves two purposes. First, it
restricts matching to only those method executions where the method takes at least one
parameter, and the argument passed to that parameter is an instance of `Account`.
Second, it makes the actual `Account` object available to the advice through the `account`
parameter.
Another way of writing this is to declare a pointcut that "provides" the `Account`
object value when it matches a join point, and then refer to the named pointcut
from the advice. This would look as follows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
@Pointcut("execution(* com.xyz.dao.*.*(..)) && args(account,..)")
private void accountDataAccessOperation(Account account) {}
@Before("accountDataAccessOperation(account)")
public void validateAccount(Account account) {
// ...
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
@Pointcut("execution(* com.xyz.dao.*.*(..)) && args(account,..)")
private fun accountDataAccessOperation(account: Account) {
}
@Before("accountDataAccessOperation(account)")
fun validateAccount(account: Account) {
// ...
}
----
======
See the AspectJ programming guide for more details.
The proxy object (`this`), target object (`target`), and annotations (`@within`,
`@target`, `@annotation`, and `@args`) can all be bound in a similar fashion. The next
set of examples shows how to match the execution of methods annotated with an
`@Auditable` annotation and extract the audit code:
The following shows the definition of the `@Auditable` annotation:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface Auditable {
AuditCode value();
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
@Retention(AnnotationRetention.RUNTIME)
@Target(AnnotationTarget.FUNCTION)
annotation class Auditable(val value: AuditCode)
----
======
The following shows the advice that matches the execution of `@Auditable` methods:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
@Before("com.xyz.Pointcuts.publicMethod() && @annotation(auditable)") // <1>
public void audit(Auditable auditable) {
AuditCode code = auditable.value();
// ...
}
----
<1> References the `publicMethod` named pointcut defined in xref:core/aop/ataspectj/pointcuts.adoc#aop-pointcuts-combining[Combining Pointcut Expressions].
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
@Before("com.xyz.Pointcuts.publicMethod() && @annotation(auditable)") // <1>
fun audit(auditable: Auditable) {
val code = auditable.value()
// ...
}
----
<1> References the `publicMethod` named pointcut defined in xref:core/aop/ataspectj/pointcuts.adoc#aop-pointcuts-combining[Combining Pointcut Expressions].
======
[[aop-ataspectj-advice-params-generics]]
=== Advice Parameters and Generics
Spring AOP can handle generics used in class declarations and method parameters. Suppose
you have a generic type like the following:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
public interface Sample<T> {
void sampleGenericMethod(T param);
void sampleGenericCollectionMethod(Collection<T> param);
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
interface Sample<T> {
fun sampleGenericMethod(param: T)
fun sampleGenericCollectionMethod(param: Collection<T>)
}
----
======
You can restrict interception of method types to certain parameter types by
tying the advice parameter to the parameter type for which you want to intercept the method:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
@Before("execution(* ..Sample+.sampleGenericMethod(*)) && args(param)")
public void beforeSampleMethod(MyType param) {
// Advice implementation
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
@Before("execution(* ..Sample+.sampleGenericMethod(*)) && args(param)")
fun beforeSampleMethod(param: MyType) {
// Advice implementation
}
----
======
This approach does not work for generic collections. So you cannot define a
pointcut as follows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
@Before("execution(* ..Sample+.sampleGenericCollectionMethod(*)) && args(param)")
public void beforeSampleMethod(Collection<MyType> param) {
// Advice implementation
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
@Before("execution(* ..Sample+.sampleGenericCollectionMethod(*)) && args(param)")
fun beforeSampleMethod(param: Collection<MyType>) {
// Advice implementation
}
----
======
To make this work, we would have to inspect every element of the collection, which is not
reasonable, as we also cannot decide how to treat `null` values in general. To achieve
something similar to this, you have to type the parameter to `Collection<?>` and manually
check the type of the elements.
[[aop-ataspectj-advice-params-names]]
=== Determining Argument Names
Parameter binding in advice invocations relies on matching the names used in pointcut
expressions to the parameter names declared in advice and pointcut method signatures.
NOTE: This section uses the terms _argument_ and _parameter_ interchangeably, since
AspectJ APIs refer to parameter names as argument names.
Spring AOP uses the following `ParameterNameDiscoverer` implementations to determine
parameter names. Each discoverer will be given a chance to discover parameter names, and
the first successful discoverer wins. If none of the registered discoverers is capable
of determining parameter names, an exception will be thrown.
`AspectJAnnotationParameterNameDiscoverer` :: Uses parameter names that have been explicitly
specified by the user via the `argNames` attribute in the corresponding advice or
pointcut annotation. See xref:core/aop/ataspectj/advice.adoc#aop-ataspectj-advice-params-names-explicit[Explicit Argument Names] for details.
`KotlinReflectionParameterNameDiscoverer` :: Uses Kotlin reflection APIs to determine
parameter names. This discoverer is only used if such APIs are present on the classpath.
`StandardReflectionParameterNameDiscoverer` :: Uses the standard `java.lang.reflect.Parameter`
API to determine parameter names. Requires that code be compiled with the `-parameters`
flag for `javac`. Recommended approach on Java 8+.
`AspectJAdviceParameterNameDiscoverer` :: Deduces parameter names from the pointcut
expression, `returning`, and `throwing` clauses. See the
{spring-framework-api}/aop/aspectj/AspectJAdviceParameterNameDiscoverer.html[javadoc]
for details on the algorithm used.
[[aop-ataspectj-advice-params-names-explicit]]
=== Explicit Argument Names
@AspectJ advice and pointcut annotations have an optional `argNames` attribute that you
can use to specify the argument names of the annotated method.
[TIP]
====
If an @AspectJ aspect has been compiled by the AspectJ compiler (`ajc`) even without
debug information, you do not need to add the `argNames` attribute, since the compiler
retains the needed information.
Similarly, if an @AspectJ aspect has been compiled with `javac` using the `-parameters`
flag, you do not need to add the `argNames` attribute, since the compiler retains the
needed information.
====
The following example shows how to use the `argNames` attribute:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
@Before(
value = "com.xyz.Pointcuts.publicMethod() && target(bean) && @annotation(auditable)", // <1>
argNames = "bean,auditable") // <2>
public void audit(Object bean, Auditable auditable) {
AuditCode code = auditable.value();
// ... use code and bean
}
----
<1> References the `publicMethod` named pointcut defined in xref:core/aop/ataspectj/pointcuts.adoc#aop-pointcuts-combining[Combining Pointcut Expressions].
<2> Declares `bean` and `auditable` as the argument names.
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
@Before(
value = "com.xyz.Pointcuts.publicMethod() && target(bean) && @annotation(auditable)", // <1>
argNames = "bean,auditable") // <2>
fun audit(bean: Any, auditable: Auditable) {
val code = auditable.value()
// ... use code and bean
}
----
<1> References the `publicMethod` named pointcut defined in xref:core/aop/ataspectj/pointcuts.adoc#aop-pointcuts-combining[Combining Pointcut Expressions].
<2> Declares `bean` and `auditable` as the argument names.
======
If the first parameter is of type `JoinPoint`, `ProceedingJoinPoint`, or
`JoinPoint.StaticPart`, you can omit the name of the parameter from the value of the
`argNames` attribute. For example, if you modify the preceding advice to receive the join
point object, the `argNames` attribute does not need to include it:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
@Before(
value = "com.xyz.Pointcuts.publicMethod() && target(bean) && @annotation(auditable)", // <1>
argNames = "bean,auditable") // <2>
public void audit(JoinPoint jp, Object bean, Auditable auditable) {
AuditCode code = auditable.value();
// ... use code, bean, and jp
}
----
<1> References the `publicMethod` named pointcut defined in xref:core/aop/ataspectj/pointcuts.adoc#aop-pointcuts-combining[Combining Pointcut Expressions].
<2> Declares `bean` and `auditable` as the argument names.
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
@Before(
value = "com.xyz.Pointcuts.publicMethod() && target(bean) && @annotation(auditable)", // <1>
argNames = "bean,auditable") // <2>
fun audit(jp: JoinPoint, bean: Any, auditable: Auditable) {
val code = auditable.value()
// ... use code, bean, and jp
}
----
<1> References the `publicMethod` named pointcut defined in xref:core/aop/ataspectj/pointcuts.adoc#aop-pointcuts-combining[Combining Pointcut Expressions].
<2> Declares `bean` and `auditable` as the argument names.
======
The special treatment given to the first parameter of type `JoinPoint`,
`ProceedingJoinPoint`, or `JoinPoint.StaticPart` is particularly convenient for advice
methods that do not collect any other join point context. In such situations, you may
omit the `argNames` attribute. For example, the following advice does not need to declare
the `argNames` attribute:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
@Before("com.xyz.Pointcuts.publicMethod()") // <1>
public void audit(JoinPoint jp) {
// ... use jp
}
----
<1> References the `publicMethod` named pointcut defined in xref:core/aop/ataspectj/pointcuts.adoc#aop-pointcuts-combining[Combining Pointcut Expressions].
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
@Before("com.xyz.Pointcuts.publicMethod()") // <1>
fun audit(jp: JoinPoint) {
// ... use jp
}
----
<1> References the `publicMethod` named pointcut defined in xref:core/aop/ataspectj/pointcuts.adoc#aop-pointcuts-combining[Combining Pointcut Expressions].
======
[[aop-ataspectj-advice-proceeding-with-the-call]]
=== Proceeding with Arguments
We remarked earlier that we would describe how to write a `proceed` call with
arguments that works consistently across Spring AOP and AspectJ. The solution is
to ensure that the advice signature binds each of the method parameters in order.
The following example shows how to do so:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
@Around("execution(List<Account> find*(..)) && " +
"com.xyz.CommonPointcuts.inDataAccessLayer() && " +
"args(accountHolderNamePattern)") // <1>
public Object preProcessQueryPattern(ProceedingJoinPoint pjp,
String accountHolderNamePattern) throws Throwable {
String newPattern = preProcess(accountHolderNamePattern);
return pjp.proceed(new Object[] {newPattern});
}
----
<1> References the `inDataAccessLayer` named pointcut defined in xref:core/aop/ataspectj/pointcuts.adoc#aop-common-pointcuts[Sharing Named Pointcut Definitions].
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
@Around("execution(List<Account> find*(..)) && " +
"com.xyz.CommonPointcuts.inDataAccessLayer() && " +
"args(accountHolderNamePattern)") // <1>
fun preProcessQueryPattern(pjp: ProceedingJoinPoint,
accountHolderNamePattern: String): Any? {
val newPattern = preProcess(accountHolderNamePattern)
return pjp.proceed(arrayOf<Any>(newPattern))
}
----
<1> References the `inDataAccessLayer` named pointcut defined in xref:core/aop/ataspectj/pointcuts.adoc#aop-common-pointcuts[Sharing Named Pointcut Definitions].
======
In many cases, you do this binding anyway (as in the preceding example).
[[aop-ataspectj-advice-ordering]]
== Advice Ordering
What happens when multiple pieces of advice all want to run at the same join point?
Spring AOP follows the same precedence rules as AspectJ to determine the order of advice
execution. The highest precedence advice runs first "on the way in" (so, given two pieces
of before advice, the one with highest precedence runs first). "On the way out" from a
join point, the highest precedence advice runs last (so, given two pieces of after
advice, the one with the highest precedence will run second).
When two pieces of advice defined in different aspects both need to run at the same
join point, unless you specify otherwise, the order of execution is undefined. You can
control the order of execution by specifying precedence. This is done in the normal
Spring way by either implementing the `org.springframework.core.Ordered` interface in
the aspect class or annotating it with the `@Order` annotation. Given two aspects, the
aspect returning the lower value from `Ordered.getOrder()` (or the annotation value) has
the higher precedence.
[NOTE]
====
Each of the distinct advice types of a particular aspect is conceptually meant to apply
to the join point directly. As a consequence, an `@AfterThrowing` advice method is not
supposed to receive an exception from an accompanying `@After`/`@AfterReturning` method.
As of Spring Framework 5.2.7, advice methods defined in the same `@Aspect` class that
need to run at the same join point are assigned precedence based on their advice type in
the following order, from highest to lowest precedence: `@Around`, `@Before`, `@After`,
`@AfterReturning`, `@AfterThrowing`. Note, however, that an `@After` advice method will
effectively be invoked after any `@AfterReturning` or `@AfterThrowing` advice methods
in the same aspect, following AspectJ's "after finally advice" semantics for `@After`.
When two pieces of the same type of advice (for example, two `@After` advice methods)
defined in the same `@Aspect` class both need to run at the same join point, the ordering
is undefined (since there is no way to retrieve the source code declaration order through
reflection for javac-compiled classes). Consider collapsing such advice methods into one
advice method per join point in each `@Aspect` class or refactor the pieces of advice into
separate `@Aspect` classes that you can order at the aspect level via `Ordered` or `@Order`.
====
@@ -1,61 +0,0 @@
[[aop-aspectj-support]]
= Enabling @AspectJ Support
To use @AspectJ aspects in a Spring configuration, you need to enable Spring support for
configuring Spring AOP based on @AspectJ aspects and auto-proxying beans based on
whether or not they are advised by those aspects. By auto-proxying, we mean that, if Spring
determines that a bean is advised by one or more aspects, it automatically generates
a proxy for that bean to intercept method invocations and ensures that advice is run
as needed.
The @AspectJ support can be enabled with XML- or Java-style configuration. In either
case, you also need to ensure that AspectJ's `aspectjweaver.jar` library is on the
classpath of your application (version 1.9 or later). This library is available in the
`lib` directory of an AspectJ distribution or from the Maven Central repository.
[[aop-enable-aspectj-java]]
== Enabling @AspectJ Support with Java Configuration
To enable @AspectJ support with Java `@Configuration`, add the `@EnableAspectJAutoProxy`
annotation, as the following example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
@Configuration
@EnableAspectJAutoProxy
public class AppConfig {
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
@Configuration
@EnableAspectJAutoProxy
class AppConfig
----
======
[[aop-enable-aspectj-xml]]
== Enabling @AspectJ Support with XML Configuration
To enable @AspectJ support with XML-based configuration, use the `aop:aspectj-autoproxy`
element, as the following example shows:
[source,xml,indent=0,subs="verbatim"]
----
<aop:aspectj-autoproxy/>
----
This assumes that you use schema support as described in
xref:core/appendix/xsd-schemas.adoc[XML Schema-based configuration].
See xref:core/appendix/xsd-schemas.adoc#aop[the AOP schema] for how to
import the tags in the `aop` namespace.
@@ -1,68 +0,0 @@
[[aop-at-aspectj]]
= Declaring an Aspect
With @AspectJ support enabled, any bean defined in your application context with a
class that is an @AspectJ aspect (has the `@Aspect` annotation) is automatically
detected by Spring and used to configure Spring AOP. The next two examples show the
minimal steps required for a not-very-useful aspect.
The first of the two examples shows a regular bean definition in the application context
that points to a bean class that is annotated with `@Aspect`:
[source,xml,indent=0,subs="verbatim"]
----
<bean id="myAspect" class="com.xyz.NotVeryUsefulAspect">
<!-- configure properties of the aspect here -->
</bean>
----
The second of the two examples shows the `NotVeryUsefulAspect` class definition, which is
annotated with `@Aspect`:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary",chomp="-packages",fold="none"]
----
package com.xyz;
import org.aspectj.lang.annotation.Aspect;
@Aspect
public class NotVeryUsefulAspect {
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary",chomp="-packages",fold="none"]
----
package com.xyz
import org.aspectj.lang.annotation.Aspect
@Aspect
class NotVeryUsefulAspect
----
======
Aspects (classes annotated with `@Aspect`) can have methods and fields, the same as any
other class. They can also contain pointcut, advice, and introduction (inter-type)
declarations.
.Autodetecting aspects through component scanning
NOTE: You can register aspect classes as regular beans in your Spring XML configuration,
via `@Bean` methods in `@Configuration` classes, or have Spring autodetect them through
classpath scanning -- the same as any other Spring-managed bean. However, note that the
`@Aspect` annotation is not sufficient for autodetection in the classpath. For that
purpose, you need to add a separate `@Component` annotation (or, alternatively, a custom
stereotype annotation that qualifies, as per the rules of Spring's component scanner).
.Advising aspects with other aspects?
NOTE: In Spring AOP, aspects themselves cannot be the targets of advice from other
aspects. The `@Aspect` annotation on a class marks it as an aspect and, hence, excludes
it from auto-proxying.
@@ -1,183 +0,0 @@
[[aop-ataspectj-example]]
= An AOP Example
Now that you have seen how all the constituent parts work, we can put them together to do
something useful.
The execution of business services can sometimes fail due to concurrency issues (for
example, a deadlock loser). If the operation is retried, it is likely to succeed
on the next try. For business services where it is appropriate to retry in such
conditions (idempotent operations that do not need to go back to the user for conflict
resolution), we want to transparently retry the operation to avoid the client seeing a
`PessimisticLockingFailureException`. This is a requirement that clearly cuts across
multiple services in the service layer and, hence, is ideal for implementing through an
aspect.
Because we want to retry the operation, we need to use around advice so that we can
call `proceed` multiple times. The following listing shows the basic aspect implementation:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
@Aspect
public class ConcurrentOperationExecutor implements Ordered {
private static final int DEFAULT_MAX_RETRIES = 2;
private int maxRetries = DEFAULT_MAX_RETRIES;
private int order = 1;
public void setMaxRetries(int maxRetries) {
this.maxRetries = maxRetries;
}
public int getOrder() {
return this.order;
}
public void setOrder(int order) {
this.order = order;
}
@Around("com.xyz.CommonPointcuts.businessService()") // <1>
public Object doConcurrentOperation(ProceedingJoinPoint pjp) throws Throwable {
int numAttempts = 0;
PessimisticLockingFailureException lockFailureException;
do {
numAttempts++;
try {
return pjp.proceed();
}
catch(PessimisticLockingFailureException ex) {
lockFailureException = ex;
}
} while(numAttempts <= this.maxRetries);
throw lockFailureException;
}
}
----
<1> References the `businessService` named pointcut defined in xref:core/aop/ataspectj/pointcuts.adoc#aop-common-pointcuts[Sharing Named Pointcut Definitions].
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
@Aspect
class ConcurrentOperationExecutor : Ordered {
private val DEFAULT_MAX_RETRIES = 2
private var maxRetries = DEFAULT_MAX_RETRIES
private var order = 1
fun setMaxRetries(maxRetries: Int) {
this.maxRetries = maxRetries
}
override fun getOrder(): Int {
return this.order
}
fun setOrder(order: Int) {
this.order = order
}
@Around("com.xyz.CommonPointcuts.businessService()") // <1>
fun doConcurrentOperation(pjp: ProceedingJoinPoint): Any? {
var numAttempts = 0
var lockFailureException: PessimisticLockingFailureException
do {
numAttempts++
try {
return pjp.proceed()
} catch (ex: PessimisticLockingFailureException) {
lockFailureException = ex
}
} while (numAttempts <= this.maxRetries)
throw lockFailureException
}
}
----
<1> References the `businessService` named pointcut defined in xref:core/aop/ataspectj/pointcuts.adoc#aop-common-pointcuts[Sharing Named Pointcut Definitions].
======
Note that the aspect implements the `Ordered` interface so that we can set the precedence of
the aspect higher than the transaction advice (we want a fresh transaction each time we
retry). The `maxRetries` and `order` properties are both configured by Spring. The
main action happens in the `doConcurrentOperation` around advice. Notice that, for the
moment, we apply the retry logic to each `businessService`. We try to proceed,
and if we fail with a `PessimisticLockingFailureException`, we try again, unless
we have exhausted all of our retry attempts.
The corresponding Spring configuration follows:
[source,xml,indent=0,subs="verbatim"]
----
<aop:aspectj-autoproxy/>
<bean id="concurrentOperationExecutor"
class="com.xyz.service.impl.ConcurrentOperationExecutor">
<property name="maxRetries" value="3"/>
<property name="order" value="100"/>
</bean>
----
To refine the aspect so that it retries only idempotent operations, we might define the following
`Idempotent` annotation:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
@Retention(RetentionPolicy.RUNTIME)
// marker annotation
public @interface Idempotent {
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
@Retention(AnnotationRetention.RUNTIME)
// marker annotation
annotation class Idempotent
----
======
We can then use the annotation to annotate the implementation of service operations. The change
to the aspect to retry only idempotent operations involves refining the pointcut
expression so that only `@Idempotent` operations match, as follows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
@Around("execution(* com.xyz..service.*.*(..)) && " +
"@annotation(com.xyz.service.Idempotent)")
public Object doConcurrentOperation(ProceedingJoinPoint pjp) throws Throwable {
// ...
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
@Around("execution(* com.xyz..service.*.*(..)) && " +
"@annotation(com.xyz.service.Idempotent)")
fun doConcurrentOperation(pjp: ProceedingJoinPoint): Any? {
// ...
}
----
======
@@ -1,65 +0,0 @@
[[aop-instantiation-models]]
= Aspect Instantiation Models
NOTE: This is an advanced topic. If you are just starting out with AOP, you can safely skip
it until later.
By default, there is a single instance of each aspect within the application
context. AspectJ calls this the singleton instantiation model. It is possible to define
aspects with alternate lifecycles. Spring supports AspectJ's `perthis`, `pertarget`, and
`pertypewithin` instantiation models; `percflow` and `percflowbelow` are not currently
supported.
You can declare a `perthis` aspect by specifying a `perthis` clause in the `@Aspect`
annotation. Consider the following example:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
@Aspect("perthis(execution(* com.xyz..service.*.*(..)))")
public class MyAspect {
private int someState;
@Before("execution(* com.xyz..service.*.*(..))")
public void recordServiceUsage() {
// ...
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
@Aspect("perthis(execution(* com.xyz..service.*.*(..)))")
class MyAspect {
private val someState: Int = 0
@Before("execution(* com.xyz..service.*.*(..))")
fun recordServiceUsage() {
// ...
}
}
----
======
In the preceding example, the effect of the `perthis` clause is that one aspect instance
is created for each unique service object that performs a business service (each unique
object bound to `this` at join points matched by the pointcut expression). The aspect
instance is created the first time that a method is invoked on the service object. The
aspect goes out of scope when the service object goes out of scope. Before the aspect
instance is created, none of the advice within it runs. As soon as the aspect instance
has been created, the advice declared within it runs at matched join points, but only
when the service object is the one with which this aspect is associated. See the AspectJ
Programming Guide for more information on `per` clauses.
The `pertarget` instantiation model works in exactly the same way as `perthis`, but it
creates one aspect instance for each unique target object at matched join points.
@@ -1,79 +0,0 @@
[[aop-introductions]]
= Introductions
Introductions (known as inter-type declarations in AspectJ) enable an aspect to declare
that advised objects implement a given interface, and to provide an implementation of
that interface on behalf of those objects.
You can make an introduction by using the `@DeclareParents` annotation. This annotation
is used to declare that matching types have a new parent (hence the name). For example,
given an interface named `UsageTracked` and an implementation of that interface named
`DefaultUsageTracked`, the following aspect declares that all implementors of service
interfaces also implement the `UsageTracked` interface (e.g. for statistics via JMX):
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
@Aspect
public class UsageTracking {
@DeclareParents(value="com.xyz.service.*+", defaultImpl=DefaultUsageTracked.class)
public static UsageTracked mixin;
@Before("execution(* com.xyz..service.*.*(..)) && this(usageTracked)")
public void recordUsage(UsageTracked usageTracked) {
usageTracked.incrementUseCount();
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
@Aspect
class UsageTracking {
companion object {
@DeclareParents(value = "com.xyz.service.*+",
defaultImpl = DefaultUsageTracked::class)
lateinit var mixin: UsageTracked
}
@Before("execution(* com.xyz..service.*.*(..)) && this(usageTracked)")
fun recordUsage(usageTracked: UsageTracked) {
usageTracked.incrementUseCount()
}
}
----
======
The interface to be implemented is determined by the type of the annotated field. The
`value` attribute of the `@DeclareParents` annotation is an AspectJ type pattern. Any
bean of a matching type implements the `UsageTracked` interface. Note that, in the
before advice of the preceding example, service beans can be directly used as
implementations of the `UsageTracked` interface. If accessing a bean programmatically,
you would write the following:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
UsageTracked usageTracked = context.getBean("myService", UsageTracked.class);
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
val usageTracked = context.getBean("myService", UsageTracked.class)
----
======
@@ -1,586 +0,0 @@
[[aop-pointcuts]]
= Declaring a Pointcut
Pointcuts determine join points of interest and thus enable us to control
when advice runs. Spring AOP only supports method execution join points for Spring
beans, so you can think of a pointcut as matching the execution of methods on Spring
beans. A pointcut declaration has two parts: a signature comprising a name and any
parameters and a pointcut expression that determines exactly which method
executions we are interested in. In the @AspectJ annotation-style of AOP, a pointcut
signature is provided by a regular method definition, and the pointcut expression is
indicated by using the `@Pointcut` annotation (the method serving as the pointcut signature
must have a `void` return type).
An example may help make this distinction between a pointcut signature and a pointcut
expression clear. The following example defines a pointcut named `anyOldTransfer` that
matches the execution of any method named `transfer`:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
@Pointcut("execution(* transfer(..))") // the pointcut expression
private void anyOldTransfer() {} // the pointcut signature
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
@Pointcut("execution(* transfer(..))") // the pointcut expression
private fun anyOldTransfer() {} // the pointcut signature
----
======
The pointcut expression that forms the value of the `@Pointcut` annotation is a regular
AspectJ pointcut expression. For a full discussion of AspectJ's pointcut language, see
the {aspectj-docs-progguide}/index.html[AspectJ
Programming Guide] (and, for extensions, the
{aspectj-docs}/adk15notebook/index.html[AspectJ 5
Developer's Notebook]) or one of the books on AspectJ (such as _Eclipse AspectJ_, by Colyer
et al., or _AspectJ in Action_, by Ramnivas Laddad).
[[aop-pointcuts-designators]]
== Supported Pointcut Designators
Spring AOP supports the following AspectJ pointcut designators (PCD) for use in pointcut
expressions:
* `execution`: For matching method execution join points. This is the primary
pointcut designator to use when working with Spring AOP.
* `within`: Limits matching to join points within certain types (the execution
of a method declared within a matching type when using Spring AOP).
* `this`: Limits matching to join points (the execution of methods when using Spring
AOP) where the bean reference (Spring AOP proxy) is an instance of the given type.
* `target`: Limits matching to join points (the execution of methods when using
Spring AOP) where the target object (application object being proxied) is an instance
of the given type.
* `args`: Limits matching to join points (the execution of methods when using Spring
AOP) where the arguments are instances of the given types.
* `@target`: Limits matching to join points (the execution of methods when using
Spring AOP) where the class of the executing object has an annotation of the given type.
* `@args`: Limits matching to join points (the execution of methods when using Spring
AOP) where the runtime type of the actual arguments passed have annotations of the
given types.
* `@within`: Limits matching to join points within types that have the given
annotation (the execution of methods declared in types with the given annotation when
using Spring AOP).
* `@annotation`: Limits matching to join points where the subject of the join point
(the method being run in Spring AOP) has the given annotation.
.Other pointcut types
****
The full AspectJ pointcut language supports additional pointcut designators that are not
supported in Spring: `call`, `get`, `set`, `preinitialization`,
`staticinitialization`, `initialization`, `handler`, `adviceexecution`, `withincode`, `cflow`,
`cflowbelow`, `if`, `@this`, and `@withincode`. Use of these pointcut designators in pointcut
expressions interpreted by Spring AOP results in an `IllegalArgumentException` being
thrown.
The set of pointcut designators supported by Spring AOP may be extended in future
releases to support more of the AspectJ pointcut designators.
****
Because Spring AOP limits matching to only method execution join points, the preceding discussion
of the pointcut designators gives a narrower definition than you can find in the
AspectJ programming guide. In addition, AspectJ itself has type-based semantics and, at
an execution join point, both `this` and `target` refer to the same object: the
object executing the method. Spring AOP is a proxy-based system and differentiates
between the proxy object itself (which is bound to `this`) and the target object behind the
proxy (which is bound to `target`).
[NOTE]
====
Due to the proxy-based nature of Spring's AOP framework, calls within the target object
are, by definition, not intercepted. For JDK proxies, only public interface method
calls on the proxy can be intercepted. With CGLIB, public and protected method calls on
the proxy are intercepted (and even package-visible methods, if necessary). However,
common interactions through proxies should always be designed through public signatures.
Note that pointcut definitions are generally matched against any intercepted method.
If a pointcut is strictly meant to be public-only, even in a CGLIB proxy scenario with
potential non-public interactions through proxies, it needs to be defined accordingly.
If your interception needs include method calls or even constructors within the target
class, consider the use of Spring-driven xref:core/aop/using-aspectj.adoc#aop-aj-ltw[native AspectJ weaving] instead
of Spring's proxy-based AOP framework. This constitutes a different mode of AOP usage
with different characteristics, so be sure to make yourself familiar with weaving
before making a decision.
====
Spring AOP also supports an additional PCD named `bean`. This PCD lets you limit
the matching of join points to a particular named Spring bean or to a set of named
Spring beans (when using wildcards). The `bean` PCD has the following form:
[source,indent=0,subs="verbatim"]
----
bean(idOrNameOfBean)
----
The `idOrNameOfBean` token can be the name of any Spring bean. Limited wildcard
support that uses the `*` character is provided, so, if you establish some naming
conventions for your Spring beans, you can write a `bean` PCD expression
to select them. As is the case with other pointcut designators, the `bean` PCD can
be used with the `&&` (and), `||` (or), and `!` (negation) operators, too.
[NOTE]
====
The `bean` PCD is supported only in Spring AOP and not in
native AspectJ weaving. It is a Spring-specific extension to the standard PCDs that
AspectJ defines and is, therefore, not available for aspects declared in the `@Aspect` model.
The `bean` PCD operates at the instance level (building on the Spring bean name
concept) rather than at the type level only (to which weaving-based AOP is limited).
Instance-based pointcut designators are a special capability of Spring's
proxy-based AOP framework and its close integration with the Spring bean factory, where
it is natural and straightforward to identify specific beans by name.
====
[[aop-pointcuts-combining]]
== Combining Pointcut Expressions
You can combine pointcut expressions by using `&&,` `||` and `!`. You can also refer to
pointcut expressions by name. The following example shows three pointcut expressions:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary",chomp="-packages"]
----
package com.xyz;
public class Pointcuts {
@Pointcut("execution(public * *(..))")
public void publicMethod() {} // <1>
@Pointcut("within(com.xyz.trading..*)")
public void inTrading() {} // <2>
@Pointcut("publicMethod() && inTrading()")
public void tradingOperation() {} // <3>
}
----
<1> `publicMethod` matches if a method execution join point represents the execution
of any public method.
<2> `inTrading` matches if a method execution is in the trading module.
<3> `tradingOperation` matches if a method execution represents any public method in the
trading module.
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary",chomp="-packages"]
----
package com.xyz
class Pointcuts {
@Pointcut("execution(public * *(..))")
fun publicMethod() {} // <1>
@Pointcut("within(com.xyz.trading..*)")
fun inTrading() {} // <2>
@Pointcut("publicMethod() && inTrading()")
fun tradingOperation() {} // <3>
}
----
<1> `publicMethod` matches if a method execution join point represents the execution
of any public method.
<2> `inTrading` matches if a method execution is in the trading module.
<3> `tradingOperation` matches if a method execution represents any public method in the
trading module.
======
It is a best practice to build more complex pointcut expressions out of smaller _named
pointcuts_, as shown above. When referring to pointcuts by name, normal Java visibility
rules apply (you can see `private` pointcuts in the same type, `protected` pointcuts in
the hierarchy, `public` pointcuts anywhere, and so on). Visibility does not affect
pointcut matching.
[[aop-common-pointcuts]]
== Sharing Named Pointcut Definitions
When working with enterprise applications, developers often have the need to refer to
modules of the application and particular sets of operations from within several aspects.
We recommend defining a dedicated class that captures commonly used _named pointcut_
expressions for this purpose. Such a class typically resembles the following
`CommonPointcuts` example (though what you name the class is up to you):
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary",chomp="-packages",fold="none"]
----
package com.xyz;
import org.aspectj.lang.annotation.Pointcut;
public class CommonPointcuts {
/**
* A join point is in the web layer if the method is defined
* in a type in the com.xyz.web package or any sub-package
* under that.
*/
@Pointcut("within(com.xyz.web..*)")
public void inWebLayer() {}
/**
* A join point is in the service layer if the method is defined
* in a type in the com.xyz.service package or any sub-package
* under that.
*/
@Pointcut("within(com.xyz.service..*)")
public void inServiceLayer() {}
/**
* A join point is in the data access layer if the method is defined
* in a type in the com.xyz.dao package or any sub-package
* under that.
*/
@Pointcut("within(com.xyz.dao..*)")
public void inDataAccessLayer() {}
/**
* A business service is the execution of any method defined on a service
* interface. This definition assumes that interfaces are placed in the
* "service" package, and that implementation types are in sub-packages.
*
* If you group service interfaces by functional area (for example,
* in packages com.xyz.abc.service and com.xyz.def.service) then
* the pointcut expression "execution(* com.xyz..service.*.*(..))"
* could be used instead.
*
* Alternatively, you can write the expression using the 'bean'
* PCD, like so "bean(*Service)". (This assumes that you have
* named your Spring service beans in a consistent fashion.)
*/
@Pointcut("execution(* com.xyz..service.*.*(..))")
public void businessService() {}
/**
* A data access operation is the execution of any method defined on a
* DAO interface. This definition assumes that interfaces are placed in the
* "dao" package, and that implementation types are in sub-packages.
*/
@Pointcut("execution(* com.xyz.dao.*.*(..))")
public void dataAccessOperation() {}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary",chomp="-packages",fold="none"]
----
package com.xyz
import org.aspectj.lang.annotation.Pointcut
class CommonPointcuts {
/**
* A join point is in the web layer if the method is defined
* in a type in the com.xyz.web package or any sub-package
* under that.
*/
@Pointcut("within(com.xyz.web..*)")
fun inWebLayer() {}
/**
* A join point is in the service layer if the method is defined
* in a type in the com.xyz.service package or any sub-package
* under that.
*/
@Pointcut("within(com.xyz.service..*)")
fun inServiceLayer() {}
/**
* A join point is in the data access layer if the method is defined
* in a type in the com.xyz.dao package or any sub-package
* under that.
*/
@Pointcut("within(com.xyz.dao..*)")
fun inDataAccessLayer() {}
/**
* A business service is the execution of any method defined on a service
* interface. This definition assumes that interfaces are placed in the
* "service" package, and that implementation types are in sub-packages.
*
* If you group service interfaces by functional area (for example,
* in packages com.xyz.abc.service and com.xyz.def.service) then
* the pointcut expression "execution(* com.xyz..service.*.*(..))"
* could be used instead.
*
* Alternatively, you can write the expression using the 'bean'
* PCD, like so "bean(*Service)". (This assumes that you have
* named your Spring service beans in a consistent fashion.)
*/
@Pointcut("execution(* com.xyz..service.*.*(..))")
fun businessService() {}
/**
* A data access operation is the execution of any method defined on a
* DAO interface. This definition assumes that interfaces are placed in the
* "dao" package, and that implementation types are in sub-packages.
*/
@Pointcut("execution(* com.xyz.dao.*.*(..))")
fun dataAccessOperation() {}
}
----
======
You can refer to the pointcuts defined in such a class anywhere you need a pointcut
expression by referencing the fully-qualified name of the class combined with the
`@Pointcut` method's name. For example, to make the service layer transactional, you
could write the following which references the
`com.xyz.CommonPointcuts.businessService()` _named pointcut_:
[source,xml,indent=0,subs="verbatim"]
----
<aop:config>
<aop:advisor
pointcut="com.xyz.CommonPointcuts.businessService()"
advice-ref="tx-advice"/>
</aop:config>
<tx:advice id="tx-advice">
<tx:attributes>
<tx:method name="*" propagation="REQUIRED"/>
</tx:attributes>
</tx:advice>
----
The `<aop:config>` and `<aop:advisor>` elements are discussed in xref:core/aop/schema.adoc[Schema-based AOP Support]. The
transaction elements are discussed in xref:data-access/transaction.adoc[Transaction Management].
[[aop-pointcuts-examples]]
== Examples
Spring AOP users are likely to use the `execution` pointcut designator the most often.
The format of an execution expression follows:
[literal,indent=0,subs="verbatim"]
----
execution(modifiers-pattern?
ret-type-pattern
declaring-type-pattern?name-pattern(param-pattern)
throws-pattern?)
----
All parts except the returning type pattern (`ret-type-pattern` in the preceding snippet),
the name pattern, and the parameters pattern are optional. The returning type pattern determines
what the return type of the method must be in order for a join point to be matched.
`{asterisk}` is most frequently used as the returning type pattern. It matches any return
type. A fully-qualified type name matches only when the method returns the given
type. The name pattern matches the method name. You can use the `{asterisk}` wildcard as all or
part of a name pattern. If you specify a declaring type pattern,
include a trailing `.` to join it to the name pattern component.
The parameters pattern is slightly more complex: `()` matches a
method that takes no parameters, whereas `(..)` matches any number (zero or more) of parameters.
The `({asterisk})` pattern matches a method that takes one parameter of any type.
`(*,String)` matches a method that takes two parameters. The first can be of any type, while the
second must be a `String`. Consult the
{aspectj-docs-progguide}/semantics-pointcuts.html[Language
Semantics] section of the AspectJ Programming Guide for more information.
The following examples show some common pointcut expressions:
* The execution of any public method:
+
[literal,indent=0,subs="verbatim"]
----
execution(public * *(..))
----
* The execution of any method with a name that begins with `set`:
+
[literal,indent=0,subs="verbatim"]
----
execution(* set*(..))
----
* The execution of any method defined by the `AccountService` interface:
+
[literal,indent=0,subs="verbatim"]
----
execution(* com.xyz.service.AccountService.*(..))
----
* The execution of any method defined in the `service` package:
+
[literal,indent=0,subs="verbatim"]
----
execution(* com.xyz.service.*.*(..))
----
* The execution of any method defined in the service package or one of its sub-packages:
+
[literal,indent=0,subs="verbatim"]
----
execution(* com.xyz.service..*.*(..))
----
* Any join point (method execution only in Spring AOP) within the service package:
+
[literal,indent=0,subs="verbatim"]
----
within(com.xyz.service.*)
----
* Any join point (method execution only in Spring AOP) within the service package or one of its
sub-packages:
+
[literal,indent=0,subs="verbatim"]
----
within(com.xyz.service..*)
----
* Any join point (method execution only in Spring AOP) where the proxy implements the
`AccountService` interface:
+
[literal,indent=0,subs="verbatim"]
----
this(com.xyz.service.AccountService)
----
+
NOTE: `this` is more commonly used in a binding form. See the section on xref:core/aop/ataspectj/advice.adoc[Declaring Advice]
for how to make the proxy object available in the advice body.
* Any join point (method execution only in Spring AOP) where the target object
implements the `AccountService` interface:
+
[literal,indent=0,subs="verbatim"]
----
target(com.xyz.service.AccountService)
----
+
NOTE: `target` is more commonly used in a binding form. See the xref:core/aop/ataspectj/advice.adoc[Declaring Advice] section
for how to make the target object available in the advice body.
* Any join point (method execution only in Spring AOP) that takes a single parameter
and where the argument passed at runtime is `Serializable`:
+
[literal,indent=0,subs="verbatim"]
----
args(java.io.Serializable)
----
+
NOTE: `args` is more commonly used in a binding form. See the xref:core/aop/ataspectj/advice.adoc[Declaring Advice] section
for how to make the method arguments available in the advice body.
+
Note that the pointcut given in this example is different from `execution(*
*(java.io.Serializable))`. The args version matches if the argument passed at runtime is
`Serializable`, and the execution version matches if the method signature declares a single
parameter of type `Serializable`.
* Any join point (method execution only in Spring AOP) where the target object has a
`@Transactional` annotation:
+
[literal,indent=0,subs="verbatim"]
----
@target(org.springframework.transaction.annotation.Transactional)
----
+
NOTE: You can also use `@target` in a binding form. See the xref:core/aop/ataspectj/advice.adoc[Declaring Advice] section for
how to make the annotation object available in the advice body.
* Any join point (method execution only in Spring AOP) where the declared type of the
target object has an `@Transactional` annotation:
+
[literal,indent=0,subs="verbatim"]
----
@within(org.springframework.transaction.annotation.Transactional)
----
+
NOTE: You can also use `@within` in a binding form. See the xref:core/aop/ataspectj/advice.adoc[Declaring Advice] section for
how to make the annotation object available in the advice body.
* Any join point (method execution only in Spring AOP) where the executing method has an
`@Transactional` annotation:
+
[literal,indent=0,subs="verbatim"]
----
@annotation(org.springframework.transaction.annotation.Transactional)
----
+
NOTE: You can also use `@annotation` in a binding form. See the xref:core/aop/ataspectj/advice.adoc[Declaring Advice] section
for how to make the annotation object available in the advice body.
* Any join point (method execution only in Spring AOP) which takes a single parameter,
and where the runtime type of the argument passed has the `@Classified` annotation:
+
[literal,indent=0,subs="verbatim"]
----
@args(com.xyz.security.Classified)
----
+
NOTE: You can also use `@args` in a binding form. See the xref:core/aop/ataspectj/advice.adoc[Declaring Advice] section
how to make the annotation object(s) available in the advice body.
* Any join point (method execution only in Spring AOP) on a Spring bean named
`tradeService`:
+
[literal,indent=0,subs="verbatim"]
----
bean(tradeService)
----
* Any join point (method execution only in Spring AOP) on Spring beans having names that
match the wildcard expression `*Service`:
+
[literal,indent=0,subs="verbatim"]
----
bean(*Service)
----
[[writing-good-pointcuts]]
== Writing Good Pointcuts
During compilation, AspectJ processes pointcuts in order to optimize matching
performance. Examining code and determining if each join point matches (statically or
dynamically) a given pointcut is a costly process. (A dynamic match means the match
cannot be fully determined from static analysis and that a test is placed in the code to
determine if there is an actual match when the code is running). On first encountering a
pointcut declaration, AspectJ rewrites it into an optimal form for the matching
process. What does this mean? Basically, pointcuts are rewritten in DNF (Disjunctive
Normal Form) and the components of the pointcut are sorted such that those components
that are cheaper to evaluate are checked first. This means you do not have to worry
about understanding the performance of various pointcut designators and may supply them
in any order in a pointcut declaration.
However, AspectJ can work only with what it is told. For optimal performance of
matching, you should think about what you are trying to achieve and narrow the search
space for matches as much as possible in the definition. The existing designators
naturally fall into one of three groups: kinded, scoping, and contextual:
* Kinded designators select a particular kind of join point:
`execution`, `get`, `set`, `call`, and `handler`.
* Scoping designators select a group of join points of interest
(probably of many kinds): `within` and `withincode`
* Contextual designators match (and optionally bind) based on context:
`this`, `target`, and `@annotation`
A well written pointcut should include at least the first two types (kinded and
scoping). You can include the contextual designators to match based on
join point context or bind that context for use in the advice. Supplying only a
kinded designator or only a contextual designator works but could affect weaving
performance (time and memory used), due to extra processing and analysis. Scoping
designators are very fast to match, and using them means AspectJ can very quickly
dismiss groups of join points that should not be further processed. A good
pointcut should always include one if possible.
@@ -1,113 +0,0 @@
[[aop-choosing]]
= Choosing which AOP Declaration Style to Use
Once you have decided that an aspect is the best approach for implementing a given
requirement, how do you decide between using Spring AOP or AspectJ and between the
Aspect language (code) style, the @AspectJ annotation style, or the Spring XML style? These
decisions are influenced by a number of factors including application requirements,
development tools, and team familiarity with AOP.
[[aop-spring-or-aspectj]]
== Spring AOP or Full AspectJ?
Use the simplest thing that can work. Spring AOP is simpler than using full AspectJ, as
there is no requirement to introduce the AspectJ compiler / weaver into your development
and build processes. If you only need to advise the execution of operations on Spring
beans, Spring AOP is the right choice. If you need to advise objects not managed by
the Spring container (such as domain objects, typically), you need to use
AspectJ. You also need to use AspectJ if you wish to advise join points other than
simple method executions (for example, field get or set join points and so on).
When you use AspectJ, you have the choice of the AspectJ language syntax (also known as
the "code style") or the @AspectJ annotation style. If aspects play a large
role in your design, and you are able to use the https://www.eclipse.org/ajdt/[AspectJ
Development Tools (AJDT)] plugin for Eclipse, the AspectJ language syntax is the
preferred option. It is cleaner and simpler because the language was purposefully
designed for writing aspects. If you do not use Eclipse or have only a few aspects
that do not play a major role in your application, you may want to consider using
the @AspectJ style, sticking with regular Java compilation in your IDE, and adding
an aspect weaving phase to your build script.
[[aop-ataspectj-or-xml]]
== @AspectJ or XML for Spring AOP?
If you have chosen to use Spring AOP, you have a choice of @AspectJ or XML style.
There are various tradeoffs to consider.
The XML style may be most familiar to existing Spring users, and it is backed by genuine
POJOs. When using AOP as a tool to configure enterprise services, XML can be a good
choice (a good test is whether you consider the pointcut expression to be a part of your
configuration that you might want to change independently). With the XML style, it is
arguably clearer from your configuration which aspects are present in the system.
The XML style has two disadvantages. First, it does not fully encapsulate the
implementation of the requirement it addresses in a single place. The DRY principle says
that there should be a single, unambiguous, authoritative representation of any piece of
knowledge within a system. When using the XML style, the knowledge of how a requirement
is implemented is split across the declaration of the backing bean class and the XML in
the configuration file. When you use the @AspectJ style, this information is encapsulated
in a single module: the aspect. Secondly, the XML style is slightly more limited in what
it can express than the @AspectJ style: Only the "singleton" aspect instantiation model
is supported, and it is not possible to combine named pointcuts declared in XML.
For example, in the @AspectJ style you can write something like the following:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
@Pointcut("execution(* get*())")
public void propertyAccess() {}
@Pointcut("execution(com.xyz.Account+ *(..))")
public void operationReturningAnAccount() {}
@Pointcut("propertyAccess() && operationReturningAnAccount()")
public void accountPropertyAccess() {}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
@Pointcut("execution(* get*())")
fun propertyAccess() {}
@Pointcut("execution(com.xyz.Account+ *(..))")
fun operationReturningAnAccount() {}
@Pointcut("propertyAccess() && operationReturningAnAccount()")
fun accountPropertyAccess() {}
----
======
In the XML style you can declare the first two pointcuts:
[source,xml,indent=0,subs="verbatim"]
----
<aop:pointcut id="propertyAccess"
expression="execution(* get*())"/>
<aop:pointcut id="operationReturningAnAccount"
expression="execution(com.xyz.Account+ *(..))"/>
----
The downside of the XML approach is that you cannot define the
`accountPropertyAccess` pointcut by combining these definitions.
The @AspectJ style supports additional instantiation models and richer pointcut
composition. It has the advantage of keeping the aspect as a modular unit. It also has
the advantage that the @AspectJ aspects can be understood (and thus consumed) both by
Spring AOP and by AspectJ. So, if you later decide you need the capabilities of AspectJ
to implement additional requirements, you can easily migrate to a classic AspectJ setup.
In general, the Spring team prefers the @AspectJ style for custom aspects beyond simple
configuration of enterprise services.
@@ -1,79 +0,0 @@
[[aop-introduction-defn]]
= AOP Concepts
Let us begin by defining some central AOP concepts and terminology. These terms are not
Spring-specific. Unfortunately, AOP terminology is not particularly intuitive.
However, it would be even more confusing if Spring used its own terminology.
* Aspect: A modularization of a concern that cuts across multiple classes.
Transaction management is a good example of a crosscutting concern in enterprise Java
applications. In Spring AOP, aspects are implemented by using regular classes
(the xref:core/aop/schema.adoc[schema-based approach]) or regular classes annotated with the
`@Aspect` annotation (the xref:core/aop/ataspectj.adoc[@AspectJ style]).
* Join point: A point during the execution of a program, such as the execution of a
method or the handling of an exception. In Spring AOP, a join point always
represents a method execution.
* Advice: Action taken by an aspect at a particular join point. Different types of
advice include "around", "before", and "after" advice. (Advice types are discussed
later.) Many AOP frameworks, including Spring, model an advice as an interceptor and
maintain a chain of interceptors around the join point.
* Pointcut: A predicate that matches join points. Advice is associated with a
pointcut expression and runs at any join point matched by the pointcut (for example,
the execution of a method with a certain name). The concept of join points as matched
by pointcut expressions is central to AOP, and Spring uses the AspectJ pointcut
expression language by default.
* Introduction: Declaring additional methods or fields on behalf of a type. Spring
AOP lets you introduce new interfaces (and a corresponding implementation) to any
advised object. For example, you could use an introduction to make a bean implement an
`IsModified` interface, to simplify caching. (An introduction is known as an
inter-type declaration in the AspectJ community.)
* Target object: An object being advised by one or more aspects. Also referred to as
the "advised object". Since Spring AOP is implemented by using runtime proxies, this
object is always a proxied object.
* AOP proxy: An object created by the AOP framework in order to implement the aspect
contracts (advice method executions and so on). In the Spring Framework, an AOP proxy
is a JDK dynamic proxy or a CGLIB proxy.
* Weaving: linking aspects with other application types or objects to create an
advised object. This can be done at compile time (using the AspectJ compiler, for
example), load time, or at runtime. Spring AOP, like other pure Java AOP frameworks,
performs weaving at runtime.
Spring AOP includes the following types of advice:
* Before advice: Advice that runs before a join point but that does not have
the ability to prevent execution flow proceeding to the join point (unless it throws
an exception).
* After returning advice: Advice to be run after a join point completes
normally (for example, if a method returns without throwing an exception).
* After throwing advice: Advice to be run if a method exits by throwing an
exception.
* After (finally) advice: Advice to be run regardless of the means by which a
join point exits (normal or exceptional return).
* Around advice: Advice that surrounds a join point such as a method invocation.
This is the most powerful kind of advice. Around advice can perform custom behavior
before and after the method invocation. It is also responsible for choosing whether to
proceed to the join point or to shortcut the advised method execution by returning its
own return value or throwing an exception.
Around advice is the most general kind of advice. Since Spring AOP, like AspectJ,
provides a full range of advice types, we recommend that you use the least powerful
advice type that can implement the required behavior. For example, if you need only to
update a cache with the return value of a method, you are better off implementing an
after returning advice than an around advice, although an around advice can accomplish
the same thing. Using the most specific advice type provides a simpler programming model
with less potential for errors. For example, you do not need to invoke the `proceed()`
method on the `JoinPoint` used for around advice, and, hence, you cannot fail to invoke it.
All advice parameters are statically typed so that you work with advice parameters of
the appropriate type (e.g. the type of the return value from a method execution) rather
than `Object` arrays.
The concept of join points matched by pointcuts is the key to AOP, which distinguishes
it from older technologies offering only interception. Pointcuts enable advice to be
targeted independently of the object-oriented hierarchy. For example, you can apply an
around advice providing declarative transaction management to a set of methods that span
multiple objects (such as all business operations in the service layer).
@@ -1,22 +0,0 @@
[[aop-introduction-proxies]]
= AOP Proxies
:page-section-summary-toc: 1
Spring AOP defaults to using standard JDK dynamic proxies for AOP proxies. This
enables any interface (or set of interfaces) to be proxied.
Spring AOP can also use CGLIB proxies. This is necessary to proxy classes rather than
interfaces. By default, CGLIB is used if a business object does not implement an
interface. As it is good practice to program to interfaces rather than classes, business
classes normally implement one or more business interfaces. It is possible to
xref:core/aop/proxying.adoc[force the use of CGLIB], in those (hopefully rare) cases where you
need to advise a method that is not declared on an interface or where you need to
pass a proxied object to a method as a concrete type.
It is important to grasp the fact that Spring AOP is proxy-based. See
xref:core/aop/proxying.adoc#aop-understanding-aop-proxies[Understanding AOP Proxies] for a thorough examination of exactly what this
implementation detail actually means.
@@ -1,61 +0,0 @@
[[aop-introduction-spring-defn]]
= Spring AOP Capabilities and Goals
Spring AOP is implemented in pure Java. There is no need for a special compilation
process. Spring AOP does not need to control the class loader hierarchy and is thus
suitable for use in a servlet container or application server.
Spring AOP currently supports only method execution join points (advising the execution
of methods on Spring beans). Field interception is not implemented, although support for
field interception could be added without breaking the core Spring AOP APIs. If you need
to advise field access and update join points, consider a language such as AspectJ.
Spring AOP's approach to AOP differs from that of most other AOP frameworks. The aim is
not to provide the most complete AOP implementation (although Spring AOP is quite
capable). Rather, the aim is to provide a close integration between AOP implementation and
Spring IoC, to help solve common problems in enterprise applications.
Thus, for example, the Spring Framework's AOP functionality is normally used in
conjunction with the Spring IoC container. Aspects are configured by using normal bean
definition syntax (although this allows powerful "auto-proxying" capabilities). This is a
crucial difference from other AOP implementations. You cannot do some things
easily or efficiently with Spring AOP, such as advise very fine-grained objects (typically,
domain objects). AspectJ is the best choice in such cases. However, our
experience is that Spring AOP provides an excellent solution to most problems in
enterprise Java applications that are amenable to AOP.
Spring AOP never strives to compete with AspectJ to provide a comprehensive AOP
solution. We believe that both proxy-based frameworks such as Spring AOP and full-blown
frameworks such as AspectJ are valuable and that they are complementary, rather than in
competition. Spring seamlessly integrates Spring AOP and IoC with AspectJ, to enable
all uses of AOP within a consistent Spring-based application
architecture. This integration does not affect the Spring AOP API or the AOP Alliance
API. Spring AOP remains backward-compatible. See xref:core/aop-api.adoc[the following chapter]
for a discussion of the Spring AOP APIs.
[NOTE]
====
One of the central tenets of the Spring Framework is that of non-invasiveness. This
is the idea that you should not be forced to introduce framework-specific classes and
interfaces into your business or domain model. However, in some places, the Spring Framework
does give you the option to introduce Spring Framework-specific dependencies into your
codebase. The rationale in giving you such options is because, in certain scenarios, it
might be just plain easier to read or code some specific piece of functionality in such
a way. However, the Spring Framework (almost) always offers you the choice: You have the
freedom to make an informed decision as to which option best suits your particular use
case or scenario.
One such choice that is relevant to this chapter is that of which AOP framework (and
which AOP style) to choose. You have the choice of AspectJ, Spring AOP, or both. You
also have the choice of either the @AspectJ annotation-style approach or the Spring XML
configuration-style approach. The fact that this chapter chooses to introduce the
@AspectJ-style approach first should not be taken as an indication that the Spring team
favors the @AspectJ annotation-style approach over the Spring XML configuration-style.
See xref:core/aop/choosing.adoc[Choosing which AOP Declaration Style to Use] for a more complete discussion of the advantages and disadvantages of
each style.
====
@@ -1,12 +0,0 @@
[[aop-mixing-styles]]
= Mixing Aspect Types
:page-section-summary-toc: 1
It is perfectly possible to mix @AspectJ style aspects by using the auto-proxying support,
schema-defined `<aop:aspect>` aspects, `<aop:advisor>` declared advisors, and even proxies
and interceptors in other styles in the same configuration. All of these are implemented
by using the same underlying support mechanism and can co-exist without any difficulty.
@@ -1,281 +0,0 @@
[[aop-proxying]]
= Proxying Mechanisms
Spring AOP uses either JDK dynamic proxies or CGLIB to create the proxy for a given
target object. JDK dynamic proxies are built into the JDK, whereas CGLIB is a common
open-source class definition library (repackaged into `spring-core`).
If the target object to be proxied implements at least one interface, a JDK dynamic
proxy is used. All of the interfaces implemented by the target type are proxied.
If the target object does not implement any interfaces, a CGLIB proxy is created.
If you want to force the use of CGLIB proxying (for example, to proxy every method
defined for the target object, not only those implemented by its interfaces),
you can do so. However, you should consider the following issues:
* With CGLIB, `final` methods cannot be advised, as they cannot be overridden in
runtime-generated subclasses.
* As of Spring 4.0, the constructor of your proxied object is NOT called twice anymore,
since the CGLIB proxy instance is created through Objenesis. Only if your JVM does
not allow for constructor bypassing, you might see double invocations and
corresponding debug log entries from Spring's AOP support.
To force the use of CGLIB proxies, set the value of the `proxy-target-class` attribute
of the `<aop:config>` element to true, as follows:
[source,xml,indent=0,subs="verbatim"]
----
<aop:config proxy-target-class="true">
<!-- other beans defined here... -->
</aop:config>
----
To force CGLIB proxying when you use the @AspectJ auto-proxy support, set the
`proxy-target-class` attribute of the `<aop:aspectj-autoproxy>` element to `true`,
as follows:
[source,xml,indent=0,subs="verbatim"]
----
<aop:aspectj-autoproxy proxy-target-class="true"/>
----
[NOTE]
====
Multiple `<aop:config/>` sections are collapsed into a single unified auto-proxy creator
at runtime, which applies the _strongest_ proxy settings that any of the
`<aop:config/>` sections (typically from different XML bean definition files) specified.
This also applies to the `<tx:annotation-driven/>` and `<aop:aspectj-autoproxy/>`
elements.
To be clear, using `proxy-target-class="true"` on `<tx:annotation-driven/>`,
`<aop:aspectj-autoproxy/>`, or `<aop:config/>` elements forces the use of CGLIB
proxies _for all three of them_.
====
[[aop-understanding-aop-proxies]]
== Understanding AOP Proxies
Spring AOP is proxy-based. It is vitally important that you grasp the semantics of
what that last statement actually means before you write your own aspects or use any of
the Spring AOP-based aspects supplied with the Spring Framework.
Consider first the scenario where you have a plain-vanilla, un-proxied,
nothing-special-about-it, straight object reference, as the following
code snippet shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
public class SimplePojo implements Pojo {
public void foo() {
// this next method invocation is a direct call on the 'this' reference
this.bar();
}
public void bar() {
// some logic...
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
class SimplePojo : Pojo {
fun foo() {
// this next method invocation is a direct call on the 'this' reference
this.bar()
}
fun bar() {
// some logic...
}
}
----
======
If you invoke a method on an object reference, the method is invoked directly on
that object reference, as the following image and listing show:
image::aop-proxy-plain-pojo-call.png[]
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
public class Main {
public static void main(String[] args) {
Pojo pojo = new SimplePojo();
// this is a direct method call on the 'pojo' reference
pojo.foo();
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
fun main() {
val pojo = SimplePojo()
// this is a direct method call on the 'pojo' reference
pojo.foo()
}
----
======
Things change slightly when the reference that client code has is a proxy. Consider the
following diagram and code snippet:
image::aop-proxy-call.png[]
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
public class Main {
public static void main(String[] args) {
ProxyFactory factory = new ProxyFactory(new SimplePojo());
factory.addInterface(Pojo.class);
factory.addAdvice(new RetryAdvice());
Pojo pojo = (Pojo) factory.getProxy();
// this is a method call on the proxy!
pojo.foo();
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
fun main() {
val factory = ProxyFactory(SimplePojo())
factory.addInterface(Pojo::class.java)
factory.addAdvice(RetryAdvice())
val pojo = factory.proxy as Pojo
// this is a method call on the proxy!
pojo.foo()
}
----
======
The key thing to understand here is that the client code inside the `main(..)` method
of the `Main` class has a reference to the proxy. This means that method calls on that
object reference are calls on the proxy. As a result, the proxy can delegate to all of
the interceptors (advice) that are relevant to that particular method call. However,
once the call has finally reached the target object (the `SimplePojo` reference in
this case), any method calls that it may make on itself, such as `this.bar()` or
`this.foo()`, are going to be invoked against the `this` reference, and not the proxy.
This has important implications. It means that self-invocation is not going to result
in the advice associated with a method invocation getting a chance to run.
Okay, so what is to be done about this? The best approach (the term "best" is used
loosely here) is to refactor your code such that the self-invocation does not happen.
This does entail some work on your part, but it is the best, least-invasive approach.
The next approach is absolutely horrendous, and we hesitate to point it out, precisely
because it is so horrendous. You can (painful as it is to us) totally tie the logic
within your class to Spring AOP, as the following example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
public class SimplePojo implements Pojo {
public void foo() {
// this works, but... gah!
((Pojo) AopContext.currentProxy()).bar();
}
public void bar() {
// some logic...
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
class SimplePojo : Pojo {
fun foo() {
// this works, but... gah!
(AopContext.currentProxy() as Pojo).bar()
}
fun bar() {
// some logic...
}
}
----
======
This totally couples your code to Spring AOP, and it makes the class itself aware of
the fact that it is being used in an AOP context, which flies in the face of AOP. It
also requires some additional configuration when the proxy is being created, as the
following example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
public class Main {
public static void main(String[] args) {
ProxyFactory factory = new ProxyFactory(new SimplePojo());
factory.addInterface(Pojo.class);
factory.addAdvice(new RetryAdvice());
factory.setExposeProxy(true);
Pojo pojo = (Pojo) factory.getProxy();
// this is a method call on the proxy!
pojo.foo();
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
fun main() {
val factory = ProxyFactory(SimplePojo())
factory.addInterface(Pojo::class.java)
factory.addAdvice(RetryAdvice())
factory.isExposeProxy = true
val pojo = factory.proxy as Pojo
// this is a method call on the proxy!
pojo.foo()
}
----
======
Finally, it must be noted that AspectJ does not have this self-invocation issue because
it is not a proxy-based AOP framework.
@@ -1,12 +0,0 @@
[[aop-resources]]
= Further Resources
:page-section-summary-toc: 1
More information on AspectJ can be found on the {aspectj-site}[AspectJ website].
_Eclipse AspectJ_ by Adrian Colyer et. al. (Addison-Wesley, 2005) provides a
comprehensive introduction and reference for the AspectJ language.
_AspectJ in Action_, Second Edition by Ramnivas Laddad (Manning, 2009) comes highly
recommended. The focus of the book is on AspectJ, but a lot of general AOP themes are
explored (in some depth).
@@ -1,987 +0,0 @@
[[aop-schema]]
= Schema-based AOP Support
If you prefer an XML-based format, Spring also offers support for defining aspects
using the `aop` namespace tags. The exact same pointcut expressions and advice kinds
as when using the @AspectJ style are supported. Hence, in this section we focus on
that syntax and refer the reader to the discussion in the previous section
(xref:core/aop/ataspectj.adoc[@AspectJ support]) for an understanding of writing pointcut expressions and the binding
of advice parameters.
To use the aop namespace tags described in this section, you need to import the
`spring-aop` schema, as described in xref:core/appendix/xsd-schemas.adoc[XML Schema-based configuration]
. See xref:core/appendix/xsd-schemas.adoc#aop[the AOP schema]
for how to import the tags in the `aop` namespace.
Within your Spring configurations, all aspect and advisor elements must be placed within
an `<aop:config>` element (you can have more than one `<aop:config>` element in an
application context configuration). An `<aop:config>` element can contain pointcut,
advisor, and aspect elements (note that these must be declared in that order).
WARNING: The `<aop:config>` style of configuration makes heavy use of Spring's
xref:core/aop-api/autoproxy.adoc[auto-proxying] mechanism. This can cause issues (such as advice
not being woven) if you already use explicit auto-proxying through the use of
`BeanNameAutoProxyCreator` or something similar. The recommended usage pattern is to
use either only the `<aop:config>` style or only the `AutoProxyCreator` style and
never mix them.
[[aop-schema-declaring-an-aspect]]
== Declaring an Aspect
When you use the schema support, an aspect is a regular Java object defined as a bean in
your Spring application context. The state and behavior are captured in the fields and
methods of the object, and the pointcut and advice information are captured in the XML.
You can declare an aspect by using the `<aop:aspect>` element, and reference the backing bean
by using the `ref` attribute, as the following example shows:
[source,xml,indent=0,subs="verbatim"]
----
<aop:config>
<aop:aspect id="myAspect" ref="aBean">
...
</aop:aspect>
</aop:config>
<bean id="aBean" class="...">
...
</bean>
----
The bean that backs the aspect (`aBean` in this case) can of course be configured and
dependency injected just like any other Spring bean.
[[aop-schema-pointcuts]]
== Declaring a Pointcut
You can declare a _named pointcut_ inside an `<aop:config>` element, letting the pointcut
definition be shared across several aspects and advisors.
A pointcut that represents the execution of any business service in the service layer can
be defined as follows:
[source,xml,indent=0,subs="verbatim"]
----
<aop:config>
<aop:pointcut id="businessService"
expression="execution(* com.xyz.service.*.*(..))" />
</aop:config>
----
Note that the pointcut expression itself uses the same AspectJ pointcut expression
language as described in xref:core/aop/ataspectj.adoc[@AspectJ support]. If you use the schema based declaration
style, you can also refer to _named pointcuts_ defined in `@Aspect` types within the
pointcut expression. Thus, another way of defining the above pointcut would be as follows:
[source,xml,indent=0,subs="verbatim"]
----
<aop:config>
<aop:pointcut id="businessService"
expression="com.xyz.CommonPointcuts.businessService()" /> <1>
</aop:config>
----
<1> References the `businessService` named pointcut defined in xref:core/aop/ataspectj/pointcuts.adoc#aop-common-pointcuts[Sharing Named Pointcut Definitions].
Declaring a pointcut _inside_ an aspect is very similar to declaring a top-level pointcut,
as the following example shows:
[source,xml,indent=0,subs="verbatim"]
----
<aop:config>
<aop:aspect id="myAspect" ref="aBean">
<aop:pointcut id="businessService"
expression="execution(* com.xyz.service.*.*(..))"/>
...
</aop:aspect>
</aop:config>
----
In much the same way as an @AspectJ aspect, pointcuts declared by using the schema based
definition style can collect join point context. For example, the following pointcut
collects the `this` object as the join point context and passes it to the advice:
[source,xml,indent=0,subs="verbatim"]
----
<aop:config>
<aop:aspect id="myAspect" ref="aBean">
<aop:pointcut id="businessService"
expression="execution(* com.xyz.service.*.*(..)) &amp;&amp; this(service)"/>
<aop:before pointcut-ref="businessService" method="monitor"/>
...
</aop:aspect>
</aop:config>
----
The advice must be declared to receive the collected join point context by including
parameters of the matching names, as follows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
public void monitor(Object service) {
// ...
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
fun monitor(service: Any) {
// ...
}
----
======
When combining pointcut sub-expressions, `+&amp;&amp;+` is awkward within an XML
document, so you can use the `and`, `or`, and `not` keywords in place of `+&amp;&amp;+`,
`||`, and `!`, respectively. For example, the previous pointcut can be better written as
follows:
[source,xml,indent=0,subs="verbatim"]
----
<aop:config>
<aop:aspect id="myAspect" ref="aBean">
<aop:pointcut id="businessService"
expression="execution(* com.xyz.service.*.*(..)) and this(service)"/>
<aop:before pointcut-ref="businessService" method="monitor"/>
...
</aop:aspect>
</aop:config>
----
Note that pointcuts defined in this way are referred to by their XML `id` and cannot be
used as named pointcuts to form composite pointcuts. The named pointcut support in the
schema-based definition style is thus more limited than that offered by the @AspectJ
style.
[[aop-schema-advice]]
== Declaring Advice
The schema-based AOP support uses the same five kinds of advice as the @AspectJ style, and they have
exactly the same semantics.
[[aop-schema-advice-before]]
=== Before Advice
Before advice runs before a matched method execution. It is declared inside an
`<aop:aspect>` by using the `<aop:before>` element, as the following example shows:
[source,xml,indent=0,subs="verbatim"]
----
<aop:aspect id="beforeExample" ref="aBean">
<aop:before
pointcut-ref="dataAccessOperation"
method="doAccessCheck"/>
...
</aop:aspect>
----
In the example above, `dataAccessOperation` is the `id` of a _named pointcut_ defined at
the top (`<aop:config>`) level (see xref:core/aop/schema.adoc#aop-schema-pointcuts[Declaring a Pointcut]).
NOTE: As we noted in the discussion of the @AspectJ style, using _named pointcuts_ can
significantly improve the readability of your code. See xref:core/aop/ataspectj/pointcuts.adoc#aop-common-pointcuts[Sharing Named Pointcut Definitions] for
details.
To define the pointcut inline instead, replace the `pointcut-ref` attribute with a
`pointcut` attribute, as follows:
[source,xml,indent=0,subs="verbatim"]
----
<aop:aspect id="beforeExample" ref="aBean">
<aop:before
pointcut="execution(* com.xyz.dao.*.*(..))"
method="doAccessCheck"/>
...
</aop:aspect>
----
The `method` attribute identifies a method (`doAccessCheck`) that provides the body of
the advice. This method must be defined for the bean referenced by the aspect element
that contains the advice. Before a data access operation is performed (a method execution
join point matched by the pointcut expression), the `doAccessCheck` method on the aspect
bean is invoked.
[[aop-schema-advice-after-returning]]
=== After Returning Advice
After returning advice runs when a matched method execution completes normally. It is
declared inside an `<aop:aspect>` in the same way as before advice. The following example
shows how to declare it:
[source,xml,indent=0,subs="verbatim"]
----
<aop:aspect id="afterReturningExample" ref="aBean">
<aop:after-returning
pointcut="execution(* com.xyz.dao.*.*(..))"
method="doAccessCheck"/>
...
</aop:aspect>
----
As in the @AspectJ style, you can get the return value within the advice body.
To do so, use the `returning` attribute to specify the name of the parameter to which
the return value should be passed, as the following example shows:
[source,xml,indent=0,subs="verbatim"]
----
<aop:aspect id="afterReturningExample" ref="aBean">
<aop:after-returning
pointcut="execution(* com.xyz.dao.*.*(..))"
returning="retVal"
method="doAccessCheck"/>
...
</aop:aspect>
----
The `doAccessCheck` method must declare a parameter named `retVal`. The type of this
parameter constrains matching in the same way as described for `@AfterReturning`. For
example, you can declare the method signature as follows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
public void doAccessCheck(Object retVal) {...
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
fun doAccessCheck(retVal: Any) {...
----
======
[[aop-schema-advice-after-throwing]]
=== After Throwing Advice
After throwing advice runs when a matched method execution exits by throwing an
exception. It is declared inside an `<aop:aspect>` by using the `after-throwing` element,
as the following example shows:
[source,xml,indent=0,subs="verbatim"]
----
<aop:aspect id="afterThrowingExample" ref="aBean">
<aop:after-throwing
pointcut="execution(* com.xyz.dao.*.*(..))"
method="doRecoveryActions"/>
...
</aop:aspect>
----
As in the @AspectJ style, you can get the thrown exception within the advice body.
To do so, use the `throwing` attribute to specify the name of the parameter to
which the exception should be passed as the following example shows:
[source,xml,indent=0,subs="verbatim"]
----
<aop:aspect id="afterThrowingExample" ref="aBean">
<aop:after-throwing
pointcut="execution(* com.xyz.dao.*.*(..))"
throwing="dataAccessEx"
method="doRecoveryActions"/>
...
</aop:aspect>
----
The `doRecoveryActions` method must declare a parameter named `dataAccessEx`.
The type of this parameter constrains matching in the same way as described for
`@AfterThrowing`. For example, the method signature may be declared as follows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
public void doRecoveryActions(DataAccessException dataAccessEx) {...
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
fun doRecoveryActions(dataAccessEx: DataAccessException) {...
----
======
[[aop-schema-advice-after-finally]]
=== After (Finally) Advice
After (finally) advice runs no matter how a matched method execution exits.
You can declare it by using the `after` element, as the following example shows:
[source,xml,indent=0,subs="verbatim"]
----
<aop:aspect id="afterFinallyExample" ref="aBean">
<aop:after
pointcut="execution(* com.xyz.dao.*.*(..))"
method="doReleaseLock"/>
...
</aop:aspect>
----
[[aop-schema-advice-around]]
=== Around Advice
The last kind of advice is _around_ advice. Around advice runs "around" a matched
method's execution. It has the opportunity to do work both before and after the method
runs and to determine when, how, and even if the method actually gets to run at all.
Around advice is often used if you need to share state before and after a method
execution in a thread-safe manner for example, starting and stopping a timer.
[TIP]
====
Always use the least powerful form of advice that meets your requirements.
For example, do not use _around_ advice if _before_ advice is sufficient for your needs.
====
You can declare around advice by using the `aop:around` element. The advice method should
declare `Object` as its return type, and the first parameter of the method must be of
type `ProceedingJoinPoint`. Within the body of the advice method, you must invoke
`proceed()` on the `ProceedingJoinPoint` in order for the underlying method to run.
Invoking `proceed()` without arguments will result in the caller's original arguments
being supplied to the underlying method when it is invoked. For advanced use cases, there
is an overloaded variant of the `proceed()` method which accepts an array of arguments
(`Object[]`). The values in the array will be used as the arguments to the underlying
method when it is invoked. See xref:core/aop/ataspectj/advice.adoc#aop-ataspectj-around-advice[Around Advice] for notes on calling
`proceed` with an `Object[]`.
The following example shows how to declare around advice in XML:
[source,xml,indent=0,subs="verbatim"]
----
<aop:aspect id="aroundExample" ref="aBean">
<aop:around
pointcut="execution(* com.xyz.service.*.*(..))"
method="doBasicProfiling"/>
...
</aop:aspect>
----
The implementation of the `doBasicProfiling` advice can be exactly the same as in the
@AspectJ example (minus the annotation, of course), as the following example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
public Object doBasicProfiling(ProceedingJoinPoint pjp) throws Throwable {
// start stopwatch
Object retVal = pjp.proceed();
// stop stopwatch
return retVal;
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
fun doBasicProfiling(pjp: ProceedingJoinPoint): Any? {
// start stopwatch
val retVal = pjp.proceed()
// stop stopwatch
return pjp.proceed()
}
----
======
[[aop-schema-params]]
=== Advice Parameters
The schema-based declaration style supports fully typed advice in the same way as
described for the @AspectJ support -- by matching pointcut parameters by name against
advice method parameters. See xref:core/aop/ataspectj/advice.adoc#aop-ataspectj-advice-params[Advice Parameters] for details. If you wish
to explicitly specify argument names for the advice methods (not relying on the
detection strategies previously described), you can do so by using the `arg-names`
attribute of the advice element, which is treated in the same manner as the `argNames`
attribute in an advice annotation (as described in xref:core/aop/ataspectj/advice.adoc#aop-ataspectj-advice-params-names[Determining Argument Names]).
The following example shows how to specify an argument name in XML:
[source,xml,indent=0,subs="verbatim"]
----
<aop:before
pointcut="com.xyz.Pointcuts.publicMethod() and @annotation(auditable)" <1>
method="audit"
arg-names="auditable" />
----
<1> References the `publicMethod` named pointcut defined in xref:core/aop/ataspectj/pointcuts.adoc#aop-pointcuts-combining[Combining Pointcut Expressions].
The `arg-names` attribute accepts a comma-delimited list of parameter names.
The following slightly more involved example of the XSD-based approach shows
some around advice used in conjunction with a number of strongly typed parameters:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary",chomp="-packages"]
----
package com.xyz.service;
public interface PersonService {
Person getPerson(String personName, int age);
}
public class DefaultPersonService implements PersonService {
public Person getPerson(String name, int age) {
return new Person(name, age);
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary",chomp="-packages"]
----
package com.xyz.service
interface PersonService {
fun getPerson(personName: String, age: Int): Person
}
class DefaultPersonService : PersonService {
fun getPerson(name: String, age: Int): Person {
return Person(name, age)
}
}
----
======
Next up is the aspect. Notice the fact that the `profile(..)` method accepts a number of
strongly-typed parameters, the first of which happens to be the join point used to
proceed with the method call. The presence of this parameter is an indication that the
`profile(..)` is to be used as `around` advice, as the following example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary",chomp="-packages"]
----
package com.xyz;
import org.aspectj.lang.ProceedingJoinPoint;
import org.springframework.util.StopWatch;
public class SimpleProfiler {
public Object profile(ProceedingJoinPoint call, String name, int age) throws Throwable {
StopWatch clock = new StopWatch("Profiling for '" + name + "' and '" + age + "'");
try {
clock.start(call.toShortString());
return call.proceed();
} finally {
clock.stop();
System.out.println(clock.prettyPrint());
}
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary",chomp="-packages"]
----
package com.xyz
import org.aspectj.lang.ProceedingJoinPoint
import org.springframework.util.StopWatch
class SimpleProfiler {
fun profile(call: ProceedingJoinPoint, name: String, age: Int): Any? {
val clock = StopWatch("Profiling for '$name' and '$age'")
try {
clock.start(call.toShortString())
return call.proceed()
} finally {
clock.stop()
println(clock.prettyPrint())
}
}
}
----
======
Finally, the following example XML configuration effects the execution of the
preceding advice for a particular join point:
[source,xml,indent=0,subs="verbatim"]
----
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/aop
https://www.springframework.org/schema/aop/spring-aop.xsd">
<!-- this is the object that will be proxied by Spring's AOP infrastructure -->
<bean id="personService" class="com.xyz.service.DefaultPersonService"/>
<!-- this is the actual advice itself -->
<bean id="profiler" class="com.xyz.SimpleProfiler"/>
<aop:config>
<aop:aspect ref="profiler">
<aop:pointcut id="theExecutionOfSomePersonServiceMethod"
expression="execution(* com.xyz.service.PersonService.getPerson(String,int))
and args(name, age)"/>
<aop:around pointcut-ref="theExecutionOfSomePersonServiceMethod"
method="profile"/>
</aop:aspect>
</aop:config>
</beans>
----
Consider the following driver script:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
public class Boot {
public static void main(String[] args) {
ApplicationContext ctx = new ClassPathXmlApplicationContext("beans.xml");
PersonService person = ctx.getBean(PersonService.class);
person.getPerson("Pengo", 12);
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
fun main() {
val ctx = ClassPathXmlApplicationContext("beans.xml")
val person = ctx.getBean(PersonService.class)
person.getPerson("Pengo", 12)
}
----
======
With such a `Boot` class, we would get output similar to the following on standard output:
[literal,subs="verbatim"]
----
StopWatch 'Profiling for 'Pengo' and '12': running time (millis) = 0
-----------------------------------------
ms % Task name
-----------------------------------------
00000 ? execution(getFoo)
----
[[aop-ordering]]
=== Advice Ordering
When multiple pieces of advice need to run at the same join point (executing method)
the ordering rules are as described in xref:core/aop/ataspectj/advice.adoc#aop-ataspectj-advice-ordering[Advice Ordering]. The precedence
between aspects is determined via the `order` attribute in the `<aop:aspect>` element or
by either adding the `@Order` annotation to the bean that backs the aspect or by having
the bean implement the `Ordered` interface.
[NOTE]
====
In contrast to the precedence rules for advice methods defined in the same `@Aspect`
class, when two pieces of advice defined in the same `<aop:aspect>` element both need to
run at the same join point, the precedence is determined by the order in which the advice
elements are declared within the enclosing `<aop:aspect>` element, from highest to lowest
precedence.
For example, given an `around` advice and a `before` advice defined in the same
`<aop:aspect>` element that apply to the same join point, to ensure that the `around`
advice has higher precedence than the `before` advice, the `<aop:around>` element must be
declared before the `<aop:before>` element.
As a general rule of thumb, if you find that you have multiple pieces of advice defined
in the same `<aop:aspect>` element that apply to the same join point, consider collapsing
such advice methods into one advice method per join point in each `<aop:aspect>` element
or refactor the pieces of advice into separate `<aop:aspect>` elements that you can order
at the aspect level.
====
[[aop-schema-introductions]]
== Introductions
Introductions (known as inter-type declarations in AspectJ) let an aspect declare
that advised objects implement a given interface and provide an implementation of
that interface on behalf of those objects.
You can make an introduction by using the `aop:declare-parents` element inside an `aop:aspect`.
You can use the `aop:declare-parents` element to declare that matching types have a new parent (hence the name).
For example, given an interface named `UsageTracked` and an implementation of that interface named
`DefaultUsageTracked`, the following aspect declares that all implementors of service
interfaces also implement the `UsageTracked` interface. (In order to expose statistics
through JMX for example.)
[source,xml,indent=0,subs="verbatim"]
----
<aop:aspect id="usageTrackerAspect" ref="usageTracking">
<aop:declare-parents
types-matching="com.xyz.service.*+"
implement-interface="com.xyz.service.tracking.UsageTracked"
default-impl="com.xyz.service.tracking.DefaultUsageTracked"/>
<aop:before
pointcut="execution(* com.xyz..service.*.*(..))
and this(usageTracked)"
method="recordUsage"/>
</aop:aspect>
----
The class that backs the `usageTracking` bean would then contain the following method:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
public void recordUsage(UsageTracked usageTracked) {
usageTracked.incrementUseCount();
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
fun recordUsage(usageTracked: UsageTracked) {
usageTracked.incrementUseCount()
}
----
======
The interface to be implemented is determined by the `implement-interface` attribute. The
value of the `types-matching` attribute is an AspectJ type pattern. Any bean of a
matching type implements the `UsageTracked` interface. Note that, in the before
advice of the preceding example, service beans can be directly used as implementations of
the `UsageTracked` interface. To access a bean programmatically, you could write the
following:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
UsageTracked usageTracked = context.getBean("myService", UsageTracked.class);
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
val usageTracked = context.getBean("myService", UsageTracked.class)
----
======
[[aop-schema-instantiation-models]]
== Aspect Instantiation Models
The only supported instantiation model for schema-defined aspects is the singleton
model. Other instantiation models may be supported in future releases.
[[aop-schema-advisors]]
== Advisors
The concept of "advisors" comes from the AOP support defined in Spring
and does not have a direct equivalent in AspectJ. An advisor is like a small
self-contained aspect that has a single piece of advice. The advice itself is
represented by a bean and must implement one of the advice interfaces described in
xref:core/aop-api/advice.adoc#aop-api-advice-types[Advice Types in Spring]. Advisors can take advantage of AspectJ pointcut expressions.
Spring supports the advisor concept with the `<aop:advisor>` element. You most
commonly see it used in conjunction with transactional advice, which also has its own
namespace support in Spring. The following example shows an advisor:
[source,xml,indent=0,subs="verbatim"]
----
<aop:config>
<aop:pointcut id="businessService"
expression="execution(* com.xyz.service.*.*(..))"/>
<aop:advisor
pointcut-ref="businessService"
advice-ref="tx-advice" />
</aop:config>
<tx:advice id="tx-advice">
<tx:attributes>
<tx:method name="*" propagation="REQUIRED"/>
</tx:attributes>
</tx:advice>
----
As well as the `pointcut-ref` attribute used in the preceding example, you can also use the
`pointcut` attribute to define a pointcut expression inline.
To define the precedence of an advisor so that the advice can participate in ordering,
use the `order` attribute to define the `Ordered` value of the advisor.
[[aop-schema-example]]
== An AOP Schema Example
This section shows how the concurrent locking failure retry example from
xref:core/aop/ataspectj/example.adoc[An AOP Example] looks when rewritten with the schema support.
The execution of business services can sometimes fail due to concurrency issues (for
example, a deadlock loser). If the operation is retried, it is likely to succeed
on the next try. For business services where it is appropriate to retry in such
conditions (idempotent operations that do not need to go back to the user for conflict
resolution), we want to transparently retry the operation to avoid the client seeing a
`PessimisticLockingFailureException`. This is a requirement that clearly cuts across
multiple services in the service layer and, hence, is ideal for implementing through an
aspect.
Because we want to retry the operation, we need to use around advice so that we can
call `proceed` multiple times. The following listing shows the basic aspect implementation
(which is a regular Java class that uses the schema support):
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
public class ConcurrentOperationExecutor implements Ordered {
private static final int DEFAULT_MAX_RETRIES = 2;
private int maxRetries = DEFAULT_MAX_RETRIES;
private int order = 1;
public void setMaxRetries(int maxRetries) {
this.maxRetries = maxRetries;
}
public int getOrder() {
return this.order;
}
public void setOrder(int order) {
this.order = order;
}
public Object doConcurrentOperation(ProceedingJoinPoint pjp) throws Throwable {
int numAttempts = 0;
PessimisticLockingFailureException lockFailureException;
do {
numAttempts++;
try {
return pjp.proceed();
}
catch(PessimisticLockingFailureException ex) {
lockFailureException = ex;
}
} while(numAttempts <= this.maxRetries);
throw lockFailureException;
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
class ConcurrentOperationExecutor : Ordered {
private val DEFAULT_MAX_RETRIES = 2
private var maxRetries = DEFAULT_MAX_RETRIES
private var order = 1
fun setMaxRetries(maxRetries: Int) {
this.maxRetries = maxRetries
}
override fun getOrder(): Int {
return this.order
}
fun setOrder(order: Int) {
this.order = order
}
fun doConcurrentOperation(pjp: ProceedingJoinPoint): Any? {
var numAttempts = 0
var lockFailureException: PessimisticLockingFailureException
do {
numAttempts++
try {
return pjp.proceed()
} catch (ex: PessimisticLockingFailureException) {
lockFailureException = ex
}
} while (numAttempts <= this.maxRetries)
throw lockFailureException
}
}
----
======
Note that the aspect implements the `Ordered` interface so that we can set the precedence of
the aspect higher than the transaction advice (we want a fresh transaction each time we
retry). The `maxRetries` and `order` properties are both configured by Spring. The
main action happens in the `doConcurrentOperation` around advice method. We try to
proceed. If we fail with a `PessimisticLockingFailureException`, we try again,
unless we have exhausted all of our retry attempts.
NOTE: This class is identical to the one used in the @AspectJ example, but with the
annotations removed.
The corresponding Spring configuration is as follows:
[source,xml,indent=0,subs="verbatim"]
----
<aop:config>
<aop:aspect id="concurrentOperationRetry" ref="concurrentOperationExecutor">
<aop:pointcut id="idempotentOperation"
expression="execution(* com.xyz.service.*.*(..))"/>
<aop:around
pointcut-ref="idempotentOperation"
method="doConcurrentOperation"/>
</aop:aspect>
</aop:config>
<bean id="concurrentOperationExecutor"
class="com.xyz.service.impl.ConcurrentOperationExecutor">
<property name="maxRetries" value="3"/>
<property name="order" value="100"/>
</bean>
----
Notice that, for the time being, we assume that all business services are idempotent. If
this is not the case, we can refine the aspect so that it retries only genuinely
idempotent operations, by introducing an `Idempotent` annotation and using the annotation
to annotate the implementation of service operations, as the following example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
@Retention(RetentionPolicy.RUNTIME)
// marker annotation
public @interface Idempotent {
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
@Retention(AnnotationRetention.RUNTIME)
// marker annotation
annotation class Idempotent
----
======
The
change to the aspect to retry only idempotent operations involves refining the
pointcut expression so that only `@Idempotent` operations match, as follows:
[source,xml,indent=0,subs="verbatim"]
----
<aop:pointcut id="idempotentOperation"
expression="execution(* com.xyz.service.*.*(..)) and
@annotation(com.xyz.service.Idempotent)"/>
----
@@ -1,987 +0,0 @@
[[aop-using-aspectj]]
= Using AspectJ with Spring Applications
Everything we have covered so far in this chapter is pure Spring AOP. In this section,
we look at how you can use the AspectJ compiler or weaver instead of or in
addition to Spring AOP if your needs go beyond the facilities offered by Spring AOP
alone.
Spring ships with a small AspectJ aspect library, which is available stand-alone in your
distribution as `spring-aspects.jar`. You need to add this to your classpath in order
to use the aspects in it. xref:core/aop/using-aspectj.adoc#aop-atconfigurable[Using AspectJ to Dependency Inject Domain Objects with Spring] and xref:core/aop/using-aspectj.adoc#aop-ajlib-other[Other Spring aspects for AspectJ] discuss the
content of this library and how you can use it. xref:core/aop/using-aspectj.adoc#aop-aj-configure[Configuring AspectJ Aspects by Using Spring IoC] discusses how to
dependency inject AspectJ aspects that are woven using the AspectJ compiler. Finally,
xref:core/aop/using-aspectj.adoc#aop-aj-ltw[Load-time Weaving with AspectJ in the Spring Framework] provides an introduction to load-time weaving for Spring applications
that use AspectJ.
[[aop-atconfigurable]]
== Using AspectJ to Dependency Inject Domain Objects with Spring
The Spring container instantiates and configures beans defined in your application
context. It is also possible to ask a bean factory to configure a pre-existing
object, given the name of a bean definition that contains the configuration to be applied.
`spring-aspects.jar` contains an annotation-driven aspect that exploits this
capability to allow dependency injection of any object. The support is intended to
be used for objects created outside of the control of any container. Domain objects
often fall into this category because they are often created programmatically with the
`new` operator or by an ORM tool as a result of a database query.
The `@Configurable` annotation marks a class as being eligible for Spring-driven
configuration. In the simplest case, you can use purely it as a marker annotation, as the
following example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary",chomp="-packages"]
----
package com.xyz.domain;
import org.springframework.beans.factory.annotation.Configurable;
@Configurable
public class Account {
// ...
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary",chomp="-packages"]
----
package com.xyz.domain
import org.springframework.beans.factory.annotation.Configurable
@Configurable
class Account {
// ...
}
----
======
When used as a marker interface in this way, Spring configures new instances of the
annotated type (`Account`, in this case) by using a bean definition (typically
prototype-scoped) with the same name as the fully-qualified type name
(`com.xyz.domain.Account`). Since the default name for a bean is the
fully-qualified name of its type, a convenient way to declare the prototype definition
is to omit the `id` attribute, as the following example shows:
[source,xml,indent=0,subs="verbatim"]
----
<bean class="com.xyz.domain.Account" scope="prototype">
<property name="fundsTransferService" ref="fundsTransferService"/>
</bean>
----
If you want to explicitly specify the name of the prototype bean definition to use, you
can do so directly in the annotation, as the following example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary",chomp="-packages"]
----
package com.xyz.domain;
import org.springframework.beans.factory.annotation.Configurable;
@Configurable("account")
public class Account {
// ...
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary",chomp="-packages"]
----
package com.xyz.domain
import org.springframework.beans.factory.annotation.Configurable
@Configurable("account")
class Account {
// ...
}
----
======
Spring now looks for a bean definition named `account` and uses that as the
definition to configure new `Account` instances.
You can also use autowiring to avoid having to specify a dedicated bean definition at
all. To have Spring apply autowiring, use the `autowire` property of the `@Configurable`
annotation. You can specify either `@Configurable(autowire=Autowire.BY_TYPE)` or
`@Configurable(autowire=Autowire.BY_NAME)` for autowiring by type or by name,
respectively. As an alternative, it is preferable to specify explicit, annotation-driven
dependency injection for your `@Configurable` beans through `@Autowired` or `@Inject`
at the field or method level (see xref:core/beans/annotation-config.adoc[Annotation-based Container Configuration] for further details).
Finally, you can enable Spring dependency checking for the object references in the newly
created and configured object by using the `dependencyCheck` attribute (for example,
`@Configurable(autowire=Autowire.BY_NAME,dependencyCheck=true)`). If this attribute is
set to `true`, Spring validates after configuration that all properties (which
are not primitives or collections) have been set.
Note that using the annotation on its own does nothing. It is the
`AnnotationBeanConfigurerAspect` in `spring-aspects.jar` that acts on the presence of
the annotation. In essence, the aspect says, "after returning from the initialization of
a new object of a type annotated with `@Configurable`, configure the newly created object
using Spring in accordance with the properties of the annotation". In this context,
"initialization" refers to newly instantiated objects (for example, objects instantiated
with the `new` operator) as well as to `Serializable` objects that are undergoing
deserialization (for example, through
{java-api}/java.base/java/io/Serializable.html[readResolve()]).
[NOTE]
=====
One of the key phrases in the above paragraph is "in essence". For most cases, the
exact semantics of "after returning from the initialization of a new object" are
fine. In this context, "after initialization" means that the dependencies are
injected after the object has been constructed. This means that the dependencies
are not available for use in the constructor bodies of the class. If you want the
dependencies to be injected before the constructor bodies run and thus be
available for use in the body of the constructors, you need to define this on the
`@Configurable` declaration, as follows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
@Configurable(preConstruction = true)
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
@Configurable(preConstruction = true)
----
======
You can find more information about the language semantics of the various pointcut
types in AspectJ
{aspectj-docs-progguide}/semantics-joinPoints.html[in this appendix] of the
{aspectj-docs-progguide}/index.html[AspectJ Programming Guide].
=====
For this to work, the annotated types must be woven with the AspectJ weaver. You can
either use a build-time Ant or Maven task to do this (see, for example, the
{aspectj-docs-devguide}/antTasks.html[AspectJ Development
Environment Guide]) or load-time weaving (see xref:core/aop/using-aspectj.adoc#aop-aj-ltw[Load-time Weaving with AspectJ in the Spring Framework]). The
`AnnotationBeanConfigurerAspect` itself needs to be configured by Spring (in order to obtain
a reference to the bean factory that is to be used to configure new objects). If you
use Java-based configuration, you can add `@EnableSpringConfigured` to any
`@Configuration` class, as follows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
@Configuration
@EnableSpringConfigured
public class AppConfig {
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
@Configuration
@EnableSpringConfigured
class AppConfig {
}
----
======
If you prefer XML based configuration, the Spring
xref:core/appendix/xsd-schemas.adoc#context[`context` namespace]
defines a convenient `context:spring-configured` element, which you can use as follows:
[source,xml,indent=0,subs="verbatim"]
----
<context:spring-configured/>
----
Instances of `@Configurable` objects created before the aspect has been configured
result in a message being issued to the debug log and no configuration of the
object taking place. An example might be a bean in the Spring configuration that creates
domain objects when it is initialized by Spring. In this case, you can use the
`depends-on` bean attribute to manually specify that the bean depends on the
configuration aspect. The following example shows how to use the `depends-on` attribute:
[source,xml,indent=0,subs="verbatim"]
----
<bean id="myService"
class="com.xyz.service.MyService"
depends-on="org.springframework.beans.factory.aspectj.AnnotationBeanConfigurerAspect">
<!-- ... -->
</bean>
----
NOTE: Do not activate `@Configurable` processing through the bean configurer aspect unless you
really mean to rely on its semantics at runtime. In particular, make sure that you do
not use `@Configurable` on bean classes that are registered as regular Spring beans
with the container. Doing so results in double initialization, once through the
container and once through the aspect.
[[aop-configurable-testing]]
=== Unit Testing `@Configurable` Objects
One of the goals of the `@Configurable` support is to enable independent unit testing
of domain objects without the difficulties associated with hard-coded lookups.
If `@Configurable` types have not been woven by AspectJ, the annotation has no affect
during unit testing. You can set mock or stub property references in the object under
test and proceed as normal. If `@Configurable` types have been woven by AspectJ,
you can still unit test outside of the container as normal, but you see a warning
message each time that you construct a `@Configurable` object indicating that it has
not been configured by Spring.
[[aop-configurable-container]]
=== Working with Multiple Application Contexts
The `AnnotationBeanConfigurerAspect` that is used to implement the `@Configurable` support
is an AspectJ singleton aspect. The scope of a singleton aspect is the same as the scope
of `static` members: There is one aspect instance per `ClassLoader` that defines the type.
This means that, if you define multiple application contexts within the same `ClassLoader`
hierarchy, you need to consider where to define the `@EnableSpringConfigured` bean and
where to place `spring-aspects.jar` on the classpath.
Consider a typical Spring web application configuration that has a shared parent application
context that defines common business services, everything needed to support those services,
and one child application context for each servlet (which contains definitions particular
to that servlet). All of these contexts co-exist within the same `ClassLoader` hierarchy,
and so the `AnnotationBeanConfigurerAspect` can hold a reference to only one of them.
In this case, we recommend defining the `@EnableSpringConfigured` bean in the shared
(parent) application context. This defines the services that you are likely to want to
inject into domain objects. A consequence is that you cannot configure domain objects
with references to beans defined in the child (servlet-specific) contexts by using the
@Configurable mechanism (which is probably not something you want to do anyway).
When deploying multiple web applications within the same container, ensure that each
web application loads the types in `spring-aspects.jar` by using its own `ClassLoader`
(for example, by placing `spring-aspects.jar` in `WEB-INF/lib`). If `spring-aspects.jar`
is added only to the container-wide classpath (and hence loaded by the shared parent
`ClassLoader`), all web applications share the same aspect instance (which is probably
not what you want).
[[aop-ajlib-other]]
== Other Spring aspects for AspectJ
In addition to the `@Configurable` aspect, `spring-aspects.jar` contains an AspectJ
aspect that you can use to drive Spring's transaction management for types and methods
annotated with the `@Transactional` annotation. This is primarily intended for users who
want to use the Spring Framework's transaction support outside of the Spring container.
The aspect that interprets `@Transactional` annotations is the
`AnnotationTransactionAspect`. When you use this aspect, you must annotate the
implementation class (or methods within that class or both), not the interface (if
any) that the class implements. AspectJ follows Java's rule that annotations on
interfaces are not inherited.
A `@Transactional` annotation on a class specifies the default transaction semantics for
the execution of any public operation in the class.
A `@Transactional` annotation on a method within the class overrides the default
transaction semantics given by the class annotation (if present). Methods of any
visibility may be annotated, including private methods. Annotating non-public methods
directly is the only way to get transaction demarcation for the execution of such methods.
TIP: Since Spring Framework 4.2, `spring-aspects` provides a similar aspect that offers the
exact same features for the standard `jakarta.transaction.Transactional` annotation. Check
`JtaAnnotationTransactionAspect` for more details.
For AspectJ programmers who want to use the Spring configuration and transaction
management support but do not want to (or cannot) use annotations, `spring-aspects.jar`
also contains `abstract` aspects you can extend to provide your own pointcut
definitions. See the sources for the `AbstractBeanConfigurerAspect` and
`AbstractTransactionAspect` aspects for more information. As an example, the following
excerpt shows how you could write an aspect to configure all instances of objects
defined in the domain model by using prototype bean definitions that match the
fully qualified class names:
[source,java,indent=0,subs="verbatim"]
----
public aspect DomainObjectConfiguration extends AbstractBeanConfigurerAspect {
public DomainObjectConfiguration() {
setBeanWiringInfoResolver(new ClassNameBeanWiringInfoResolver());
}
// the creation of a new bean (any object in the domain model)
protected pointcut beanCreation(Object beanInstance) :
initialization(new(..)) &&
CommonPointcuts.inDomainModel() &&
this(beanInstance);
}
----
[[aop-aj-configure]]
== Configuring AspectJ Aspects by Using Spring IoC
When you use AspectJ aspects with Spring applications, it is natural to both want and
expect to be able to configure such aspects with Spring. The AspectJ runtime itself is
responsible for aspect creation, and the means of configuring the AspectJ-created
aspects through Spring depends on the AspectJ instantiation model (the `per-xxx` clause)
used by the aspect.
The majority of AspectJ aspects are singleton aspects. Configuration of these
aspects is easy. You can create a bean definition that references the aspect type as
normal and include the `factory-method="aspectOf"` bean attribute. This ensures that
Spring obtains the aspect instance by asking AspectJ for it rather than trying to create
an instance itself. The following example shows how to use the `factory-method="aspectOf"` attribute:
[source,xml,indent=0,subs="verbatim"]
----
<bean id="profiler" class="com.xyz.profiler.Profiler"
factory-method="aspectOf"> <1>
<property name="profilingStrategy" ref="jamonProfilingStrategy"/>
</bean>
----
<1> Note the `factory-method="aspectOf"` attribute
Non-singleton aspects are harder to configure. However, it is possible to do so by
creating prototype bean definitions and using the `@Configurable` support from
`spring-aspects.jar` to configure the aspect instances once they have bean created by
the AspectJ runtime.
If you have some @AspectJ aspects that you want to weave with AspectJ (for example,
using load-time weaving for domain model types) and other @AspectJ aspects that you want
to use with Spring AOP, and these aspects are all configured in Spring, you
need to tell the Spring AOP @AspectJ auto-proxying support which exact subset of the
@AspectJ aspects defined in the configuration should be used for auto-proxying. You can
do this by using one or more `<include/>` elements inside the `<aop:aspectj-autoproxy/>`
declaration. Each `<include/>` element specifies a name pattern, and only beans with
names matched by at least one of the patterns are used for Spring AOP auto-proxy
configuration. The following example shows how to use `<include/>` elements:
[source,xml,indent=0,subs="verbatim"]
----
<aop:aspectj-autoproxy>
<aop:include name="thisBean"/>
<aop:include name="thatBean"/>
</aop:aspectj-autoproxy>
----
NOTE: Do not be misled by the name of the `<aop:aspectj-autoproxy/>` element. Using it
results in the creation of Spring AOP proxies. The @AspectJ style of aspect
declaration is being used here, but the AspectJ runtime is not involved.
[[aop-aj-ltw]]
== Load-time Weaving with AspectJ in the Spring Framework
Load-time weaving (LTW) refers to the process of weaving AspectJ aspects into an
application's class files as they are being loaded into the Java virtual machine (JVM).
The focus of this section is on configuring and using LTW in the specific context of the
Spring Framework. This section is not a general introduction to LTW. For full details on
the specifics of LTW and configuring LTW with only AspectJ (with Spring not being
involved at all), see the
{aspectj-docs-devguide}/ltw.html[LTW section of the AspectJ
Development Environment Guide].
The value that the Spring Framework brings to AspectJ LTW is in enabling much
finer-grained control over the weaving process. 'Vanilla' AspectJ LTW is effected by using
a Java (5+) agent, which is switched on by specifying a VM argument when starting up a
JVM. It is, thus, a JVM-wide setting, which may be fine in some situations but is often a
little too coarse. Spring-enabled LTW lets you switch on LTW on a
per-`ClassLoader` basis, which is more fine-grained and which can make more
sense in a 'single-JVM-multiple-application' environment (such as is found in a typical
application server environment).
Further, xref:core/aop/using-aspectj.adoc#aop-aj-ltw-environments[in certain environments], this support enables
load-time weaving without making any modifications to the application server's launch
script that is needed to add `-javaagent:path/to/aspectjweaver.jar` or (as we describe
later in this section) `-javaagent:path/to/spring-instrument.jar`. Developers configure
the application context to enable load-time weaving instead of relying on administrators
who typically are in charge of the deployment configuration, such as the launch script.
Now that the sales pitch is over, let us first walk through a quick example of AspectJ
LTW that uses Spring, followed by detailed specifics about elements introduced in the
example. For a complete example, see the
{spring-github-org}/spring-petclinic[Petclinic sample application].
[[aop-aj-ltw-first-example]]
=== A First Example
Assume that you are an application developer who has been tasked with diagnosing
the cause of some performance problems in a system. Rather than break out a
profiling tool, we are going to switch on a simple profiling aspect that lets us
quickly get some performance metrics. We can then apply a finer-grained profiling
tool to that specific area immediately afterwards.
NOTE: The example presented here uses XML configuration. You can also configure and
use @AspectJ with xref:core/beans/java.adoc[Java configuration]. Specifically, you can use the
`@EnableLoadTimeWeaving` annotation as an alternative to `<context:load-time-weaver/>`
(see xref:core/aop/using-aspectj.adoc#aop-aj-ltw-spring[below] for details).
The following example shows the profiling aspect, which is not fancy.
It is a time-based profiler that uses the @AspectJ-style of aspect declaration:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary",chomp="-packages"]
----
package com.xyz;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.util.StopWatch;
import org.springframework.core.annotation.Order;
@Aspect
public class ProfilingAspect {
@Around("methodsToBeProfiled()")
public Object profile(ProceedingJoinPoint pjp) throws Throwable {
StopWatch sw = new StopWatch(getClass().getSimpleName());
try {
sw.start(pjp.getSignature().getName());
return pjp.proceed();
} finally {
sw.stop();
System.out.println(sw.prettyPrint());
}
}
@Pointcut("execution(public * com.xyz..*.*(..))")
public void methodsToBeProfiled(){}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary",chomp="-packages"]
----
package com.xyz
import org.aspectj.lang.ProceedingJoinPoint
import org.aspectj.lang.annotation.Aspect
import org.aspectj.lang.annotation.Around
import org.aspectj.lang.annotation.Pointcut
import org.springframework.util.StopWatch
import org.springframework.core.annotation.Order
@Aspect
class ProfilingAspect {
@Around("methodsToBeProfiled()")
fun profile(pjp: ProceedingJoinPoint): Any? {
val sw = StopWatch(javaClass.simpleName)
try {
sw.start(pjp.getSignature().getName())
return pjp.proceed()
} finally {
sw.stop()
println(sw.prettyPrint())
}
}
@Pointcut("execution(public * com.xyz..*.*(..))")
fun methodsToBeProfiled() {
}
}
----
======
We also need to create an `META-INF/aop.xml` file, to inform the AspectJ weaver that
we want to weave our `ProfilingAspect` into our classes. This file convention, namely
the presence of a file (or files) on the Java classpath called `META-INF/aop.xml` is
standard AspectJ. The following example shows the `aop.xml` file:
[source,xml,indent=0,subs="verbatim"]
----
<!DOCTYPE aspectj PUBLIC "-//AspectJ//DTD//EN" "https://www.eclipse.org/aspectj/dtd/aspectj.dtd">
<aspectj>
<weaver>
<!-- only weave classes in our application-specific packages -->
<include within="com.xyz.*"/>
</weaver>
<aspects>
<!-- weave in just this aspect -->
<aspect name="com.xyz.ProfilingAspect"/>
</aspects>
</aspectj>
----
Now we can move on to the Spring-specific portion of the configuration. We need
to configure a `LoadTimeWeaver` (explained later). This load-time weaver is the
essential component responsible for weaving the aspect configuration in one or
more `META-INF/aop.xml` files into the classes in your application. The good
thing is that it does not require a lot of configuration (there are some more
options that you can specify, but these are detailed later), as can be seen in
the following example:
[source,xml,indent=0,subs="verbatim"]
----
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
https://www.springframework.org/schema/context/spring-context.xsd">
<!-- a service object; we will be profiling its methods -->
<bean id="entitlementCalculationService"
class="com.xyz.StubEntitlementCalculationService"/>
<!-- this switches on the load-time weaving -->
<context:load-time-weaver/>
</beans>
----
Now that all the required artifacts (the aspect, the `META-INF/aop.xml`
file, and the Spring configuration) are in place, we can create the following
driver class with a `main(..)` method to demonstrate the LTW in action:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary",chomp="-packages"]
----
package com.xyz;
// imports
public class Main {
public static void main(String[] args) {
ApplicationContext ctx = new ClassPathXmlApplicationContext("beans.xml");
EntitlementCalculationService service =
ctx.getBean(EntitlementCalculationService.class);
// the profiling aspect is 'woven' around this method execution
service.calculateEntitlement();
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary",chomp="-packages"]
----
package com.xyz
// imports
fun main() {
val ctx = ClassPathXmlApplicationContext("beans.xml")
val service = ctx.getBean(EntitlementCalculationService.class)
// the profiling aspect is 'woven' around this method execution
service.calculateEntitlement()
}
----
======
We have one last thing to do. The introduction to this section did say that one could
switch on LTW selectively on a per-`ClassLoader` basis with Spring, and this is true.
However, for this example, we use a Java agent (supplied with Spring) to switch on LTW.
We use the following command to run the `Main` class shown earlier:
[literal,subs="verbatim"]
----
java -javaagent:C:/projects/xyz/lib/spring-instrument.jar com.xyz.Main
----
The `-javaagent` is a flag for specifying and enabling
{java-api}/java.instrument/java/lang/instrument/package-summary.html[agents
to instrument programs that run on the JVM]. The Spring Framework ships with such an
agent, the `InstrumentationSavingAgent`, which is packaged in the
`spring-instrument.jar` that was supplied as the value of the `-javaagent` argument in
the preceding example.
The output from the execution of the `Main` program looks something like the next example.
(I have introduced a `Thread.sleep(..)` statement into the `calculateEntitlement()`
implementation so that the profiler actually captures something other than 0
milliseconds (the `01234` milliseconds is not an overhead introduced by the AOP).
The following listing shows the output we got when we ran our profiler:
[literal,subs="verbatim"]
----
Calculating entitlement
StopWatch 'ProfilingAspect': running time (millis) = 1234
------ ----- ----------------------------
ms % Task name
------ ----- ----------------------------
01234 100% calculateEntitlement
----
Since this LTW is effected by using full-blown AspectJ, we are not limited only to advising
Spring beans. The following slight variation on the `Main` program yields the same
result:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary",chomp="-packages"]
----
package com.xyz;
// imports
public class Main {
public static void main(String[] args) {
new ClassPathXmlApplicationContext("beans.xml");
EntitlementCalculationService service =
new StubEntitlementCalculationService();
// the profiling aspect will be 'woven' around this method execution
service.calculateEntitlement();
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary",chomp="-packages"]
----
package com.xyz
// imports
fun main(args: Array<String>) {
ClassPathXmlApplicationContext("beans.xml")
val service = StubEntitlementCalculationService()
// the profiling aspect will be 'woven' around this method execution
service.calculateEntitlement()
}
----
======
Notice how, in the preceding program, we bootstrap the Spring container and
then create a new instance of the `StubEntitlementCalculationService` totally outside
the context of Spring. The profiling advice still gets woven in.
Admittedly, the example is simplistic. However, the basics of the LTW support in Spring
have all been introduced in the earlier example, and the rest of this section explains
the "why" behind each bit of configuration and usage in detail.
NOTE: The `ProfilingAspect` used in this example may be basic, but it is quite useful. It is a
nice example of a development-time aspect that developers can use during development
and then easily exclude from builds of the application being deployed
into UAT or production.
[[aop-aj-ltw-the-aspects]]
=== Aspects
The aspects that you use in LTW have to be AspectJ aspects. You can write them in
either the AspectJ language itself, or you can write your aspects in the @AspectJ-style.
Your aspects are then both valid AspectJ and Spring AOP aspects.
Furthermore, the compiled aspect classes need to be available on the classpath.
[[aop-aj-ltw-aop_dot_xml]]
=== 'META-INF/aop.xml'
The AspectJ LTW infrastructure is configured by using one or more `META-INF/aop.xml`
files that are on the Java classpath (either directly or, more typically, in jar files).
The structure and contents of this file is detailed in the LTW part of the
{aspectj-docs-devguide}/ltw-configuration.html[AspectJ reference
documentation]. Because the `aop.xml` file is 100% AspectJ, we do not describe it further here.
[[aop-aj-ltw-libraries]]
=== Required libraries (JARS)
At minimum, you need the following libraries to use the Spring Framework's support
for AspectJ LTW:
* `spring-aop.jar`
* `aspectjweaver.jar`
If you use the xref:core/aop/using-aspectj.adoc#aop-aj-ltw-environments-generic[Spring-provided agent to enable instrumentation]
, you also need:
* `spring-instrument.jar`
[[aop-aj-ltw-spring]]
=== Spring Configuration
The key component in Spring's LTW support is the `LoadTimeWeaver` interface (in the
`org.springframework.instrument.classloading` package), and the numerous implementations
of it that ship with the Spring distribution. A `LoadTimeWeaver` is responsible for
adding one or more `java.lang.instrument.ClassFileTransformers` to a `ClassLoader` at
runtime, which opens the door to all manner of interesting applications, one of which
happens to be the LTW of aspects.
TIP: If you are unfamiliar with the idea of runtime class file transformation, see the
javadoc API documentation for the `java.lang.instrument` package before continuing.
While that documentation is not comprehensive, at least you can see the key interfaces
and classes (for reference as you read through this section).
Configuring a `LoadTimeWeaver` for a particular `ApplicationContext` can be as easy as
adding one line. (Note that you almost certainly need to use an
`ApplicationContext` as your Spring container -- typically, a `BeanFactory` is not
enough because the LTW support uses `BeanFactoryPostProcessors`.)
To enable the Spring Framework's LTW support, you need to configure a `LoadTimeWeaver`,
which typically is done by using the `@EnableLoadTimeWeaving` annotation, as follows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
@Configuration
@EnableLoadTimeWeaving
public class AppConfig {
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
@Configuration
@EnableLoadTimeWeaving
class AppConfig {
}
----
======
Alternatively, if you prefer XML-based configuration, use the
`<context:load-time-weaver/>` element. Note that the element is defined in the
`context` namespace. The following example shows how to use `<context:load-time-weaver/>`:
[source,xml,indent=0,subs="verbatim"]
----
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
https://www.springframework.org/schema/context/spring-context.xsd">
<context:load-time-weaver/>
</beans>
----
The preceding configuration automatically defines and registers a number of LTW-specific
infrastructure beans, such as a `LoadTimeWeaver` and an `AspectJWeavingEnabler`, for you.
The default `LoadTimeWeaver` is the `DefaultContextLoadTimeWeaver` class, which attempts
to decorate an automatically detected `LoadTimeWeaver`. The exact type of `LoadTimeWeaver`
that is "automatically detected" is dependent upon your runtime environment.
The following table summarizes various `LoadTimeWeaver` implementations:
[[aop-aj-ltw-spring-env-impls]]
.DefaultContextLoadTimeWeaver LoadTimeWeavers
|===
| Runtime Environment| `LoadTimeWeaver` implementation
| Running in https://tomcat.apache.org/[Apache Tomcat]
| `TomcatLoadTimeWeaver`
| Running in https://eclipse-ee4j.github.io/glassfish/[GlassFish] (limited to EAR deployments)
| `GlassFishLoadTimeWeaver`
| Running in Red Hat's https://www.jboss.org/jbossas/[JBoss AS] or https://www.wildfly.org/[WildFly]
| `JBossLoadTimeWeaver`
| JVM started with Spring `InstrumentationSavingAgent`
(`java -javaagent:path/to/spring-instrument.jar`)
| `InstrumentationLoadTimeWeaver`
| Fallback, expecting the underlying ClassLoader to follow common conventions
(namely `addTransformer` and optionally a `getThrowawayClassLoader` method)
| `ReflectiveLoadTimeWeaver`
|===
Note that the table lists only the `LoadTimeWeavers` that are autodetected when you
use the `DefaultContextLoadTimeWeaver`. You can specify exactly which `LoadTimeWeaver`
implementation to use.
To specify a specific `LoadTimeWeaver` with Java configuration, implement the
`LoadTimeWeavingConfigurer` interface and override the `getLoadTimeWeaver()` method.
The following example specifies a `ReflectiveLoadTimeWeaver`:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim",role="primary"]
----
@Configuration
@EnableLoadTimeWeaving
public class AppConfig implements LoadTimeWeavingConfigurer {
@Override
public LoadTimeWeaver getLoadTimeWeaver() {
return new ReflectiveLoadTimeWeaver();
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim",role="secondary"]
----
@Configuration
@EnableLoadTimeWeaving
class AppConfig : LoadTimeWeavingConfigurer {
override fun getLoadTimeWeaver(): LoadTimeWeaver {
return ReflectiveLoadTimeWeaver()
}
}
----
======
If you use XML-based configuration, you can specify the fully qualified class name
as the value of the `weaver-class` attribute on the `<context:load-time-weaver/>`
element. Again, the following example specifies a `ReflectiveLoadTimeWeaver`:
[source,xml,indent=0,subs="verbatim"]
----
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
https://www.springframework.org/schema/context/spring-context.xsd">
<context:load-time-weaver
weaver-class="org.springframework.instrument.classloading.ReflectiveLoadTimeWeaver"/>
</beans>
----
The `LoadTimeWeaver` that is defined and registered by the configuration can be later
retrieved from the Spring container by using the well known name, `loadTimeWeaver`.
Remember that the `LoadTimeWeaver` exists only as a mechanism for Spring's LTW
infrastructure to add one or more `ClassFileTransformers`. The actual
`ClassFileTransformer` that does the LTW is the `ClassPreProcessorAgentAdapter` (from
the `org.aspectj.weaver.loadtime` package) class. See the class-level javadoc of the
`ClassPreProcessorAgentAdapter` class for further details, because the specifics of how
the weaving is actually effected is beyond the scope of this document.
There is one final attribute of the configuration left to discuss: the `aspectjWeaving`
attribute (or `aspectj-weaving` if you use XML). This attribute controls whether LTW
is enabled or not. It accepts one of three possible values, with the default value being
`autodetect` if the attribute is not present. The following table summarizes the three
possible values:
[[aop-aj-ltw-ltw-tag-attrs]]
.AspectJ weaving attribute values
|===
| Annotation Value| XML Value| Explanation
| `ENABLED`
| `on`
| AspectJ weaving is on, and aspects are woven at load-time as appropriate.
| `DISABLED`
| `off`
| LTW is off. No aspect is woven at load-time.
| `AUTODETECT`
| `autodetect`
| If the Spring LTW infrastructure can find at least one `META-INF/aop.xml` file,
then AspectJ weaving is on. Otherwise, it is off. This is the default value.
|===
[[aop-aj-ltw-environments]]
=== Environment-specific Configuration
This last section contains any additional settings and configuration that you need
when you use Spring's LTW support in environments such as application servers and web
containers.
[[aop-aj-ltw-environments-tomcat-jboss-etc]]
==== Tomcat, JBoss, WildFly
Tomcat and JBoss/WildFly provide a general app `ClassLoader` that is capable of local
instrumentation. Spring's native LTW may leverage those ClassLoader implementations
to provide AspectJ weaving.
You can simply enable load-time weaving, as xref:core/aop/using-aspectj.adoc[described earlier].
Specifically, you do not need to modify the JVM launch script to add
`-javaagent:path/to/spring-instrument.jar`.
Note that on JBoss, you may need to disable the app server scanning to prevent it from
loading the classes before the application actually starts. A quick workaround is to add
to your artifact a file named `WEB-INF/jboss-scanning.xml` with the following content:
[source,xml,indent=0,subs="verbatim"]
----
<scanning xmlns="urn:jboss:scanning:1.0"/>
----
[[aop-aj-ltw-environments-generic]]
==== Generic Java Applications
When class instrumentation is required in environments that are not supported by
specific `LoadTimeWeaver` implementations, a JVM agent is the general solution.
For such cases, Spring provides `InstrumentationLoadTimeWeaver` which requires a
Spring-specific (but very general) JVM agent, `spring-instrument.jar`, autodetected
by common `@EnableLoadTimeWeaving` and `<context:load-time-weaver/>` setups.
To use it, you must start the virtual machine with the Spring agent by supplying
the following JVM options:
[literal]
[subs="verbatim"]
----
-javaagent:/path/to/spring-instrument.jar
----
Note that this requires modification of the JVM launch script, which may prevent you
from using this in application server environments (depending on your server and your
operation policies). That said, for one-app-per-JVM deployments such as standalone
Spring Boot applications, you typically control the entire JVM setup in any case.
@@ -1,506 +0,0 @@
[[aot]]
= Ahead of Time Optimizations
This chapter covers Spring's Ahead of Time (AOT) optimizations.
For AOT support specific to integration tests, see xref:testing/testcontext-framework/aot.adoc[Ahead of Time Support for Tests].
[[aot.introduction]]
== Introduction to Ahead of Time Optimizations
Spring's support for AOT optimizations is meant to inspect an `ApplicationContext` at build time and apply decisions and discovery logic that usually happens at runtime.
Doing so allows building an application startup arrangement that is more straightforward and focused on a fixed set of features based mainly on the classpath and the `Environment`.
Applying such optimizations early implies the following restrictions:
* The classpath is fixed and fully defined at build time.
* The beans defined in your application cannot change at runtime, meaning:
** `@Profile`, in particular profile-specific configuration needs to be chosen at build time.
** `Environment` properties that impact the presence of a bean (`@Conditional`) are only considered at build time.
* Bean definitions with instance suppliers (lambdas or method references) cannot be transformed ahead-of-time (see related {spring-framework-issues}/29555[spring-framework#29555] issue).
* Make sure that the bean type is as precise as possible.
TIP: See also the xref:core/aot.adoc#aot.bestpractices[] section.
When these restrictions are in place, it becomes possible to perform ahead-of-time processing at build time and generate additional assets.
A Spring AOT processed application typically generates:
* Java source code
* Bytecode (usually for dynamic proxies)
* {spring-framework-api}/aot/hint/RuntimeHints.html[`RuntimeHints`] for the use of reflection, resource loading, serialization, and JDK proxies.
NOTE: At the moment, AOT is focused on allowing Spring applications to be deployed as native images using GraalVM.
We intend to support more JVM-based use cases in future generations.
[[aot.basics]]
== AOT engine overview
The entry point of the AOT engine for processing an `ApplicationContext` arrangement is `ApplicationContextAotGenerator`. It takes care of the following steps, based on a `GenericApplicationContext` that represents the application to optimize and a {spring-framework-api}/aot/generate/GenerationContext.html[`GenerationContext`]:
* Refresh an `ApplicationContext` for AOT processing. Contrary to a traditional refresh, this version only creates bean definitions, not bean instances.
* Invoke the available `BeanFactoryInitializationAotProcessor` implementations and apply their contributions against the `GenerationContext`.
For instance, a core implementation iterates over all candidate bean definitions and generates the necessary code to restore the state of the `BeanFactory`.
Once this process completes, the `GenerationContext` will have been updated with the generated code, resources, and classes that are necessary for the application to run.
The `RuntimeHints` instance can also be used to generate the relevant GraalVM native image configuration files.
`ApplicationContextAotGenerator#processAheadOfTime` returns the class name of the `ApplicationContextInitializer` entry point that allows the context to be started with AOT optimizations.
Those steps are covered in greater detail in the sections below.
[[aot.refresh]]
== Refresh for AOT Processing
Refresh for AOT processing is supported on all `GenericApplicationContext` implementations.
An application context is created with any number of entry points, usually in the form of `@Configuration`-annotated classes.
Let's look at a basic example:
include-code::./AotProcessingSample[tag=myapplication]
Starting this application with the regular runtime involves a number of steps including classpath scanning, configuration class parsing, bean instantiation, and lifecycle callback handling.
Refresh for AOT processing only applies a subset of what happens with a xref:core/beans/introduction.adoc[regular `refresh`].
AOT processing can be triggered as follows:
include-code::./AotProcessingSample[tag=aotcontext]
In this mode, xref:core/beans/factory-extension.adoc#beans-factory-extension-factory-postprocessors[`BeanFactoryPostProcessor` implementations] are invoked as usual.
This includes configuration class parsing, import selectors, classpath scanning, etc.
Such steps make sure that the `BeanRegistry` contains the relevant bean definitions for the application.
If bean definitions are guarded by conditions (such as `@Profile`), these are discarded at this stage.
Because this mode does not actually create bean instances, `BeanPostProcessor` implementations are not invoked, except for specific variants that are relevant for AOT processing.
These are:
* `MergedBeanDefinitionPostProcessor` implementations post-process bean definitions to extract additional settings, such as `init` and `destroy` methods.
* `SmartInstantiationAwareBeanPostProcessor` implementations determine a more precise bean type if necessary.
This makes sure to create any proxy that will be required at runtime.
Once this part completes, the `BeanFactory` contains the bean definitions that are necessary for the application to run. It does not trigger bean instantiation but allows the AOT engine to inspect the beans that will be created at runtime.
[[aot.bean-factory-initialization-contributions]]
== Bean Factory Initialization AOT Contributions
Components that want to participate in this step can implement the {spring-framework-api}/beans/factory/aot/BeanFactoryInitializationAotProcessor.html[`BeanFactoryInitializationAotProcessor`] interface.
Each implementation can return an AOT contribution, based on the state of the bean factory.
An AOT contribution is a component that contributes generated code that reproduces a particular behavior.
It can also contribute `RuntimeHints` to indicate the need for reflection, resource loading, serialization, or JDK proxies.
A `BeanFactoryInitializationAotProcessor` implementation can be registered in `META-INF/spring/aot.factories` with a key equal to the fully qualified name of the interface.
A `BeanFactoryInitializationAotProcessor` can also be implemented directly by a bean.
In this mode, the bean provides an AOT contribution equivalent to the feature it provides with a regular runtime.
Consequently, such a bean is automatically excluded from the AOT-optimized context.
[NOTE]
====
If a bean implements the `BeanFactoryInitializationAotProcessor` interface, the bean and **all** of its dependencies will be initialized during AOT processing.
We generally recommend that this interface is only implemented by infrastructure beans such as `BeanFactoryPostProcessor` which have limited dependencies and are already initialized early in the bean factory lifecycle.
If such a bean is registered using an `@Bean` factory method, ensure the method is `static` so that its enclosing `@Configuration` class does not have to be initialized.
====
[[aot.bean-registration-contributions]]
=== Bean Registration AOT Contributions
A core `BeanFactoryInitializationAotProcessor` implementation is responsible for collecting the necessary contributions for each candidate `BeanDefinition`.
It does so using a dedicated `BeanRegistrationAotProcessor`.
This interface is used as follows:
* Implemented by a `BeanPostProcessor` bean, to replace its runtime behavior.
For instance xref:core/beans/factory-extension.adoc#beans-factory-extension-bpp-examples-aabpp[`AutowiredAnnotationBeanPostProcessor`] implements this interface to generate code that injects members annotated with `@Autowired`.
* Implemented by a type registered in `META-INF/spring/aot.factories` with a key equal to the fully qualified name of the interface.
Typically used when the bean definition needs to be tuned for specific features of the core framework.
[NOTE]
====
If a bean implements the `BeanRegistrationAotProcessor` interface, the bean and **all** of its dependencies will be initialized during AOT processing.
We generally recommend that this interface is only implemented by infrastructure beans such as `BeanFactoryPostProcessor` which have limited dependencies and are already initialized early in the bean factory lifecycle.
If such a bean is registered using an `@Bean` factory method, ensure the method is `static` so that its enclosing `@Configuration` class does not have to be initialized.
====
If no `BeanRegistrationAotProcessor` handles a particular registered bean, a default implementation processes it.
This is the default behavior, since tuning the generated code for a bean definition should be restricted to corner cases.
Taking our previous example, let's assume that `DataSourceConfiguration` is as follows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
@Configuration(proxyBeanMethods = false)
public class DataSourceConfiguration {
@Bean
public SimpleDataSource dataSource() {
return new SimpleDataSource();
}
}
----
======
Since there isn't any particular condition on this class, `dataSourceConfiguration` and `dataSource` are identified as candidates.
The AOT engine will convert the configuration class above to code similar to the following:
[tabs]
======
Java::
+
[source,java,indent=0,role="primary"]
----
/**
* Bean definitions for {@link DataSourceConfiguration}
*/
@Generated
public class DataSourceConfiguration__BeanDefinitions {
/**
* Get the bean definition for 'dataSourceConfiguration'
*/
public static BeanDefinition getDataSourceConfigurationBeanDefinition() {
Class<?> beanType = DataSourceConfiguration.class;
RootBeanDefinition beanDefinition = new RootBeanDefinition(beanType);
beanDefinition.setInstanceSupplier(DataSourceConfiguration::new);
return beanDefinition;
}
/**
* Get the bean instance supplier for 'dataSource'.
*/
private static BeanInstanceSupplier<SimpleDataSource> getDataSourceInstanceSupplier() {
return BeanInstanceSupplier.<SimpleDataSource>forFactoryMethod(DataSourceConfiguration.class, "dataSource")
.withGenerator((registeredBean) -> registeredBean.getBeanFactory().getBean(DataSourceConfiguration.class).dataSource());
}
/**
* Get the bean definition for 'dataSource'
*/
public static BeanDefinition getDataSourceBeanDefinition() {
Class<?> beanType = SimpleDataSource.class;
RootBeanDefinition beanDefinition = new RootBeanDefinition(beanType);
beanDefinition.setInstanceSupplier(getDataSourceInstanceSupplier());
return beanDefinition;
}
}
----
======
NOTE: The exact code generated may differ depending on the exact nature of your bean definitions.
TIP: Each generated class is annotated with `org.springframework.aot.generate.Generated` to
identify them if they need to be excluded, for instance by static analysis tools.
The generated code above creates bean definitions equivalent to the `@Configuration` class, but in a direct way and without the use of reflection if at all possible.
There is a bean definition for `dataSourceConfiguration` and one for `dataSourceBean`.
When a `datasource` instance is required, a `BeanInstanceSupplier` is called.
This supplier invokes the `dataSource()` method on the `dataSourceConfiguration` bean.
[[aot.bestpractices]]
== Best Practices
The AOT engine is designed to handle as many use cases as possible, with no code change in applications.
However, keep in mind that some optimizations are made at build time based on a static definition of the beans.
This section lists the best practices that make sure your application is ready for AOT.
[[aot.bestpractices.bean-type]]
=== Expose The Most Precise Bean Type
While your application may interact with an interface that a bean implements, it is still very important to declare the most precise type.
The AOT engine performs additional checks on the bean type, such as detecting the presence of `@Autowired` members, or lifecycle callback methods.
For `@Configuration` classes, make sure that the return type of the factory `@Bean` method is as precise as possible.
Consider the following example:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
@Configuration(proxyBeanMethods = false)
public class UserConfiguration {
@Bean
public MyInterface myInterface() {
return new MyImplementation();
}
}
----
======
In the example above, the declared type for the `myInterface` bean is `MyInterface`.
None of the usual post-processing will take `MyImplementation` into account.
For instance, if there is an annotated handler method on `MyImplementation` that the context should register, it wont be detected upfront.
The example above should be rewritten as follows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
@Configuration(proxyBeanMethods = false)
public class UserConfiguration {
@Bean
public MyImplementation myInterface() {
return new MyImplementation();
}
}
----
======
If you are registering bean definitions programmatically, consider using `RootBeanBefinition` as it allows to specify a `ResolvableType` that handles generics.
[[aot.bestpractices.constructors]]
=== Avoid Multiple Constructors
The container is able to choose the most appropriate constructor to use based on several candidates.
However, this is not a best practice and flagging the preferred constructor with `@Autowired` if necessary is preferred.
In case you are working on a code base that you can't modify, you can set the {spring-framework-api}/beans/factory/support/AbstractBeanDefinition.html#PREFERRED_CONSTRUCTORS_ATTRIBUTE[`preferredConstructors` attribute] on the related bean definition to indicate which constructor should be used.
[[aot.bestpractices.factory-bean]]
=== FactoryBean
`FactoryBean` should be used with care as it introduces an intermediate layer in terms of bean type resolution that may not be conceptually necessary.
As a rule of thumb, if the `FactoryBean` instance does not hold long-term state and is not needed at a later point in time at runtime, it should be replaced by a regular factory method, possibly with a `FactoryBean` adapter layer on top (for declarative configuration purposes).
If your `FactoryBean` implementation does not resolve the object type (i.e. `T`), extra care is necessary.
Consider the following example:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class ClientFactoryBean<T extends AbstractClient> implements FactoryBean<T> {
}
----
======
A concrete client declaration should provide a resolved generic for the client, as shown in the following example:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
@Configuration(proxyBeanMethods = false)
public class UserConfiguration {
@Bean
public ClientFactoryBean<MyClient> myClient() {
return new ClientFactoryBean<>(...);
}
}
----
======
If the `FactoryBean` bean definition is registered programmatically, make sure to follow these steps:
1. Use `RootBeanDefinition`.
2. Set the `beanClass` to the `FactoryBean` class so that AOT knows that it is an intermediate layer.
3. Set the `ResolvableType` to a resolved generic, which makes sure the most precise type is exposed.
The following example showcases a basic definition:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
RootBeanDefinition beanDefinition = new RootBeanDefinition(ClientFactoryBean.class);
beanDefinition.setTargetType(ResolvableType.forClassWithGenerics(ClientFactoryBean.class, MyClient.class));
// ...
registry.registerBeanDefinition("myClient", beanDefinition);
----
======
[[aot.bestpractices.jpa]]
=== JPA
The JPA persistence unit has to be known upfront for certain optimizations to apply. Consider the following basic example:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
@Bean
LocalContainerEntityManagerFactoryBean customDBEntityManagerFactory(DataSource dataSource) {
LocalContainerEntityManagerFactoryBean factoryBean = new LocalContainerEntityManagerFactoryBean();
factoryBean.setDataSource(dataSource);
factoryBean.setPackagesToScan("com.example.app");
return factoryBean;
}
----
======
To make sure the scanning occurs ahead of time, a `PersistenceManagedTypes` bean must be declared and used by the
factory bean definition, as shown by the following example:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
@Bean
PersistenceManagedTypes persistenceManagedTypes(ResourceLoader resourceLoader) {
return new PersistenceManagedTypesScanner(resourceLoader)
.scan("com.example.app");
}
@Bean
LocalContainerEntityManagerFactoryBean customDBEntityManagerFactory(DataSource dataSource, PersistenceManagedTypes managedTypes) {
LocalContainerEntityManagerFactoryBean factoryBean = new LocalContainerEntityManagerFactoryBean();
factoryBean.setDataSource(dataSource);
factoryBean.setManagedTypes(managedTypes);
return factoryBean;
}
----
======
[[aot.hints]]
== Runtime Hints
Running an application as a native image requires additional information compared to a regular JVM runtime.
For instance, GraalVM needs to know ahead of time if a component uses reflection.
Similarly, classpath resources are not shipped in a native image unless specified explicitly.
Consequently, if the application needs to load a resource, it must be referenced from the corresponding GraalVM native image configuration file.
The {spring-framework-api}/aot/hint/RuntimeHints.html[`RuntimeHints`] API collects the need for reflection, resource loading, serialization, and JDK proxies at runtime.
The following example makes sure that `config/app.properties` can be loaded from the classpath at runtime within a native image:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
runtimeHints.resources().registerPattern("config/app.properties");
----
======
A number of contracts are handled automatically during AOT processing.
For instance, the return type of a `@Controller` method is inspected, and relevant reflection hints are added if Spring detects that the type should be serialized (typically to JSON).
For cases that the core container cannot infer, you can register such hints programmatically.
A number of convenient annotations are also provided for common use cases.
[[aot.hints.import-runtime-hints]]
=== `@ImportRuntimeHints`
`RuntimeHintsRegistrar` implementations allow you to get a callback to the `RuntimeHints` instance managed by the AOT engine.
Implementations of this interface can be registered using `@ImportRuntimeHints` on any Spring bean or `@Bean` factory method.
`RuntimeHintsRegistrar` implementations are detected and invoked at build time.
include-code::./SpellCheckService[]
If at all possible, `@ImportRuntimeHints` should be used as close as possible to the component that requires the hints.
This way, if the component is not contributed to the `BeanFactory`, the hints won't be contributed either.
It is also possible to register an implementation statically by adding an entry in `META-INF/spring/aot.factories` with a key equal to the fully qualified name of the `RuntimeHintsRegistrar` interface.
[[aot.hints.reflective]]
=== `@Reflective`
{spring-framework-api}/aot/hint/annotation/Reflective.html[`@Reflective`] provides an idiomatic way to flag the need for reflection on an annotated element.
For instance, `@EventListener` is meta-annotated with `@Reflective` since the underlying implementation invokes the annotated method using reflection.
By default, only Spring beans are considered and an invocation hint is registered for the annotated element.
This can be tuned by specifying a custom `ReflectiveProcessor` implementation via the
`@Reflective` annotation.
Library authors can reuse this annotation for their own purposes.
If components other than Spring beans need to be processed, a `BeanFactoryInitializationAotProcessor` can detect the relevant types and use `ReflectiveRuntimeHintsRegistrar` to process them.
[[aot.hints.register-reflection-for-binding]]
=== `@RegisterReflectionForBinding`
{spring-framework-api}/aot/hint/annotation/RegisterReflectionForBinding.html[`@RegisterReflectionForBinding`] is a specialization of `@Reflective` that registers the need for serializing arbitrary types.
A typical use case is the use of DTOs that the container cannot infer, such as using a web client within a method body.
`@RegisterReflectionForBinding` can be applied to any Spring bean at the class level, but it can also be applied directly to a method, field, or constructor to better indicate where the hints are actually required.
The following example registers `Account` for serialization.
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
@Component
public class OrderService {
@RegisterReflectionForBinding(Account.class)
public void process(Order order) {
// ...
}
}
----
======
[[aot.hints.testing]]
=== Testing Runtime Hints
Spring Core also ships `RuntimeHintsPredicates`, a utility for checking that existing hints match a particular use case.
This can be used in your own tests to validate that a `RuntimeHintsRegistrar` contains the expected results.
We can write a test for our `SpellCheckService` and ensure that we will be able to load a dictionary at runtime:
include-code::./SpellCheckServiceTests[tag=hintspredicates]
With `RuntimeHintsPredicates`, we can check for reflection, resource, serialization, or proxy generation hints.
This approach works well for unit tests but implies that the runtime behavior of a component is well known.
You can learn more about the global runtime behavior of an application by running its test suite (or the app itself) with the {graalvm-docs}/native-image/metadata/AutomaticMetadataCollection/[GraalVM tracing agent].
This agent will record all relevant calls requiring GraalVM hints at runtime and write them out as JSON configuration files.
For more targeted discovery and testing, Spring Framework ships a dedicated module with core AOT testing utilities, `"org.springframework:spring-core-test"`.
This module contains the RuntimeHints Agent, a Java agent that records all method invocations that are related to runtime hints and helps you to assert that a given `RuntimeHints` instance covers all recorded invocations.
Let's consider a piece of infrastructure for which we'd like to test the hints we're contributing during the AOT processing phase.
include-code::./SampleReflection[]
We can then write a unit test (no native compilation required) that checks our contributed hints:
include-code::./SampleReflectionRuntimeHintsTests[]
If you forgot to contribute a hint, the test will fail and provide some details about the invocation:
[source,txt,indent=0,subs="verbatim,quotes"]
----
org.springframework.docs.core.aot.hints.testing.SampleReflection performReflection
INFO: Spring version:6.0.0-SNAPSHOT
Missing <"ReflectionHints"> for invocation <java.lang.Class#forName>
with arguments ["org.springframework.core.SpringVersion",
false,
jdk.internal.loader.ClassLoaders$AppClassLoader@251a69d7].
Stacktrace:
<"org.springframework.util.ClassUtils#forName, Line 284
io.spring.runtimehintstesting.SampleReflection#performReflection, Line 19
io.spring.runtimehintstesting.SampleReflectionRuntimeHintsTests#lambda$shouldRegisterReflectionHints$0, Line 25
----
There are various ways to configure this Java agent in your build, so please refer to the documentation of your build tool and test execution plugin.
The agent itself can be configured to instrument specific packages (by default, only `org.springframework` is instrumented).
You'll find more details in the {spring-framework-code}/buildSrc/README.md[Spring Framework `buildSrc` README] file.
@@ -1,7 +0,0 @@
[[appendix]]
= Appendix
:page-section-summary-toc: 1
@@ -1,57 +0,0 @@
[[application-startup-steps]]
= Application Startup Steps
This part of the appendix lists the existing `StartupSteps` that the core container is instrumented with.
WARNING: The name and detailed information about each startup step is not part of the public contract and
is subject to change; this is considered as an implementation detail of the core container and will follow
its behavior changes.
.Application startup steps defined in the core container
|===
| Name| Description| Tags
| `spring.beans.instantiate`
| Instantiation of a bean and its dependencies.
| `beanName` the name of the bean, `beanType` the type required at the injection point.
| `spring.beans.smart-initialize`
| Initialization of `SmartInitializingSingleton` beans.
| `beanName` the name of the bean.
| `spring.context.annotated-bean-reader.create`
| Creation of the `AnnotatedBeanDefinitionReader`.
|
| `spring.context.base-packages.scan`
| Scanning of base packages.
| `packages` array of base packages for scanning.
| `spring.context.beans.post-process`
| Beans post-processing phase.
|
| `spring.context.bean-factory.post-process`
| Invocation of the `BeanFactoryPostProcessor` beans.
| `postProcessor` the current post-processor.
| `spring.context.beandef-registry.post-process`
| Invocation of the `BeanDefinitionRegistryPostProcessor` beans.
| `postProcessor` the current post-processor.
| `spring.context.component-classes.register`
| Registration of component classes through `AnnotationConfigApplicationContext#register`.
| `classes` array of given classes for registration.
| `spring.context.config-classes.enhance`
| Enhancement of configuration classes with CGLIB proxies.
| `classCount` count of enhanced classes.
| `spring.context.config-classes.parse`
| Configuration classes parsing phase with the `ConfigurationClassPostProcessor`.
| `classCount` count of processed classes.
| `spring.context.refresh`
| Application context refresh phase.
|
|===
@@ -1,672 +0,0 @@
[[xsd-schemas]]
= XML Schemas
This part of the appendix lists XML schemas related to the core container.
[[xsd-schemas-util]]
== The `util` Schema
As the name implies, the `util` tags deal with common, utility configuration
issues, such as configuring collections, referencing constants, and so forth.
To use the tags in the `util` schema, you need to have the following preamble at the top
of your Spring XML configuration file (the text in the snippet references the
correct schema so that the tags in the `util` namespace are available to you):
[source,xml,indent=0,subs="verbatim,quotes"]
----
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:util="http://www.springframework.org/schema/util"
xsi:schemaLocation="
http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/util https://www.springframework.org/schema/util/spring-util.xsd">
<!-- bean definitions here -->
</beans>
----
[[xsd-schemas-util-constant]]
=== Using `<util:constant/>`
Consider the following bean definition:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean id="..." class="...">
<property name="isolation">
<bean id="java.sql.Connection.TRANSACTION_SERIALIZABLE"
class="org.springframework.beans.factory.config.FieldRetrievingFactoryBean" />
</property>
</bean>
----
The preceding configuration uses a Spring `FactoryBean` implementation (the
`FieldRetrievingFactoryBean`) to set the value of the `isolation` property on a bean
to the value of the `java.sql.Connection.TRANSACTION_SERIALIZABLE` constant. This is
all well and good, but it is verbose and (unnecessarily) exposes Spring's internal
plumbing to the end user.
The following XML Schema-based version is more concise, clearly expresses the
developer's intent ("`inject this constant value`"), and it reads better:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean id="..." class="...">
<property name="isolation">
<util:constant static-field="java.sql.Connection.TRANSACTION_SERIALIZABLE"/>
</property>
</bean>
----
[[xsd-schemas-util-frfb]]
==== Setting a Bean Property or Constructor Argument from a Field Value
{spring-framework-api}/beans/factory/config/FieldRetrievingFactoryBean.html[`FieldRetrievingFactoryBean`]
is a `FactoryBean` that retrieves a `static` or non-static field value. It is typically
used for retrieving `public` `static` `final` constants, which may then be used to set a
property value or constructor argument for another bean.
The following example shows how a `static` field is exposed, by using the
{spring-framework-api}/beans/factory/config/FieldRetrievingFactoryBean.html#setStaticField(java.lang.String)[`staticField`]
property:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean id="myField"
class="org.springframework.beans.factory.config.FieldRetrievingFactoryBean">
<property name="staticField" value="java.sql.Connection.TRANSACTION_SERIALIZABLE"/>
</bean>
----
There is also a convenience usage form where the `static` field is specified as the bean
name, as the following example shows:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean id="java.sql.Connection.TRANSACTION_SERIALIZABLE"
class="org.springframework.beans.factory.config.FieldRetrievingFactoryBean"/>
----
This does mean that there is no longer any choice in what the bean `id` is (so any other
bean that refers to it also has to use this longer name), but this form is very
concise to define and very convenient to use as an inner bean since the `id` does not have
to be specified for the bean reference, as the following example shows:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean id="..." class="...">
<property name="isolation">
<bean id="java.sql.Connection.TRANSACTION_SERIALIZABLE"
class="org.springframework.beans.factory.config.FieldRetrievingFactoryBean" />
</property>
</bean>
----
You can also access a non-static (instance) field of another bean, as
described in the API documentation for the
{spring-framework-api}/beans/factory/config/FieldRetrievingFactoryBean.html[`FieldRetrievingFactoryBean`]
class.
Injecting enumeration values into beans as either property or constructor arguments is
easy to do in Spring. You do not actually have to do anything or know anything about
the Spring internals (or even about classes such as the `FieldRetrievingFactoryBean`).
The following example enumeration shows how easy injecting an enum value is:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary",chomp="-packages"]
----
package jakarta.persistence;
public enum PersistenceContextType {
TRANSACTION,
EXTENDED
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary",chomp="-packages"]
----
package jakarta.persistence
enum class PersistenceContextType {
TRANSACTION,
EXTENDED
}
----
======
Now consider the following setter of type `PersistenceContextType` and the corresponding bean definition:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary",chomp="-packages"]
----
package example;
public class Client {
private PersistenceContextType persistenceContextType;
public void setPersistenceContextType(PersistenceContextType type) {
this.persistenceContextType = type;
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary",chomp="-packages"]
----
package example
class Client {
lateinit var persistenceContextType: PersistenceContextType
}
----
======
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean class="example.Client">
<property name="persistenceContextType" value="TRANSACTION"/>
</bean>
----
[[xsd-schemas-util-property-path]]
=== Using `<util:property-path/>`
Consider the following example:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<!-- target bean to be referenced by name -->
<bean id="testBean" class="org.springframework.beans.TestBean" scope="prototype">
<property name="age" value="10"/>
<property name="spouse">
<bean class="org.springframework.beans.TestBean">
<property name="age" value="11"/>
</bean>
</property>
</bean>
<!-- results in 10, which is the value of property 'age' of bean 'testBean' -->
<bean id="testBean.age" class="org.springframework.beans.factory.config.PropertyPathFactoryBean"/>
----
The preceding configuration uses a Spring `FactoryBean` implementation (the
`PropertyPathFactoryBean`) to create a bean (of type `int`) called `testBean.age` that
has a value equal to the `age` property of the `testBean` bean.
Now consider the following example, which adds a `<util:property-path/>` element:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<!-- target bean to be referenced by name -->
<bean id="testBean" class="org.springframework.beans.TestBean" scope="prototype">
<property name="age" value="10"/>
<property name="spouse">
<bean class="org.springframework.beans.TestBean">
<property name="age" value="11"/>
</bean>
</property>
</bean>
<!-- results in 10, which is the value of property 'age' of bean 'testBean' -->
<util:property-path id="name" path="testBean.age"/>
----
The value of the `path` attribute of the `<property-path/>` element follows the form of
`beanName.beanProperty`. In this case, it picks up the `age` property of the bean named
`testBean`. The value of that `age` property is `10`.
[[xsd-schemas-util-property-path-dependency]]
==== Using `<util:property-path/>` to Set a Bean Property or Constructor Argument
`PropertyPathFactoryBean` is a `FactoryBean` that evaluates a property path on a given
target object. The target object can be specified directly or by a bean name. You can then use this
value in another bean definition as a property value or constructor
argument.
The following example shows a path being used against another bean, by name:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<!-- target bean to be referenced by name -->
<bean id="person" class="org.springframework.beans.TestBean" scope="prototype">
<property name="age" value="10"/>
<property name="spouse">
<bean class="org.springframework.beans.TestBean">
<property name="age" value="11"/>
</bean>
</property>
</bean>
<!-- results in 11, which is the value of property 'spouse.age' of bean 'person' -->
<bean id="theAge"
class="org.springframework.beans.factory.config.PropertyPathFactoryBean">
<property name="targetBeanName" value="person"/>
<property name="propertyPath" value="spouse.age"/>
</bean>
----
In the following example, a path is evaluated against an inner bean:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<!-- results in 12, which is the value of property 'age' of the inner bean -->
<bean id="theAge"
class="org.springframework.beans.factory.config.PropertyPathFactoryBean">
<property name="targetObject">
<bean class="org.springframework.beans.TestBean">
<property name="age" value="12"/>
</bean>
</property>
<property name="propertyPath" value="age"/>
</bean>
----
There is also a shortcut form, where the bean name is the property path.
The following example shows the shortcut form:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<!-- results in 10, which is the value of property 'age' of bean 'person' -->
<bean id="person.age"
class="org.springframework.beans.factory.config.PropertyPathFactoryBean"/>
----
This form does mean that there is no choice in the name of the bean. Any reference to it
also has to use the same `id`, which is the path. If used as an inner
bean, there is no need to refer to it at all, as the following example shows:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean id="..." class="...">
<property name="age">
<bean id="person.age"
class="org.springframework.beans.factory.config.PropertyPathFactoryBean"/>
</property>
</bean>
----
You can specifically set the result type in the actual definition. This is not necessary
for most use cases, but it can sometimes be useful. See the javadoc for more info on
this feature.
[[xsd-schemas-util-properties]]
=== Using `<util:properties/>`
Consider the following example:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<!-- creates a java.util.Properties instance with values loaded from the supplied location -->
<bean id="jdbcConfiguration" class="org.springframework.beans.factory.config.PropertiesFactoryBean">
<property name="location" value="classpath:com/foo/jdbc-production.properties"/>
</bean>
----
The preceding configuration uses a Spring `FactoryBean` implementation (the
`PropertiesFactoryBean`) to instantiate a `java.util.Properties` instance with values
loaded from the supplied xref:web/webflux-webclient/client-builder.adoc#webflux-client-builder-reactor-resources[`Resource`] location).
The following example uses a `util:properties` element to make a more concise representation:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<!-- creates a java.util.Properties instance with values loaded from the supplied location -->
<util:properties id="jdbcConfiguration" location="classpath:com/foo/jdbc-production.properties"/>
----
[[xsd-schemas-util-list]]
=== Using `<util:list/>`
Consider the following example:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<!-- creates a java.util.List instance with values loaded from the supplied 'sourceList' -->
<bean id="emails" class="org.springframework.beans.factory.config.ListFactoryBean">
<property name="sourceList">
<list>
<value>pechorin@hero.org</value>
<value>raskolnikov@slums.org</value>
<value>stavrogin@gov.org</value>
<value>porfiry@gov.org</value>
</list>
</property>
</bean>
----
The preceding configuration uses a Spring `FactoryBean` implementation (the
`ListFactoryBean`) to create a `java.util.List` instance and initialize it with values taken
from the supplied `sourceList`.
The following example uses a `<util:list/>` element to make a more concise representation:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<!-- creates a java.util.List instance with the supplied values -->
<util:list id="emails">
<value>pechorin@hero.org</value>
<value>raskolnikov@slums.org</value>
<value>stavrogin@gov.org</value>
<value>porfiry@gov.org</value>
</util:list>
----
You can also explicitly control the exact type of `List` that is instantiated and
populated by using the `list-class` attribute on the `<util:list/>` element. For
example, if we really need a `java.util.LinkedList` to be instantiated, we could use the
following configuration:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<util:list id="emails" list-class="java.util.LinkedList">
<value>jackshaftoe@vagabond.org</value>
<value>eliza@thinkingmanscrumpet.org</value>
<value>vanhoek@pirate.org</value>
<value>d'Arcachon@nemesis.org</value>
</util:list>
----
If no `list-class` attribute is supplied, the container chooses a `List` implementation.
[[xsd-schemas-util-map]]
=== Using `<util:map/>`
Consider the following example:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<!-- creates a java.util.Map instance with values loaded from the supplied 'sourceMap' -->
<bean id="emails" class="org.springframework.beans.factory.config.MapFactoryBean">
<property name="sourceMap">
<map>
<entry key="pechorin" value="pechorin@hero.org"/>
<entry key="raskolnikov" value="raskolnikov@slums.org"/>
<entry key="stavrogin" value="stavrogin@gov.org"/>
<entry key="porfiry" value="porfiry@gov.org"/>
</map>
</property>
</bean>
----
The preceding configuration uses a Spring `FactoryBean` implementation (the
`MapFactoryBean`) to create a `java.util.Map` instance initialized with key-value pairs
taken from the supplied `'sourceMap'`.
The following example uses a `<util:map/>` element to make a more concise representation:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<!-- creates a java.util.Map instance with the supplied key-value pairs -->
<util:map id="emails">
<entry key="pechorin" value="pechorin@hero.org"/>
<entry key="raskolnikov" value="raskolnikov@slums.org"/>
<entry key="stavrogin" value="stavrogin@gov.org"/>
<entry key="porfiry" value="porfiry@gov.org"/>
</util:map>
----
You can also explicitly control the exact type of `Map` that is instantiated and
populated by using the `'map-class'` attribute on the `<util:map/>` element. For
example, if we really need a `java.util.TreeMap` to be instantiated, we could use the
following configuration:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<util:map id="emails" map-class="java.util.TreeMap">
<entry key="pechorin" value="pechorin@hero.org"/>
<entry key="raskolnikov" value="raskolnikov@slums.org"/>
<entry key="stavrogin" value="stavrogin@gov.org"/>
<entry key="porfiry" value="porfiry@gov.org"/>
</util:map>
----
If no `'map-class'` attribute is supplied, the container chooses a `Map` implementation.
[[xsd-schemas-util-set]]
=== Using `<util:set/>`
Consider the following example:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<!-- creates a java.util.Set instance with values loaded from the supplied 'sourceSet' -->
<bean id="emails" class="org.springframework.beans.factory.config.SetFactoryBean">
<property name="sourceSet">
<set>
<value>pechorin@hero.org</value>
<value>raskolnikov@slums.org</value>
<value>stavrogin@gov.org</value>
<value>porfiry@gov.org</value>
</set>
</property>
</bean>
----
The preceding configuration uses a Spring `FactoryBean` implementation (the
`SetFactoryBean`) to create a `java.util.Set` instance initialized with values taken
from the supplied `sourceSet`.
The following example uses a `<util:set/>` element to make a more concise representation:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<!-- creates a java.util.Set instance with the supplied values -->
<util:set id="emails">
<value>pechorin@hero.org</value>
<value>raskolnikov@slums.org</value>
<value>stavrogin@gov.org</value>
<value>porfiry@gov.org</value>
</util:set>
----
You can also explicitly control the exact type of `Set` that is instantiated and
populated by using the `set-class` attribute on the `<util:set/>` element. For
example, if we really need a `java.util.TreeSet` to be instantiated, we could use the
following configuration:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<util:set id="emails" set-class="java.util.TreeSet">
<value>pechorin@hero.org</value>
<value>raskolnikov@slums.org</value>
<value>stavrogin@gov.org</value>
<value>porfiry@gov.org</value>
</util:set>
----
If no `set-class` attribute is supplied, the container chooses a `Set` implementation.
[[xsd-schemas-aop]]
== The `aop` Schema
The `aop` tags deal with configuring all things AOP in Spring, including Spring's
own proxy-based AOP framework and Spring's integration with the AspectJ AOP framework.
These tags are comprehensively covered in the chapter entitled xref:core/aop.adoc[Aspect Oriented Programming with Spring]
.
In the interest of completeness, to use the tags in the `aop` schema, you need to have
the following preamble at the top of your Spring XML configuration file (the text in the
snippet references the correct schema so that the tags in the `aop` namespace
are available to you):
[source,xml,indent=0,subs="verbatim,quotes"]
----
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="
http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/aop https://www.springframework.org/schema/aop/spring-aop.xsd">
<!-- bean definitions here -->
</beans>
----
[[xsd-schemas-context]]
== The `context` Schema
The `context` tags deal with `ApplicationContext` configuration that relates to plumbing
-- that is, not usually beans that are important to an end-user but rather beans that do
a lot of the "`grunt`" work in Spring, such as `BeanfactoryPostProcessors`. The following
snippet references the correct schema so that the elements in the `context` namespace are
available to you:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="
http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd">
<!-- bean definitions here -->
</beans>
----
[[xsd-schemas-context-pphc]]
=== Using `<property-placeholder/>`
This element activates the replacement of `${...}` placeholders, which are resolved against a
specified properties file (as a xref:web/webflux-webclient/client-builder.adoc#webflux-client-builder-reactor-resources[Spring resource location]). This element
is a convenience mechanism that sets up a xref:core/beans/factory-extension.adoc#beans-factory-placeholderconfigurer[`PropertySourcesPlaceholderConfigurer`]
for you. If you need more control over the specific
`PropertySourcesPlaceholderConfigurer` setup, you can explicitly define it as a bean yourself.
[WARNING]
=====
Only one such element should be defined for a given application with the properties
that it needs. Several property placeholders can be configured as long as they have distinct
placeholder syntax (`${...}`).
If you need to modularize the source of properties used for the replacement, you should
not create multiple properties placeholders. Rather, each module should contribute a
`PropertySource` to the `Environment`. Alternatively, you can create your own
`PropertySourcesPlaceholderConfigurer` bean that gathers the properties to use.
=====
[[xsd-schemas-context-ac]]
=== Using `<annotation-config/>`
This element activates the Spring infrastructure to detect annotations in bean classes:
* Spring's xref:core/beans/basics.adoc#beans-factory-metadata[`@Configuration`] model
* xref:core/beans/annotation-config.adoc[`@Autowired`/`@Inject`], `@Value`, and `@Lookup`
* JSR-250's `@Resource`, `@PostConstruct`, and `@PreDestroy` (if available)
* JAX-WS's `@WebServiceRef` and EJB 3's `@EJB` (if available)
* JPA's `@PersistenceContext` and `@PersistenceUnit` (if available)
* Spring's xref:core/beans/context-introduction.adoc#context-functionality-events-annotation[`@EventListener`]
Alternatively, you can choose to explicitly activate the individual `BeanPostProcessors`
for those annotations.
NOTE: This element does not activate processing of Spring's
xref:data-access/transaction/declarative/annotations.adoc[`@Transactional`] annotation;
you can use the <<data-access.adoc#tx-decl-explained, `<tx:annotation-driven/>`>>
element for that purpose. Similarly, Spring's
xref:integration/cache/annotations.adoc[caching annotations] need to be explicitly
xref:integration/cache/annotations.adoc#cache-annotation-enable[enabled] as well.
[[xsd-schemas-context-component-scan]]
=== Using `<component-scan/>`
This element is detailed in the section on xref:core/beans/annotation-config.adoc[annotation-based container configuration]
.
[[xsd-schemas-context-ltw]]
=== Using `<load-time-weaver/>`
This element is detailed in the section on xref:core/aop/using-aspectj.adoc#aop-aj-ltw[load-time weaving with AspectJ in the Spring Framework]
.
[[xsd-schemas-context-sc]]
=== Using `<spring-configured/>`
This element is detailed in the section on xref:core/aop/using-aspectj.adoc#aop-atconfigurable[using AspectJ to dependency inject domain objects with Spring]
.
[[xsd-schemas-context-mbe]]
=== Using `<mbean-export/>`
This element is detailed in the section on xref:integration/jmx/naming.adoc#jmx-context-mbeanexport[configuring annotation-based MBean export]
.
[[xsd-schemas-beans]]
== The Beans Schema
Last but not least, we have the elements in the `beans` schema. These elements
have been in Spring since the very dawn of the framework. Examples of the various elements
in the `beans` schema are not shown here because they are quite comprehensively covered
in xref:core/beans/dependencies/factory-properties-detailed.adoc[dependencies and configuration in detail]
(and, indeed, in that entire xref:web/webmvc-view/mvc-xslt.adoc#mvc-view-xslt-beandefs[chapter]).
Note that you can add zero or more key-value pairs to `<bean/>` XML definitions.
What, if anything, is done with this extra metadata is totally up to your own custom
logic (and so is typically only of use if you write your own custom elements as described
in the appendix entitled xref:core/appendix/xml-custom.adoc[XML Schema Authoring]).
The following example shows the `<meta/>` element in the context of a surrounding `<bean/>`
(note that, without any logic to interpret it, the metadata is effectively useless
as it stands).
[source,xml,indent=0,subs="verbatim,quotes"]
----
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="
http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd">
<bean id="foo" class="x.y.Foo">
<meta key="cacheName" value="foo"/> <1>
<property name="name" value="Rick"/>
</bean>
</beans>
----
<1> This is the example `meta` element
In the case of the preceding example, you could assume that there is some logic that consumes
the bean definition and sets up some caching infrastructure that uses the supplied metadata.
@@ -1,9 +0,0 @@
[[beans]]
= The IoC Container
:page-section-summary-toc: 1
This chapter covers Spring's Inversion of Control (IoC) container.
@@ -1,81 +0,0 @@
[[beans-annotation-config]]
= Annotation-based Container Configuration
.Are annotations better than XML for configuring Spring?
****
The introduction of annotation-based configuration raised the question of whether this
approach is "`better`" than XML. The short answer is "`it depends.`" The long answer is
that each approach has its pros and cons, and, usually, it is up to the developer to
decide which strategy suits them better. Due to the way they are defined, annotations
provide a lot of context in their declaration, leading to shorter and more concise
configuration. However, XML excels at wiring up components without touching their source
code or recompiling them. Some developers prefer having the wiring close to the source
while others argue that annotated classes are no longer POJOs and, furthermore, that the
configuration becomes decentralized and harder to control.
No matter the choice, Spring can accommodate both styles and even mix them together.
It is worth pointing out that through its xref:core/beans/java.adoc[JavaConfig] option, Spring lets
annotations be used in a non-invasive way, without touching the target components'
source code and that, in terms of tooling, all configuration styles are supported by
{spring-site-tools}[Spring Tools] for Eclipse, Visual Studio Code, and Theia.
****
An alternative to XML setup is provided by annotation-based configuration, which relies
on bytecode metadata for wiring up components instead of XML declarations. Instead of
using XML to describe a bean wiring, the developer moves the configuration into the
component class itself by using annotations on the relevant class, method, or field
declaration. As mentioned in xref:core/beans/factory-extension.adoc#beans-factory-extension-bpp-examples-aabpp[Example: The `AutowiredAnnotationBeanPostProcessor`], using a
`BeanPostProcessor` in conjunction with annotations is a common means of extending the
Spring IoC container. For example, the xref:core/beans/annotation-config/autowired.adoc[`@Autowired`]
annotation provides the same capabilities as described in xref:core/beans/dependencies/factory-autowire.adoc[Autowiring Collaborators] but
with more fine-grained control and wider applicability. In addition, Spring provides
support for JSR-250 annotations, such as `@PostConstruct` and `@PreDestroy`, as well as
support for JSR-330 (Dependency Injection for Java) annotations contained in the
`jakarta.inject` package such as `@Inject` and `@Named`. Details about those annotations
can be found in the xref:core/beans/standard-annotations.adoc[relevant section].
[NOTE]
====
Annotation injection is performed before XML injection. Thus, the XML configuration
overrides the annotations for properties wired through both approaches.
====
As always, you can register the post-processors as individual bean definitions, but they
can also be implicitly registered by including the following tag in an XML-based Spring
configuration (notice the inclusion of the `context` namespace):
[source,xml,indent=0,subs="verbatim,quotes"]
----
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
https://www.springframework.org/schema/context/spring-context.xsd">
<context:annotation-config/>
</beans>
----
The `<context:annotation-config/>` element implicitly registers the following post-processors:
* {spring-framework-api}/context/annotation/ConfigurationClassPostProcessor.html[`ConfigurationClassPostProcessor`]
* {spring-framework-api}/beans/factory/annotation/AutowiredAnnotationBeanPostProcessor.html[`AutowiredAnnotationBeanPostProcessor`]
* {spring-framework-api}/context/annotation/CommonAnnotationBeanPostProcessor.html[`CommonAnnotationBeanPostProcessor`]
* {spring-framework-api}/orm/jpa/support/PersistenceAnnotationBeanPostProcessor.html[`PersistenceAnnotationBeanPostProcessor`]
* {spring-framework-api}/context/event/EventListenerMethodProcessor.html[`EventListenerMethodProcessor`]
[NOTE]
====
`<context:annotation-config/>` only looks for annotations on beans in the same
application context in which it is defined. This means that, if you put
`<context:annotation-config/>` in a `WebApplicationContext` for a `DispatcherServlet`,
it only checks for `@Autowired` beans in your controllers, and not your services. See
xref:web/webmvc/mvc-servlet.adoc[The DispatcherServlet] for more information.
====
@@ -1,114 +0,0 @@
[[beans-autowired-annotation-primary]]
= Fine-tuning Annotation-based Autowiring with `@Primary`
Because autowiring by type may lead to multiple candidates, it is often necessary to have
more control over the selection process. One way to accomplish this is with Spring's
`@Primary` annotation. `@Primary` indicates that a particular bean should be given
preference when multiple beans are candidates to be autowired to a single-valued
dependency. If exactly one primary bean exists among the candidates, it becomes the
autowired value.
Consider the following configuration that defines `firstMovieCatalog` as the
primary `MovieCatalog`:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
@Configuration
public class MovieConfiguration {
@Bean
@Primary
public MovieCatalog firstMovieCatalog() { ... }
@Bean
public MovieCatalog secondMovieCatalog() { ... }
// ...
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
@Configuration
class MovieConfiguration {
@Bean
@Primary
fun firstMovieCatalog(): MovieCatalog { ... }
@Bean
fun secondMovieCatalog(): MovieCatalog { ... }
// ...
}
----
======
With the preceding configuration, the following `MovieRecommender` is autowired with the
`firstMovieCatalog`:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class MovieRecommender {
@Autowired
private MovieCatalog movieCatalog;
// ...
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class MovieRecommender {
@Autowired
private lateinit var movieCatalog: MovieCatalog
// ...
}
----
======
The corresponding bean definitions follow:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
https://www.springframework.org/schema/context/spring-context.xsd">
<context:annotation-config/>
<bean class="example.SimpleMovieCatalog" primary="true">
<!-- inject any dependencies required by this bean -->
</bean>
<bean class="example.SimpleMovieCatalog">
<!-- inject any dependencies required by this bean -->
</bean>
<bean id="movieRecommender" class="example.MovieRecommender"/>
</beans>
----
@@ -1,585 +0,0 @@
[[beans-autowired-annotation-qualifiers]]
= Fine-tuning Annotation-based Autowiring with Qualifiers
`@Primary` is an effective way to use autowiring by type with several instances when one
primary candidate can be determined. When you need more control over the selection process,
you can use Spring's `@Qualifier` annotation. You can associate qualifier values
with specific arguments, narrowing the set of type matches so that a specific bean is
chosen for each argument. In the simplest case, this can be a plain descriptive value, as
shown in the following example:
--
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class MovieRecommender {
@Autowired
@Qualifier("main")
private MovieCatalog movieCatalog;
// ...
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class MovieRecommender {
@Autowired
@Qualifier("main")
private lateinit var movieCatalog: MovieCatalog
// ...
}
----
======
--
You can also specify the `@Qualifier` annotation on individual constructor arguments or
method parameters, as shown in the following example:
--
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class MovieRecommender {
private final MovieCatalog movieCatalog;
private final CustomerPreferenceDao customerPreferenceDao;
@Autowired
public void prepare(@Qualifier("main") MovieCatalog movieCatalog,
CustomerPreferenceDao customerPreferenceDao) {
this.movieCatalog = movieCatalog;
this.customerPreferenceDao = customerPreferenceDao;
}
// ...
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class MovieRecommender {
private lateinit var movieCatalog: MovieCatalog
private lateinit var customerPreferenceDao: CustomerPreferenceDao
@Autowired
fun prepare(@Qualifier("main") movieCatalog: MovieCatalog,
customerPreferenceDao: CustomerPreferenceDao) {
this.movieCatalog = movieCatalog
this.customerPreferenceDao = customerPreferenceDao
}
// ...
}
----
======
--
The following example shows corresponding bean definitions.
--
[source,xml,indent=0,subs="verbatim,quotes"]
----
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
https://www.springframework.org/schema/context/spring-context.xsd">
<context:annotation-config/>
<bean class="example.SimpleMovieCatalog">
<qualifier value="main"/> <1>
<!-- inject any dependencies required by this bean -->
</bean>
<bean class="example.SimpleMovieCatalog">
<qualifier value="action"/> <2>
<!-- inject any dependencies required by this bean -->
</bean>
<bean id="movieRecommender" class="example.MovieRecommender"/>
</beans>
----
<1> The bean with the `main` qualifier value is wired with the constructor argument that
is qualified with the same value.
<2> The bean with the `action` qualifier value is wired with the constructor argument that
is qualified with the same value.
--
For a fallback match, the bean name is considered a default qualifier value. Thus, you
can define the bean with an `id` of `main` instead of the nested qualifier element, leading
to the same matching result. However, although you can use this convention to refer to
specific beans by name, `@Autowired` is fundamentally about type-driven injection with
optional semantic qualifiers. This means that qualifier values, even with the bean name
fallback, always have narrowing semantics within the set of type matches. They do not
semantically express a reference to a unique bean `id`. Good qualifier values are `main`
or `EMEA` or `persistent`, expressing characteristics of a specific component that are
independent from the bean `id`, which may be auto-generated in case of an anonymous bean
definition such as the one in the preceding example.
Qualifiers also apply to typed collections, as discussed earlier -- for example, to
`Set<MovieCatalog>`. In this case, all matching beans, according to the declared
qualifiers, are injected as a collection. This implies that qualifiers do not have to be
unique. Rather, they constitute filtering criteria. For example, you can define
multiple `MovieCatalog` beans with the same qualifier value "`action`", all of which are
injected into a `Set<MovieCatalog>` annotated with `@Qualifier("action")`.
[TIP]
====
Letting qualifier values select against target bean names, within the type-matching
candidates, does not require a `@Qualifier` annotation at the injection point.
If there is no other resolution indicator (such as a qualifier or a primary marker),
for a non-unique dependency situation, Spring matches the injection point name
(that is, the field name or parameter name) against the target bean names and chooses the
same-named candidate, if any.
====
That said, if you intend to express annotation-driven injection by name, do not
primarily use `@Autowired`, even if it is capable of selecting by bean name among
type-matching candidates. Instead, use the JSR-250 `@Resource` annotation, which is
semantically defined to identify a specific target component by its unique name, with
the declared type being irrelevant for the matching process. `@Autowired` has rather
different semantics: After selecting candidate beans by type, the specified `String`
qualifier value is considered within those type-selected candidates only (for example,
matching an `account` qualifier against beans marked with the same qualifier label).
For beans that are themselves defined as a collection, `Map`, or array type, `@Resource`
is a fine solution, referring to the specific collection or array bean by unique name.
That said, as of 4.3, you can match collection, `Map`, and array types through Spring's
`@Autowired` type matching algorithm as well, as long as the element type information
is preserved in `@Bean` return type signatures or collection inheritance hierarchies.
In this case, you can use qualifier values to select among same-typed collections,
as outlined in the previous paragraph.
As of 4.3, `@Autowired` also considers self references for injection (that is, references
back to the bean that is currently injected). Note that self injection is a fallback.
Regular dependencies on other components always have precedence. In that sense, self
references do not participate in regular candidate selection and are therefore in
particular never primary. On the contrary, they always end up as lowest precedence.
In practice, you should use self references as a last resort only (for example, for
calling other methods on the same instance through the bean's transactional proxy).
Consider factoring out the affected methods to a separate delegate bean in such a scenario.
Alternatively, you can use `@Resource`, which may obtain a proxy back to the current bean
by its unique name.
[NOTE]
====
Trying to inject the results from `@Bean` methods on the same configuration class is
effectively a self-reference scenario as well. Either lazily resolve such references
in the method signature where it is actually needed (as opposed to an autowired field
in the configuration class) or declare the affected `@Bean` methods as `static`,
decoupling them from the containing configuration class instance and its lifecycle.
Otherwise, such beans are only considered in the fallback phase, with matching beans
on other configuration classes selected as primary candidates instead (if available).
====
`@Autowired` applies to fields, constructors, and multi-argument methods, allowing for
narrowing through qualifier annotations at the parameter level. In contrast, `@Resource`
is supported only for fields and bean property setter methods with a single argument.
As a consequence, you should stick with qualifiers if your injection target is a
constructor or a multi-argument method.
You can create your own custom qualifier annotations. To do so, define an annotation and
provide the `@Qualifier` annotation within your definition, as the following example shows:
--
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
@Target({ElementType.FIELD, ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
@Qualifier
public @interface Genre {
String value();
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
@Target(AnnotationTarget.FIELD, AnnotationTarget.VALUE_PARAMETER)
@Retention(AnnotationRetention.RUNTIME)
@Qualifier
annotation class Genre(val value: String)
----
======
--
Then you can provide the custom qualifier on autowired fields and parameters, as the
following example shows:
--
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class MovieRecommender {
@Autowired
@Genre("Action")
private MovieCatalog actionCatalog;
private MovieCatalog comedyCatalog;
@Autowired
public void setComedyCatalog(@Genre("Comedy") MovieCatalog comedyCatalog) {
this.comedyCatalog = comedyCatalog;
}
// ...
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class MovieRecommender {
@Autowired
@Genre("Action")
private lateinit var actionCatalog: MovieCatalog
private lateinit var comedyCatalog: MovieCatalog
@Autowired
fun setComedyCatalog(@Genre("Comedy") comedyCatalog: MovieCatalog) {
this.comedyCatalog = comedyCatalog
}
// ...
}
----
======
--
Next, you can provide the information for the candidate bean definitions. You can add
`<qualifier/>` tags as sub-elements of the `<bean/>` tag and then specify the `type` and
`value` to match your custom qualifier annotations. The type is matched against the
fully-qualified class name of the annotation. Alternately, as a convenience if no risk of
conflicting names exists, you can use the short class name. The following example
demonstrates both approaches:
--
[source,xml,indent=0,subs="verbatim,quotes"]
----
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
https://www.springframework.org/schema/context/spring-context.xsd">
<context:annotation-config/>
<bean class="example.SimpleMovieCatalog">
<qualifier type="Genre" value="Action"/>
<!-- inject any dependencies required by this bean -->
</bean>
<bean class="example.SimpleMovieCatalog">
<qualifier type="example.Genre" value="Comedy"/>
<!-- inject any dependencies required by this bean -->
</bean>
<bean id="movieRecommender" class="example.MovieRecommender"/>
</beans>
----
--
In xref:core/beans/classpath-scanning.adoc[Classpath Scanning and Managed Components], you can see an annotation-based alternative to
providing the qualifier metadata in XML. Specifically, see xref:core/beans/classpath-scanning.adoc#beans-scanning-qualifiers[Providing Qualifier Metadata with Annotations].
In some cases, using an annotation without a value may suffice. This can be
useful when the annotation serves a more generic purpose and can be applied across
several different types of dependencies. For example, you may provide an offline
catalog that can be searched when no Internet connection is available. First, define
the simple annotation, as the following example shows:
--
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
@Target({ElementType.FIELD, ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
@Qualifier
public @interface Offline {
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
@Target(AnnotationTarget.FIELD, AnnotationTarget.VALUE_PARAMETER)
@Retention(AnnotationRetention.RUNTIME)
@Qualifier
annotation class Offline
----
======
--
Then add the annotation to the field or property to be autowired, as shown in the
following example:
--
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class MovieRecommender {
@Autowired
@Offline // <1>
private MovieCatalog offlineCatalog;
// ...
}
----
<1> This line adds the `@Offline` annotation.
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class MovieRecommender {
@Autowired
@Offline // <1>
private lateinit var offlineCatalog: MovieCatalog
// ...
}
----
<1> This line adds the `@Offline` annotation.
======
--
Now the bean definition only needs a qualifier `type`, as shown in the following example:
--
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean class="example.SimpleMovieCatalog">
<qualifier type="Offline"/> <1>
<!-- inject any dependencies required by this bean -->
</bean>
----
<1> This element specifies the qualifier.
--
You can also define custom qualifier annotations that accept named attributes in
addition to or instead of the simple `value` attribute. If multiple attribute values are
then specified on a field or parameter to be autowired, a bean definition must match
all such attribute values to be considered an autowire candidate. As an example,
consider the following annotation definition:
--
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
@Target({ElementType.FIELD, ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
@Qualifier
public @interface MovieQualifier {
String genre();
Format format();
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
@Target(AnnotationTarget.FIELD, AnnotationTarget.VALUE_PARAMETER)
@Retention(AnnotationRetention.RUNTIME)
@Qualifier
annotation class MovieQualifier(val genre: String, val format: Format)
----
======
--
In this case `Format` is an enum, defined as follows:
--
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public enum Format {
VHS, DVD, BLURAY
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
enum class Format {
VHS, DVD, BLURAY
}
----
======
--
The fields to be autowired are annotated with the custom qualifier and include values
for both attributes: `genre` and `format`, as the following example shows:
--
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class MovieRecommender {
@Autowired
@MovieQualifier(format=Format.VHS, genre="Action")
private MovieCatalog actionVhsCatalog;
@Autowired
@MovieQualifier(format=Format.VHS, genre="Comedy")
private MovieCatalog comedyVhsCatalog;
@Autowired
@MovieQualifier(format=Format.DVD, genre="Action")
private MovieCatalog actionDvdCatalog;
@Autowired
@MovieQualifier(format=Format.BLURAY, genre="Comedy")
private MovieCatalog comedyBluRayCatalog;
// ...
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class MovieRecommender {
@Autowired
@MovieQualifier(format = Format.VHS, genre = "Action")
private lateinit var actionVhsCatalog: MovieCatalog
@Autowired
@MovieQualifier(format = Format.VHS, genre = "Comedy")
private lateinit var comedyVhsCatalog: MovieCatalog
@Autowired
@MovieQualifier(format = Format.DVD, genre = "Action")
private lateinit var actionDvdCatalog: MovieCatalog
@Autowired
@MovieQualifier(format = Format.BLURAY, genre = "Comedy")
private lateinit var comedyBluRayCatalog: MovieCatalog
// ...
}
----
======
--
Finally, the bean definitions should contain matching qualifier values. This example
also demonstrates that you can use bean meta attributes instead of the
`<qualifier/>` elements. If available, the `<qualifier/>` element and its attributes take
precedence, but the autowiring mechanism falls back on the values provided within the
`<meta/>` tags if no such qualifier is present, as in the last two bean definitions in
the following example:
--
[source,xml,indent=0,subs="verbatim,quotes"]
----
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
https://www.springframework.org/schema/context/spring-context.xsd">
<context:annotation-config/>
<bean class="example.SimpleMovieCatalog">
<qualifier type="MovieQualifier">
<attribute key="format" value="VHS"/>
<attribute key="genre" value="Action"/>
</qualifier>
<!-- inject any dependencies required by this bean -->
</bean>
<bean class="example.SimpleMovieCatalog">
<qualifier type="MovieQualifier">
<attribute key="format" value="VHS"/>
<attribute key="genre" value="Comedy"/>
</qualifier>
<!-- inject any dependencies required by this bean -->
</bean>
<bean class="example.SimpleMovieCatalog">
<meta key="format" value="DVD"/>
<meta key="genre" value="Action"/>
<!-- inject any dependencies required by this bean -->
</bean>
<bean class="example.SimpleMovieCatalog">
<meta key="format" value="BLURAY"/>
<meta key="genre" value="Comedy"/>
<!-- inject any dependencies required by this bean -->
</bean>
</beans>
----
--
@@ -1,490 +0,0 @@
[[beans-autowired-annotation]]
= Using `@Autowired`
[NOTE]
====
JSR 330's `@Inject` annotation can be used in place of Spring's `@Autowired` annotation in the
examples included in this section. See xref:core/beans/standard-annotations.adoc[here] for more details.
====
You can apply the `@Autowired` annotation to constructors, as the following example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class MovieRecommender {
private final CustomerPreferenceDao customerPreferenceDao;
@Autowired
public MovieRecommender(CustomerPreferenceDao customerPreferenceDao) {
this.customerPreferenceDao = customerPreferenceDao;
}
// ...
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class MovieRecommender @Autowired constructor(
private val customerPreferenceDao: CustomerPreferenceDao)
----
======
[NOTE]
====
As of Spring Framework 4.3, an `@Autowired` annotation on such a constructor is no longer
necessary if the target bean defines only one constructor to begin with. However, if
several constructors are available and there is no primary/default constructor, at least
one of the constructors must be annotated with `@Autowired` in order to instruct the
container which one to use. See the discussion on
xref:core/beans/annotation-config/autowired.adoc#beans-autowired-annotation-constructor-resolution[constructor resolution] for details.
====
You can also apply the `@Autowired` annotation to _traditional_ setter methods,
as the following example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class SimpleMovieLister {
private MovieFinder movieFinder;
@Autowired
public void setMovieFinder(MovieFinder movieFinder) {
this.movieFinder = movieFinder;
}
// ...
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class SimpleMovieLister {
@set:Autowired
lateinit var movieFinder: MovieFinder
// ...
}
----
======
You can also apply the annotation to methods with arbitrary names and multiple
arguments, as the following example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class MovieRecommender {
private MovieCatalog movieCatalog;
private CustomerPreferenceDao customerPreferenceDao;
@Autowired
public void prepare(MovieCatalog movieCatalog,
CustomerPreferenceDao customerPreferenceDao) {
this.movieCatalog = movieCatalog;
this.customerPreferenceDao = customerPreferenceDao;
}
// ...
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class MovieRecommender {
private lateinit var movieCatalog: MovieCatalog
private lateinit var customerPreferenceDao: CustomerPreferenceDao
@Autowired
fun prepare(movieCatalog: MovieCatalog,
customerPreferenceDao: CustomerPreferenceDao) {
this.movieCatalog = movieCatalog
this.customerPreferenceDao = customerPreferenceDao
}
// ...
}
----
======
You can apply `@Autowired` to fields as well and even mix it with constructors, as the
following example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class MovieRecommender {
private final CustomerPreferenceDao customerPreferenceDao;
@Autowired
private MovieCatalog movieCatalog;
@Autowired
public MovieRecommender(CustomerPreferenceDao customerPreferenceDao) {
this.customerPreferenceDao = customerPreferenceDao;
}
// ...
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class MovieRecommender @Autowired constructor(
private val customerPreferenceDao: CustomerPreferenceDao) {
@Autowired
private lateinit var movieCatalog: MovieCatalog
// ...
}
----
======
[TIP]
====
Make sure that your target components (for example, `MovieCatalog` or `CustomerPreferenceDao`)
are consistently declared by the type that you use for your `@Autowired`-annotated
injection points. Otherwise, injection may fail due to a "no type match found" error at runtime.
For XML-defined beans or component classes found via classpath scanning, the container
usually knows the concrete type up front. However, for `@Bean` factory methods, you need
to make sure that the declared return type is sufficiently expressive. For components
that implement several interfaces or for components potentially referred to by their
implementation type, consider declaring the most specific return type on your factory
method (at least as specific as required by the injection points referring to your bean).
====
You can also instruct Spring to provide all beans of a particular type from the
`ApplicationContext` by adding the `@Autowired` annotation to a field or method that
expects an array of that type, as the following example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class MovieRecommender {
@Autowired
private MovieCatalog[] movieCatalogs;
// ...
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class MovieRecommender {
@Autowired
private lateinit var movieCatalogs: Array<MovieCatalog>
// ...
}
----
======
The same applies for typed collections, as the following example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class MovieRecommender {
private Set<MovieCatalog> movieCatalogs;
@Autowired
public void setMovieCatalogs(Set<MovieCatalog> movieCatalogs) {
this.movieCatalogs = movieCatalogs;
}
// ...
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class MovieRecommender {
@Autowired
lateinit var movieCatalogs: Set<MovieCatalog>
// ...
}
----
======
[[beans-factory-ordered]]
[TIP]
====
Your target beans can implement the `org.springframework.core.Ordered` interface or use
the `@Order` or standard `@Priority` annotation if you want items in the array or list
to be sorted in a specific order. Otherwise, their order follows the registration
order of the corresponding target bean definitions in the container.
You can declare the `@Order` annotation at the target class level and on `@Bean` methods,
potentially for individual bean definitions (in case of multiple definitions that
use the same bean class). `@Order` values may influence priorities at injection points,
but be aware that they do not influence singleton startup order, which is an
orthogonal concern determined by dependency relationships and `@DependsOn` declarations.
Note that the standard `jakarta.annotation.Priority` annotation is not available at the
`@Bean` level, since it cannot be declared on methods. Its semantics can be modeled
through `@Order` values in combination with `@Primary` on a single bean for each type.
====
Even typed `Map` instances can be autowired as long as the expected key type is `String`.
The map values contain all beans of the expected type, and the keys contain the
corresponding bean names, as the following example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class MovieRecommender {
private Map<String, MovieCatalog> movieCatalogs;
@Autowired
public void setMovieCatalogs(Map<String, MovieCatalog> movieCatalogs) {
this.movieCatalogs = movieCatalogs;
}
// ...
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class MovieRecommender {
@Autowired
lateinit var movieCatalogs: Map<String, MovieCatalog>
// ...
}
----
======
By default, autowiring fails when no matching candidate beans are available for a given
injection point. In the case of a declared array, collection, or map, at least one
matching element is expected.
The default behavior is to treat annotated methods and fields as indicating required
dependencies. You can change this behavior as demonstrated in the following example,
enabling the framework to skip a non-satisfiable injection point through marking it as
non-required (i.e., by setting the `required` attribute in `@Autowired` to `false`):
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class SimpleMovieLister {
private MovieFinder movieFinder;
@Autowired(required = false)
public void setMovieFinder(MovieFinder movieFinder) {
this.movieFinder = movieFinder;
}
// ...
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class SimpleMovieLister {
@Autowired(required = false)
var movieFinder: MovieFinder? = null
// ...
}
----
======
[NOTE]
====
A non-required method will not be called at all if its dependency (or one of its
dependencies, in case of multiple arguments) is not available. A non-required field will
not get populated at all in such cases, leaving its default value in place.
In other words, setting the `required` attribute to `false` indicates that the
corresponding property is _optional_ for autowiring purposes, and the property will be
ignored if it cannot be autowired. This allows properties to be assigned default values
that can be optionally overridden via dependency injection.
====
[[beans-autowired-annotation-constructor-resolution]]
Injected constructor and factory method arguments are a special case since the `required`
attribute in `@Autowired` has a somewhat different meaning due to Spring's constructor
resolution algorithm that may potentially deal with multiple constructors. Constructor
and factory method arguments are effectively required by default but with a few special
rules in a single-constructor scenario, such as multi-element injection points (arrays,
collections, maps) resolving to empty instances if no matching beans are available. This
allows for a common implementation pattern where all dependencies can be declared in a
unique multi-argument constructor — for example, declared as a single public constructor
without an `@Autowired` annotation.
[NOTE]
====
Only one constructor of any given bean class may declare `@Autowired` with the `required`
attribute set to `true`, indicating _the_ constructor to autowire when used as a Spring
bean. As a consequence, if the `required` attribute is left at its default value `true`,
only a single constructor may be annotated with `@Autowired`. If multiple constructors
declare the annotation, they will all have to declare `required=false` in order to be
considered as candidates for autowiring (analogous to `autowire=constructor` in XML).
The constructor with the greatest number of dependencies that can be satisfied by matching
beans in the Spring container will be chosen. If none of the candidates can be satisfied,
then a primary/default constructor (if present) will be used. Similarly, if a class
declares multiple constructors but none of them is annotated with `@Autowired`, then a
primary/default constructor (if present) will be used. If a class only declares a single
constructor to begin with, it will always be used, even if not annotated. Note that an
annotated constructor does not have to be public.
====
Alternatively, you can express the non-required nature of a particular dependency
through Java 8's `java.util.Optional`, as the following example shows:
[source,java,indent=0,subs="verbatim,quotes"]
----
public class SimpleMovieLister {
@Autowired
public void setMovieFinder(Optional<MovieFinder> movieFinder) {
...
}
}
----
As of Spring Framework 5.0, you can also use a `@Nullable` annotation (of any kind
in any package -- for example, `javax.annotation.Nullable` from JSR-305) or just leverage
Kotlin built-in null-safety support:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class SimpleMovieLister {
@Autowired
public void setMovieFinder(@Nullable MovieFinder movieFinder) {
...
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class SimpleMovieLister {
@Autowired
var movieFinder: MovieFinder? = null
// ...
}
----
======
You can also use `@Autowired` for interfaces that are well-known resolvable
dependencies: `BeanFactory`, `ApplicationContext`, `Environment`, `ResourceLoader`,
`ApplicationEventPublisher`, and `MessageSource`. These interfaces and their extended
interfaces, such as `ConfigurableApplicationContext` or `ResourcePatternResolver`, are
automatically resolved, with no special setup necessary. The following example autowires
an `ApplicationContext` object:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class MovieRecommender {
@Autowired
private ApplicationContext context;
public MovieRecommender() {
}
// ...
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class MovieRecommender {
@Autowired
lateinit var context: ApplicationContext
// ...
}
----
======
[NOTE]
====
The `@Autowired`, `@Inject`, `@Value`, and `@Resource` annotations are handled by Spring
`BeanPostProcessor` implementations. This means that you cannot apply these annotations
within your own `BeanPostProcessor` or `BeanFactoryPostProcessor` types (if any).
These types must be 'wired up' explicitly by using XML or a Spring `@Bean` method.
====
@@ -1,33 +0,0 @@
[[beans-custom-autowire-configurer]]
= Using `CustomAutowireConfigurer`
{spring-framework-api}/beans/factory/annotation/CustomAutowireConfigurer.html[`CustomAutowireConfigurer`]
is a `BeanFactoryPostProcessor` that lets you register your own custom qualifier
annotation types, even if they are not annotated with Spring's `@Qualifier` annotation.
The following example shows how to use `CustomAutowireConfigurer`:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean id="customAutowireConfigurer"
class="org.springframework.beans.factory.annotation.CustomAutowireConfigurer">
<property name="customQualifierTypes">
<set>
<value>example.CustomQualifier</value>
</set>
</property>
</bean>
----
The `AutowireCandidateResolver` determines autowire candidates by:
* The `autowire-candidate` value of each bean definition
* Any `default-autowire-candidates` patterns available on the `<beans/>` element
* The presence of `@Qualifier` annotations and any custom annotations registered
with the `CustomAutowireConfigurer`
When multiple beans qualify as autowire candidates, the determination of a "`primary`" is
as follows: If exactly one bean definition among the candidates has a `primary`
attribute set to `true`, it is selected.
@@ -1,101 +0,0 @@
[[beans-generics-as-qualifiers]]
= Using Generics as Autowiring Qualifiers
In addition to the `@Qualifier` annotation, you can use Java generic types
as an implicit form of qualification. For example, suppose you have the following
configuration:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
@Configuration
public class MyConfiguration {
@Bean
public StringStore stringStore() {
return new StringStore();
}
@Bean
public IntegerStore integerStore() {
return new IntegerStore();
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
@Configuration
class MyConfiguration {
@Bean
fun stringStore() = StringStore()
@Bean
fun integerStore() = IntegerStore()
}
----
======
Assuming that the preceding beans implement a generic interface, (that is, `Store<String>` and
`Store<Integer>`), you can `@Autowire` the `Store` interface and the generic is
used as a qualifier, as the following example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
@Autowired
private Store<String> s1; // <String> qualifier, injects the stringStore bean
@Autowired
private Store<Integer> s2; // <Integer> qualifier, injects the integerStore bean
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
@Autowired
private lateinit var s1: Store<String> // <String> qualifier, injects the stringStore bean
@Autowired
private lateinit var s2: Store<Integer> // <Integer> qualifier, injects the integerStore bean
----
======
Generic qualifiers also apply when autowiring lists, `Map` instances and arrays. The
following example autowires a generic `List`:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
// Inject all Store beans as long as they have an <Integer> generic
// Store<String> beans will not appear in this list
@Autowired
private List<Store<Integer>> s;
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
// Inject all Store beans as long as they have an <Integer> generic
// Store<String> beans will not appear in this list
@Autowired
private lateinit var s: List<Store<Integer>>
----
======
@@ -1,70 +0,0 @@
[[beans-postconstruct-and-predestroy-annotations]]
= Using `@PostConstruct` and `@PreDestroy`
The `CommonAnnotationBeanPostProcessor` not only recognizes the `@Resource` annotation
but also the JSR-250 lifecycle annotations: `jakarta.annotation.PostConstruct` and
`jakarta.annotation.PreDestroy`. Introduced in Spring 2.5, the support for these
annotations offers an alternative to the lifecycle callback mechanism described in
xref:core/beans/factory-nature.adoc#beans-factory-lifecycle-initializingbean[initialization callbacks] and
xref:core/beans/factory-nature.adoc#beans-factory-lifecycle-disposablebean[destruction callbacks]. Provided that the
`CommonAnnotationBeanPostProcessor` is registered within the Spring `ApplicationContext`,
a method carrying one of these annotations is invoked at the same point in the lifecycle
as the corresponding Spring lifecycle interface method or explicitly declared callback
method. In the following example, the cache is pre-populated upon initialization and
cleared upon destruction:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class CachingMovieLister {
@PostConstruct
public void populateMovieCache() {
// populates the movie cache upon initialization...
}
@PreDestroy
public void clearMovieCache() {
// clears the movie cache upon destruction...
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class CachingMovieLister {
@PostConstruct
fun populateMovieCache() {
// populates the movie cache upon initialization...
}
@PreDestroy
fun clearMovieCache() {
// clears the movie cache upon destruction...
}
}
----
======
For details about the effects of combining various lifecycle mechanisms, see
xref:core/beans/factory-nature.adoc#beans-factory-lifecycle-combined-effects[Combining Lifecycle Mechanisms].
[NOTE]
====
Like `@Resource`, the `@PostConstruct` and `@PreDestroy` annotation types were a part
of the standard Java libraries from JDK 6 to 8. However, the entire `javax.annotation`
package got separated from the core Java modules in JDK 9 and eventually removed in
JDK 11. As of Jakarta EE 9, the package lives in `jakarta.annotation` now. If needed,
the `jakarta.annotation-api` artifact needs to be obtained via Maven Central now,
simply to be added to the application's classpath like any other library.
====
@@ -1,145 +0,0 @@
[[beans-resource-annotation]]
= Injection with `@Resource`
Spring also supports injection by using the JSR-250 `@Resource` annotation
(`jakarta.annotation.Resource`) on fields or bean property setter methods.
This is a common pattern in Jakarta EE: for example, in JSF-managed beans and JAX-WS
endpoints. Spring supports this pattern for Spring-managed objects as well.
`@Resource` takes a name attribute. By default, Spring interprets that value as
the bean name to be injected. In other words, it follows by-name semantics,
as demonstrated in the following example:
--
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class SimpleMovieLister {
private MovieFinder movieFinder;
@Resource(name="myMovieFinder") // <1>
public void setMovieFinder(MovieFinder movieFinder) {
this.movieFinder = movieFinder;
}
}
----
<1> This line injects a `@Resource`.
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class SimpleMovieLister {
@Resource(name="myMovieFinder") // <1>
private lateinit var movieFinder:MovieFinder
}
----
<1> This line injects a `@Resource`.
======
--
If no name is explicitly specified, the default name is derived from the field name or
setter method. In case of a field, it takes the field name. In case of a setter method,
it takes the bean property name. The following example is going to have the bean
named `movieFinder` injected into its setter method:
--
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class SimpleMovieLister {
private MovieFinder movieFinder;
@Resource
public void setMovieFinder(MovieFinder movieFinder) {
this.movieFinder = movieFinder;
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class SimpleMovieLister {
@set:Resource
private lateinit var movieFinder: MovieFinder
}
----
======
--
NOTE: The name provided with the annotation is resolved as a bean name by the
`ApplicationContext` of which the `CommonAnnotationBeanPostProcessor` is aware.
The names can be resolved through JNDI if you configure Spring's
{spring-framework-api}/jndi/support/SimpleJndiBeanFactory.html[`SimpleJndiBeanFactory`]
explicitly. However, we recommend that you rely on the default behavior and
use Spring's JNDI lookup capabilities to preserve the level of indirection.
In the exclusive case of `@Resource` usage with no explicit name specified, and similar
to `@Autowired`, `@Resource` finds a primary type match instead of a specific named bean
and resolves well known resolvable dependencies: the `BeanFactory`,
`ApplicationContext`, `ResourceLoader`, `ApplicationEventPublisher`, and `MessageSource`
interfaces.
Thus, in the following example, the `customerPreferenceDao` field first looks for a bean
named "customerPreferenceDao" and then falls back to a primary type match for the type
`CustomerPreferenceDao`:
--
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class MovieRecommender {
@Resource
private CustomerPreferenceDao customerPreferenceDao;
@Resource
private ApplicationContext context; // <1>
public MovieRecommender() {
}
// ...
}
----
<1> The `context` field is injected based on the known resolvable dependency type:
`ApplicationContext`.
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class MovieRecommender {
@Resource
private lateinit var customerPreferenceDao: CustomerPreferenceDao
@Resource
private lateinit var context: ApplicationContext // <1>
// ...
}
----
<1> The `context` field is injected based on the known resolvable dependency type:
`ApplicationContext`.
======
--
@@ -1,242 +0,0 @@
[[beans-value-annotations]]
= Using `@Value`
`@Value` is typically used to inject externalized properties:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
@Component
public class MovieRecommender {
private final String catalog;
public MovieRecommender(@Value("${catalog.name}") String catalog) {
this.catalog = catalog;
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
@Component
class MovieRecommender(@Value("\${catalog.name}") private val catalog: String)
----
======
With the following configuration:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
@Configuration
@PropertySource("classpath:application.properties")
public class AppConfig { }
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
@Configuration
@PropertySource("classpath:application.properties")
class AppConfig
----
======
And the following `application.properties` file:
[source,java,indent=0,subs="verbatim,quotes"]
----
catalog.name=MovieCatalog
----
In that case, the `catalog` parameter and field will be equal to the `MovieCatalog` value.
A default lenient embedded value resolver is provided by Spring. It will try to resolve the
property value and if it cannot be resolved, the property name (for example `${catalog.name}`)
will be injected as the value. If you want to maintain strict control over nonexistent
values, you should declare a `PropertySourcesPlaceholderConfigurer` bean, as the following
example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
@Configuration
public class AppConfig {
@Bean
public static PropertySourcesPlaceholderConfigurer propertyPlaceholderConfigurer() {
return new PropertySourcesPlaceholderConfigurer();
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
@Configuration
class AppConfig {
@Bean
fun propertyPlaceholderConfigurer() = PropertySourcesPlaceholderConfigurer()
}
----
======
NOTE: When configuring a `PropertySourcesPlaceholderConfigurer` using JavaConfig, the
`@Bean` method must be `static`.
Using the above configuration ensures Spring initialization failure if any `${}`
placeholder could not be resolved. It is also possible to use methods like
`setPlaceholderPrefix`, `setPlaceholderSuffix`, or `setValueSeparator` to customize
placeholders.
NOTE: Spring Boot configures by default a `PropertySourcesPlaceholderConfigurer` bean that
will get properties from `application.properties` and `application.yml` files.
Built-in converter support provided by Spring allows simple type conversion (to `Integer`
or `int` for example) to be automatically handled. Multiple comma-separated values can be
automatically converted to `String` array without extra effort.
It is possible to provide a default value as following:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
@Component
public class MovieRecommender {
private final String catalog;
public MovieRecommender(@Value("${catalog.name:defaultCatalog}") String catalog) {
this.catalog = catalog;
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
@Component
class MovieRecommender(@Value("\${catalog.name:defaultCatalog}") private val catalog: String)
----
======
A Spring `BeanPostProcessor` uses a `ConversionService` behind the scenes to handle the
process for converting the `String` value in `@Value` to the target type. If you want to
provide conversion support for your own custom type, you can provide your own
`ConversionService` bean instance as the following example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
@Configuration
public class AppConfig {
@Bean
public ConversionService conversionService() {
DefaultFormattingConversionService conversionService = new DefaultFormattingConversionService();
conversionService.addConverter(new MyCustomConverter());
return conversionService;
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
@Configuration
class AppConfig {
@Bean
fun conversionService(): ConversionService {
return DefaultFormattingConversionService().apply {
addConverter(MyCustomConverter())
}
}
}
----
======
When `@Value` contains a xref:core/expressions.adoc[`SpEL` expression] the value will be dynamically
computed at runtime as the following example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
@Component
public class MovieRecommender {
private final String catalog;
public MovieRecommender(@Value("#{systemProperties['user.catalog'] + 'Catalog' }") String catalog) {
this.catalog = catalog;
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
@Component
class MovieRecommender(
@Value("#{systemProperties['user.catalog'] + 'Catalog' }") private val catalog: String)
----
======
SpEL also enables the use of more complex data structures:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
@Component
public class MovieRecommender {
private final Map<String, Integer> countOfMoviesPerCatalog;
public MovieRecommender(
@Value("#{{'Thriller': 100, 'Comedy': 300}}") Map<String, Integer> countOfMoviesPerCatalog) {
this.countOfMoviesPerCatalog = countOfMoviesPerCatalog;
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
@Component
class MovieRecommender(
@Value("#{{'Thriller': 100, 'Comedy': 300}}") private val countOfMoviesPerCatalog: Map<String, Int>)
----
======
@@ -1,423 +0,0 @@
[[beans-basics]]
= Container Overview
The `org.springframework.context.ApplicationContext` interface represents the Spring IoC
container and is responsible for instantiating, configuring, and assembling the
beans. The container gets its instructions on what objects to
instantiate, configure, and assemble by reading configuration metadata. The
configuration metadata is represented in XML, Java annotations, or Java code. It lets
you express the objects that compose your application and the rich interdependencies
between those objects.
Several implementations of the `ApplicationContext` interface are supplied
with Spring. In stand-alone applications, it is common to create an
instance of
{spring-framework-api}/context/support/ClassPathXmlApplicationContext.html[`ClassPathXmlApplicationContext`]
or {spring-framework-api}/context/support/FileSystemXmlApplicationContext.html[`FileSystemXmlApplicationContext`].
While XML has been the traditional format for defining configuration metadata, you can
instruct the container to use Java annotations or code as the metadata format by
providing a small amount of XML configuration to declaratively enable support for these
additional metadata formats.
In most application scenarios, explicit user code is not required to instantiate one or
more instances of a Spring IoC container. For example, in a web application scenario, a
simple eight (or so) lines of boilerplate web descriptor XML in the `web.xml` file
of the application typically suffices (see
xref:core/beans/context-introduction.adoc#context-create[Convenient ApplicationContext Instantiation for Web Applications]).
If you use the {spring-site-tools}[Spring Tools for Eclipse] (an Eclipse-powered
development environment), you can easily create this boilerplate configuration with a
few mouse clicks or keystrokes.
The following diagram shows a high-level view of how Spring works. Your application classes
are combined with configuration metadata so that, after the `ApplicationContext` is
created and initialized, you have a fully configured and executable system or
application.
.The Spring IoC container
image::container-magic.png[]
[[beans-factory-metadata]]
== Configuration Metadata
As the preceding diagram shows, the Spring IoC container consumes a form of
configuration metadata. This configuration metadata represents how you, as an
application developer, tell the Spring container to instantiate, configure, and assemble
the objects in your application.
Configuration metadata is traditionally supplied in a simple and intuitive XML format,
which is what most of this chapter uses to convey key concepts and features of the
Spring IoC container.
NOTE: XML-based metadata is not the only allowed form of configuration metadata.
The Spring IoC container itself is totally decoupled from the format in which this
configuration metadata is actually written. These days, many developers choose
xref:core/beans/java.adoc[Java-based configuration] for their Spring applications.
For information about using other forms of metadata with the Spring container, see:
* xref:core/beans/annotation-config.adoc[Annotation-based configuration]: define beans using
annotation-based configuration metadata.
* xref:core/beans/java.adoc[Java-based configuration]: define beans external to your application
classes by using Java rather than XML files. To use these features, see the
{spring-framework-api}/context/annotation/Configuration.html[`@Configuration`],
{spring-framework-api}/context/annotation/Bean.html[`@Bean`],
{spring-framework-api}/context/annotation/Import.html[`@Import`],
and {spring-framework-api}/context/annotation/DependsOn.html[`@DependsOn`] annotations.
Spring configuration consists of at least one and typically more than one bean
definition that the container must manage. XML-based configuration metadata configures these
beans as `<bean/>` elements inside a top-level `<beans/>` element. Java
configuration typically uses `@Bean`-annotated methods within a `@Configuration` class.
These bean definitions correspond to the actual objects that make up your application.
Typically, you define service layer objects, persistence layer objects such as
repositories or data access objects (DAOs), presentation objects such as Web controllers,
infrastructure objects such as a JPA `EntityManagerFactory`, JMS queues, and so forth.
Typically, one does not configure fine-grained domain objects in the container, because
it is usually the responsibility of repositories and business logic to create and load
domain objects.
The following example shows the basic structure of XML-based configuration metadata:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd">
<bean id="..." class="..."> <1> <2>
<!-- collaborators and configuration for this bean go here -->
</bean>
<bean id="..." class="...">
<!-- collaborators and configuration for this bean go here -->
</bean>
<!-- more bean definitions go here -->
</beans>
----
<1> The `id` attribute is a string that identifies the individual bean definition.
<2> The `class` attribute defines the type of the bean and uses the fully qualified
class name.
The value of the `id` attribute can be used to refer to collaborating objects. The XML
for referring to collaborating objects is not shown in this example. See
xref:core/beans/dependencies.adoc[Dependencies] for more information.
[[beans-factory-instantiation]]
== Instantiating a Container
The location path or paths
supplied to an `ApplicationContext` constructor are resource strings that let
the container load configuration metadata from a variety of external resources, such
as the local file system, the Java `CLASSPATH`, and so on.
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
ApplicationContext context = new ClassPathXmlApplicationContext("services.xml", "daos.xml");
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
val context = ClassPathXmlApplicationContext("services.xml", "daos.xml")
----
======
[NOTE]
====
After you learn about Spring's IoC container, you may want to know more about Spring's
`Resource` abstraction (as described in
xref:web/webflux-webclient/client-builder.adoc#webflux-client-builder-reactor-resources[Resources])
which provides a convenient mechanism for reading an InputStream from locations defined
in a URI syntax. In particular, `Resource` paths are used to construct applications contexts,
as described in xref:core/resources.adoc#resources-app-ctx[Application Contexts and Resource Paths].
====
The following example shows the service layer objects `(services.xml)` configuration file:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd">
<!-- services -->
<bean id="petStore" class="org.springframework.samples.jpetstore.services.PetStoreServiceImpl">
<property name="accountDao" ref="accountDao"/>
<property name="itemDao" ref="itemDao"/>
<!-- additional collaborators and configuration for this bean go here -->
</bean>
<!-- more bean definitions for services go here -->
</beans>
----
The following example shows the data access objects `daos.xml` file:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd">
<bean id="accountDao"
class="org.springframework.samples.jpetstore.dao.jpa.JpaAccountDao">
<!-- additional collaborators and configuration for this bean go here -->
</bean>
<bean id="itemDao" class="org.springframework.samples.jpetstore.dao.jpa.JpaItemDao">
<!-- additional collaborators and configuration for this bean go here -->
</bean>
<!-- more bean definitions for data access objects go here -->
</beans>
----
In the preceding example, the service layer consists of the `PetStoreServiceImpl` class
and two data access objects of the types `JpaAccountDao` and `JpaItemDao` (based
on the JPA Object-Relational Mapping standard). The `property name` element refers to the
name of the JavaBean property, and the `ref` element refers to the name of another bean
definition. This linkage between `id` and `ref` elements expresses the dependency between
collaborating objects. For details of configuring an object's dependencies, see
xref:core/beans/dependencies.adoc[Dependencies].
[[beans-factory-xml-import]]
=== Composing XML-based Configuration Metadata
It can be useful to have bean definitions span multiple XML files. Often, each individual
XML configuration file represents a logical layer or module in your architecture.
You can use the application context constructor to load bean definitions from all these
XML fragments. This constructor takes multiple `Resource` locations, as was shown in the
xref:core/beans/basics.adoc#beans-factory-instantiation[previous section]. Alternatively,
use one or more occurrences of the `<import/>` element to load bean definitions from
another file or files. The following example shows how to do so:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<beans>
<import resource="services.xml"/>
<import resource="resources/messageSource.xml"/>
<import resource="/resources/themeSource.xml"/>
<bean id="bean1" class="..."/>
<bean id="bean2" class="..."/>
</beans>
----
In the preceding example, external bean definitions are loaded from three files:
`services.xml`, `messageSource.xml`, and `themeSource.xml`. All location paths are
relative to the definition file doing the importing, so `services.xml` must be in the
same directory or classpath location as the file doing the importing, while
`messageSource.xml` and `themeSource.xml` must be in a `resources` location below the
location of the importing file. As you can see, a leading slash is ignored. However, given
that these paths are relative, it is better form not to use the slash at all. The
contents of the files being imported, including the top level `<beans/>` element, must
be valid XML bean definitions, according to the Spring Schema.
[NOTE]
====
It is possible, but not recommended, to reference files in parent directories using a
relative "../" path. Doing so creates a dependency on a file that is outside the current
application. In particular, this reference is not recommended for `classpath:` URLs (for
example, `classpath:../services.xml`), where the runtime resolution process chooses the
"`nearest`" classpath root and then looks into its parent directory. Classpath
configuration changes may lead to the choice of a different, incorrect directory.
You can always use fully qualified resource locations instead of relative paths: for
example, `file:C:/config/services.xml` or `classpath:/config/services.xml`. However, be
aware that you are coupling your application's configuration to specific absolute
locations. It is generally preferable to keep an indirection for such absolute
locations -- for example, through "${...}" placeholders that are resolved against JVM
system properties at runtime.
====
The namespace itself provides the import directive feature. Further
configuration features beyond plain bean definitions are available in a selection
of XML namespaces provided by Spring -- for example, the `context` and `util` namespaces.
[[groovy-bean-definition-dsl]]
=== The Groovy Bean Definition DSL
As a further example for externalized configuration metadata, bean definitions can also
be expressed in Spring's Groovy Bean Definition DSL, as known from the Grails framework.
Typically, such configuration live in a ".groovy" file with the structure shown in the
following example:
[source,groovy,indent=0,subs="verbatim,quotes"]
----
beans {
dataSource(BasicDataSource) {
driverClassName = "org.hsqldb.jdbcDriver"
url = "jdbc:hsqldb:mem:grailsDB"
username = "sa"
password = ""
settings = [mynew:"setting"]
}
sessionFactory(SessionFactory) {
dataSource = dataSource
}
myService(MyService) {
nestedBean = { AnotherBean bean ->
dataSource = dataSource
}
}
}
----
This configuration style is largely equivalent to XML bean definitions and even
supports Spring's XML configuration namespaces. It also allows for importing XML
bean definition files through an `importBeans` directive.
[[beans-factory-client]]
== Using the Container
The `ApplicationContext` is the interface for an advanced factory capable of maintaining
a registry of different beans and their dependencies. By using the method
`T getBean(String name, Class<T> requiredType)`, you can retrieve instances of your beans.
The `ApplicationContext` lets you read bean definitions and access them, as the following
example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
// create and configure beans
ApplicationContext context = new ClassPathXmlApplicationContext("services.xml", "daos.xml");
// retrieve configured instance
PetStoreService service = context.getBean("petStore", PetStoreService.class);
// use configured instance
List<String> userList = service.getUsernameList();
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
import org.springframework.beans.factory.getBean
// create and configure beans
val context = ClassPathXmlApplicationContext("services.xml", "daos.xml")
// retrieve configured instance
val service = context.getBean<PetStoreService>("petStore")
// use configured instance
var userList = service.getUsernameList()
----
======
With Groovy configuration, bootstrapping looks very similar. It has a different context
implementation class which is Groovy-aware (but also understands XML bean definitions).
The following example shows Groovy configuration:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
ApplicationContext context = new GenericGroovyApplicationContext("services.groovy", "daos.groovy");
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
val context = GenericGroovyApplicationContext("services.groovy", "daos.groovy")
----
======
The most flexible variant is `GenericApplicationContext` in combination with reader
delegates -- for example, with `XmlBeanDefinitionReader` for XML files, as the following
example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
GenericApplicationContext context = new GenericApplicationContext();
new XmlBeanDefinitionReader(context).loadBeanDefinitions("services.xml", "daos.xml");
context.refresh();
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
val context = GenericApplicationContext()
XmlBeanDefinitionReader(context).loadBeanDefinitions("services.xml", "daos.xml")
context.refresh()
----
======
You can also use the `GroovyBeanDefinitionReader` for Groovy files, as the following
example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
GenericApplicationContext context = new GenericApplicationContext();
new GroovyBeanDefinitionReader(context).loadBeanDefinitions("services.groovy", "daos.groovy");
context.refresh();
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
val context = GenericApplicationContext()
GroovyBeanDefinitionReader(context).loadBeanDefinitions("services.groovy", "daos.groovy")
context.refresh()
----
======
You can mix and match such reader delegates on the same `ApplicationContext`,
reading bean definitions from diverse configuration sources.
You can then use `getBean` to retrieve instances of your beans. The `ApplicationContext`
interface has a few other methods for retrieving beans, but, ideally, your application
code should never use them. Indeed, your application code should have no calls to the
`getBean()` method at all and thus have no dependency on Spring APIs at all. For example,
Spring's integration with web frameworks provides dependency injection for various web
framework components such as controllers and JSF-managed beans, letting you declare
a dependency on a specific bean through metadata (such as an autowiring annotation).
@@ -1,171 +0,0 @@
[[beans-beanfactory]]
= The `BeanFactory` API
The `BeanFactory` API provides the underlying basis for Spring's IoC functionality.
Its specific contracts are mostly used in integration with other parts of Spring and
related third-party frameworks, and its `DefaultListableBeanFactory` implementation
is a key delegate within the higher-level `GenericApplicationContext` container.
`BeanFactory` and related interfaces (such as `BeanFactoryAware`, `InitializingBean`,
`DisposableBean`) are important integration points for other framework components.
By not requiring any annotations or even reflection, they allow for very efficient
interaction between the container and its components. Application-level beans may
use the same callback interfaces but typically prefer declarative dependency
injection instead, either through annotations or through programmatic configuration.
Note that the core `BeanFactory` API level and its `DefaultListableBeanFactory`
implementation do not make assumptions about the configuration format or any
component annotations to be used. All of these flavors come in through extensions
(such as `XmlBeanDefinitionReader` and `AutowiredAnnotationBeanPostProcessor`) and
operate on shared `BeanDefinition` objects as a core metadata representation.
This is the essence of what makes Spring's container so flexible and extensible.
[[context-introduction-ctx-vs-beanfactory]]
== `BeanFactory` or `ApplicationContext`?
This section explains the differences between the `BeanFactory` and
`ApplicationContext` container levels and the implications on bootstrapping.
You should use an `ApplicationContext` unless you have a good reason for not doing so, with
`GenericApplicationContext` and its subclass `AnnotationConfigApplicationContext`
as the common implementations for custom bootstrapping. These are the primary entry
points to Spring's core container for all common purposes: loading of configuration
files, triggering a classpath scan, programmatically registering bean definitions
and annotated classes, and (as of 5.0) registering functional bean definitions.
Because an `ApplicationContext` includes all the functionality of a `BeanFactory`, it is
generally recommended over a plain `BeanFactory`, except for scenarios where full
control over bean processing is needed. Within an `ApplicationContext` (such as the
`GenericApplicationContext` implementation), several kinds of beans are detected
by convention (that is, by bean name or by bean type -- in particular, post-processors),
while a plain `DefaultListableBeanFactory` is agnostic about any special beans.
For many extended container features, such as annotation processing and AOP proxying,
the xref:core/beans/factory-extension.adoc#beans-factory-extension-bpp[`BeanPostProcessor` extension point] is essential.
If you use only a plain `DefaultListableBeanFactory`, such post-processors do not
get detected and activated by default. This situation could be confusing, because
nothing is actually wrong with your bean configuration. Rather, in such a scenario,
the container needs to be fully bootstrapped through additional setup.
The following table lists features provided by the `BeanFactory` and
`ApplicationContext` interfaces and implementations.
[[context-introduction-ctx-vs-beanfactory-feature-matrix]]
.Feature Matrix
[cols="50%,25%,25%"]
|===
| Feature | `BeanFactory` | `ApplicationContext`
| Bean instantiation/wiring
| Yes
| Yes
| Integrated lifecycle management
| No
| Yes
| Automatic `BeanPostProcessor` registration
| No
| Yes
| Automatic `BeanFactoryPostProcessor` registration
| No
| Yes
| Convenient `MessageSource` access (for internationalization)
| No
| Yes
| Built-in `ApplicationEvent` publication mechanism
| No
| Yes
|===
To explicitly register a bean post-processor with a `DefaultListableBeanFactory`,
you need to programmatically call `addBeanPostProcessor`, as the following example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
DefaultListableBeanFactory factory = new DefaultListableBeanFactory();
// populate the factory with bean definitions
// now register any needed BeanPostProcessor instances
factory.addBeanPostProcessor(new AutowiredAnnotationBeanPostProcessor());
factory.addBeanPostProcessor(new MyBeanPostProcessor());
// now start using the factory
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
val factory = DefaultListableBeanFactory()
// populate the factory with bean definitions
// now register any needed BeanPostProcessor instances
factory.addBeanPostProcessor(AutowiredAnnotationBeanPostProcessor())
factory.addBeanPostProcessor(MyBeanPostProcessor())
// now start using the factory
----
======
To apply a `BeanFactoryPostProcessor` to a plain `DefaultListableBeanFactory`,
you need to call its `postProcessBeanFactory` method, as the following example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
DefaultListableBeanFactory factory = new DefaultListableBeanFactory();
XmlBeanDefinitionReader reader = new XmlBeanDefinitionReader(factory);
reader.loadBeanDefinitions(new FileSystemResource("beans.xml"));
// bring in some property values from a Properties file
PropertySourcesPlaceholderConfigurer cfg = new PropertySourcesPlaceholderConfigurer();
cfg.setLocation(new FileSystemResource("jdbc.properties"));
// now actually do the replacement
cfg.postProcessBeanFactory(factory);
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
val factory = DefaultListableBeanFactory()
val reader = XmlBeanDefinitionReader(factory)
reader.loadBeanDefinitions(FileSystemResource("beans.xml"))
// bring in some property values from a Properties file
val cfg = PropertySourcesPlaceholderConfigurer()
cfg.setLocation(FileSystemResource("jdbc.properties"))
// now actually do the replacement
cfg.postProcessBeanFactory(factory)
----
======
In both cases, the explicit registration steps are inconvenient, which is
why the various `ApplicationContext` variants are preferred over a plain
`DefaultListableBeanFactory` in Spring-backed applications, especially when
relying on `BeanFactoryPostProcessor` and `BeanPostProcessor` instances for extended
container functionality in a typical enterprise setup.
[NOTE]
====
An `AnnotationConfigApplicationContext` has all common annotation post-processors
registered and may bring in additional processors underneath the
covers through configuration annotations, such as `@EnableTransactionManagement`.
At the abstraction level of Spring's annotation-based configuration model,
the notion of bean post-processors becomes a mere internal container detail.
====
@@ -1,84 +0,0 @@
[[beans-child-bean-definitions]]
= Bean Definition Inheritance
A bean definition can contain a lot of configuration information, including constructor
arguments, property values, and container-specific information, such as the initialization
method, a static factory method name, and so on. A child bean definition inherits
configuration data from a parent definition. The child definition can override some
values or add others as needed. Using parent and child bean definitions can save a lot
of typing. Effectively, this is a form of templating.
If you work with an `ApplicationContext` interface programmatically, child bean
definitions are represented by the `ChildBeanDefinition` class. Most users do not work
with them on this level. Instead, they configure bean definitions declaratively in a class
such as the `ClassPathXmlApplicationContext`. When you use XML-based configuration
metadata, you can indicate a child bean definition by using the `parent` attribute,
specifying the parent bean as the value of this attribute. The following example shows how
to do so:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean id="inheritedTestBean" abstract="true"
class="org.springframework.beans.TestBean">
<property name="name" value="parent"/>
<property name="age" value="1"/>
</bean>
<bean id="inheritsWithDifferentClass"
class="org.springframework.beans.DerivedTestBean"
parent="inheritedTestBean" init-method="initialize"> <1>
<property name="name" value="override"/>
<!-- the age property value of 1 will be inherited from parent -->
</bean>
----
<1> Note the `parent` attribute.
A child bean definition uses the bean class from the parent definition if none is
specified but can also override it. In the latter case, the child bean class must be
compatible with the parent (that is, it must accept the parent's property values).
A child bean definition inherits scope, constructor argument values, property values, and
method overrides from the parent, with the option to add new values. Any scope, initialization
method, destroy method, or `static` factory method settings that you specify
override the corresponding parent settings.
The remaining settings are always taken from the child definition: depends on,
autowire mode, dependency check, singleton, and lazy init.
The preceding example explicitly marks the parent bean definition as abstract by using
the `abstract` attribute. If the parent definition does not specify a class, explicitly
marking the parent bean definition as `abstract` is required, as the following example
shows:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean id="inheritedTestBeanWithoutClass" abstract="true">
<property name="name" value="parent"/>
<property name="age" value="1"/>
</bean>
<bean id="inheritsWithClass" class="org.springframework.beans.DerivedTestBean"
parent="inheritedTestBeanWithoutClass" init-method="initialize">
<property name="name" value="override"/>
<!-- age will inherit the value of 1 from the parent bean definition-->
</bean>
----
The parent bean cannot be instantiated on its own because it is incomplete, and it is
also explicitly marked as `abstract`. When a definition is `abstract`, it is
usable only as a pure template bean definition that serves as a parent definition for
child definitions. Trying to use such an `abstract` parent bean on its own, by referring
to it as a ref property of another bean or doing an explicit `getBean()` call with the
parent bean ID returns an error. Similarly, the container's internal
`preInstantiateSingletons()` method ignores bean definitions that are defined as
abstract.
NOTE: `ApplicationContext` pre-instantiates all singletons by default. Therefore, it is
important (at least for singleton beans) that if you have a (parent) bean definition
which you intend to use only as a template, and this definition specifies a class, you
must make sure to set the __abstract__ attribute to __true__, otherwise the application
context will actually (attempt to) pre-instantiate the `abstract` bean.
File diff suppressed because it is too large Load Diff
File diff suppressed because it is too large Load Diff
@@ -1,52 +0,0 @@
[[context-load-time-weaver]]
= Registering a `LoadTimeWeaver`
The `LoadTimeWeaver` is used by Spring to dynamically transform classes as they are
loaded into the Java virtual machine (JVM).
To enable load-time weaving, you can add the `@EnableLoadTimeWeaving` to one of your
`@Configuration` classes, as the following example shows:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
@Configuration
@EnableLoadTimeWeaving
public class AppConfig {
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
@Configuration
@EnableLoadTimeWeaving
class AppConfig
----
======
Alternatively, for XML configuration, you can use the `context:load-time-weaver` element:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<beans>
<context:load-time-weaver/>
</beans>
----
Once configured for the `ApplicationContext`, any bean within that `ApplicationContext`
may implement `LoadTimeWeaverAware`, thereby receiving a reference to the load-time
weaver instance. This is particularly useful in combination with
xref:data-access/orm/jpa.adoc[Spring's JPA support] where load-time weaving may be
necessary for JPA class transformation.
Consult the
{spring-framework-api}/orm/jpa/LocalContainerEntityManagerFactoryBean.html[`LocalContainerEntityManagerFactoryBean`]
javadoc for more detail. For more on AspectJ load-time weaving, see xref:core/aop/using-aspectj.adoc#aop-aj-ltw[Load-time Weaving with AspectJ in the Spring Framework].
@@ -1,448 +0,0 @@
[[beans-definition]]
= Bean Overview
A Spring IoC container manages one or more beans. These beans are created with the
configuration metadata that you supply to the container (for example, in the form of XML
`<bean/>` definitions).
Within the container itself, these bean definitions are represented as `BeanDefinition`
objects, which contain (among other information) the following metadata:
* A package-qualified class name: typically, the actual implementation class of the
bean being defined.
* Bean behavioral configuration elements, which state how the bean should behave in the
container (scope, lifecycle callbacks, and so forth).
* References to other beans that are needed for the bean to do its work. These
references are also called collaborators or dependencies.
* Other configuration settings to set in the newly created object -- for example, the size
limit of the pool or the number of connections to use in a bean that manages a
connection pool.
This metadata translates to a set of properties that make up each bean definition.
The following table describes these properties:
[[beans-factory-bean-definition-tbl]]
.The bean definition
|===
| Property| Explained in...
| Class
| xref:core/beans/definition.adoc#beans-factory-class[Instantiating Beans]
| Name
| xref:core/beans/definition.adoc#beans-beanname[Naming Beans]
| Scope
| xref:core/beans/factory-scopes.adoc[Bean Scopes]
| Constructor arguments
| xref:core/beans/dependencies/factory-collaborators.adoc[Dependency Injection]
| Properties
| xref:core/beans/dependencies/factory-collaborators.adoc[Dependency Injection]
| Autowiring mode
| xref:core/beans/dependencies/factory-autowire.adoc[Autowiring Collaborators]
| Lazy initialization mode
| xref:core/beans/dependencies/factory-lazy-init.adoc[Lazy-initialized Beans]
| Initialization method
| xref:core/beans/factory-nature.adoc#beans-factory-lifecycle-initializingbean[Initialization Callbacks]
| Destruction method
| xref:core/beans/factory-nature.adoc#beans-factory-lifecycle-disposablebean[Destruction Callbacks]
|===
In addition to bean definitions that contain information on how to create a specific
bean, the `ApplicationContext` implementations also permit the registration of existing
objects that are created outside the container (by users). This is done by accessing the
ApplicationContext's `BeanFactory` through the `getBeanFactory()` method, which returns
the `DefaultListableBeanFactory` implementation. `DefaultListableBeanFactory` supports
this registration through the `registerSingleton(..)` and `registerBeanDefinition(..)`
methods. However, typical applications work solely with beans defined through regular
bean definition metadata.
[NOTE]
====
Bean metadata and manually supplied singleton instances need to be registered as early
as possible, in order for the container to properly reason about them during autowiring
and other introspection steps. While overriding existing metadata and existing
singleton instances is supported to some degree, the registration of new beans at
runtime (concurrently with live access to the factory) is not officially supported and may
lead to concurrent access exceptions, inconsistent state in the bean container, or both.
====
[[beans-beanname]]
== Naming Beans
Every bean has one or more identifiers. These identifiers must be unique within the
container that hosts the bean. A bean usually has only one identifier. However, if it
requires more than one, the extra ones can be considered aliases.
In XML-based configuration metadata, you use the `id` attribute, the `name` attribute, or
both to specify bean identifiers. The `id` attribute lets you specify exactly one `id`.
Conventionally, these names are alphanumeric ('myBean', 'someService', etc.), but they
can contain special characters as well. If you want to introduce other aliases for the
bean, you can also specify them in the `name` attribute, separated by a comma (`,`),
semicolon (`;`), or white space. Although the `id` attribute is defined as an
`xsd:string` type, bean `id` uniqueness is enforced by the container, though not by XML
parsers.
You are not required to supply a `name` or an `id` for a bean. If you do not supply a
`name` or `id` explicitly, the container generates a unique name for that bean. However,
if you want to refer to that bean by name, through the use of the `ref` element or a
Service Locator style lookup, you must provide a name.
Motivations for not supplying a name are related to using xref:core/beans/dependencies/factory-properties-detailed.adoc#beans-inner-beans[inner beans]
and xref:core/beans/dependencies/factory-autowire.adoc[autowiring collaborators].
.Bean Naming Conventions
****
The convention is to use the standard Java convention for instance field names when
naming beans. That is, bean names start with a lowercase letter and are camel-cased
from there. Examples of such names include `accountManager`,
`accountService`, `userDao`, `loginController`, and so forth.
Naming beans consistently makes your configuration easier to read and understand.
Also, if you use Spring AOP, it helps a lot when applying advice to a set of beans
related by name.
****
NOTE: With component scanning in the classpath, Spring generates bean names for unnamed
components, following the rules described earlier: essentially, taking the simple class name
and turning its initial character to lower-case. However, in the (unusual) special
case when there is more than one character and both the first and second characters
are upper case, the original casing gets preserved. These are the same rules as
defined by `java.beans.Introspector.decapitalize` (which Spring uses here).
[[beans-beanname-alias]]
=== Aliasing a Bean outside the Bean Definition
In a bean definition itself, you can supply more than one name for the bean, by using a
combination of up to one name specified by the `id` attribute and any number of other
names in the `name` attribute. These names can be equivalent aliases to the same bean
and are useful for some situations, such as letting each component in an application
refer to a common dependency by using a bean name that is specific to that component
itself.
Specifying all aliases where the bean is actually defined is not always adequate,
however. It is sometimes desirable to introduce an alias for a bean that is defined
elsewhere. This is commonly the case in large systems where configuration is split
amongst each subsystem, with each subsystem having its own set of object definitions.
In XML-based configuration metadata, you can use the `<alias/>` element to accomplish
this. The following example shows how to do so:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<alias name="fromName" alias="toName"/>
----
In this case, a bean (in the same container) named `fromName` may also,
after the use of this alias definition, be referred to as `toName`.
For example, the configuration metadata for subsystem A may refer to a DataSource by the
name of `subsystemA-dataSource`. The configuration metadata for subsystem B may refer to
a DataSource by the name of `subsystemB-dataSource`. When composing the main application
that uses both these subsystems, the main application refers to the DataSource by the
name of `myApp-dataSource`. To have all three names refer to the same object, you can
add the following alias definitions to the configuration metadata:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<alias name="myApp-dataSource" alias="subsystemA-dataSource"/>
<alias name="myApp-dataSource" alias="subsystemB-dataSource"/>
----
Now each component and the main application can refer to the dataSource through a name
that is unique and guaranteed not to clash with any other definition (effectively
creating a namespace), yet they refer to the same bean.
.Java-configuration
****
If you use Java Configuration, the `@Bean` annotation can be used to provide aliases.
See xref:core/beans/java/bean-annotation.adoc[Using the `@Bean` Annotation] for details.
****
[[beans-factory-class]]
== Instantiating Beans
A bean definition is essentially a recipe for creating one or more objects. The
container looks at the recipe for a named bean when asked and uses the configuration
metadata encapsulated by that bean definition to create (or acquire) an actual object.
If you use XML-based configuration metadata, you specify the type (or class) of object
that is to be instantiated in the `class` attribute of the `<bean/>` element. This
`class` attribute (which, internally, is a `Class` property on a `BeanDefinition`
instance) is usually mandatory. (For exceptions, see
xref:core/beans/definition.adoc#beans-factory-class-instance-factory-method[Instantiation by Using an Instance Factory Method] and xref:core/beans/child-bean-definitions.adoc[Bean Definition Inheritance].)
You can use the `Class` property in one of two ways:
* Typically, to specify the bean class to be constructed in the case where the container
itself directly creates the bean by calling its constructor reflectively, somewhat
equivalent to Java code with the `new` operator.
* To specify the actual class containing the `static` factory method that is
invoked to create the object, in the less common case where the container invokes a
`static` factory method on a class to create the bean. The object type returned
from the invocation of the `static` factory method may be the same class or another
class entirely.
.Nested class names
****
If you want to configure a bean definition for a nested class, you may use either the
binary name or the source name of the nested class.
For example, if you have a class called `SomeThing` in the `com.example` package, and
this `SomeThing` class has a `static` nested class called `OtherThing`, they can be
separated by a dollar sign (`$`) or a dot (`.`). So the value of the `class` attribute in
a bean definition would be `com.example.SomeThing$OtherThing` or
`com.example.SomeThing.OtherThing`.
****
[[beans-factory-class-ctor]]
=== Instantiation with a Constructor
When you create a bean by the constructor approach, all normal classes are usable by and
compatible with Spring. That is, the class being developed does not need to implement
any specific interfaces or to be coded in a specific fashion. Simply specifying the bean
class should suffice. However, depending on what type of IoC you use for that specific
bean, you may need a default (empty) constructor.
The Spring IoC container can manage virtually any class you want it to manage. It is
not limited to managing true JavaBeans. Most Spring users prefer actual JavaBeans with
only a default (no-argument) constructor and appropriate setters and getters modeled
after the properties in the container. You can also have more exotic non-bean-style
classes in your container. If, for example, you need to use a legacy connection pool
that absolutely does not adhere to the JavaBean specification, Spring can manage it as
well.
With XML-based configuration metadata you can specify your bean class as follows:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean id="exampleBean" class="examples.ExampleBean"/>
<bean name="anotherExample" class="examples.ExampleBeanTwo"/>
----
For details about the mechanism for supplying arguments to the constructor (if required)
and setting object instance properties after the object is constructed, see
xref:core/beans/dependencies/factory-collaborators.adoc[Injecting Dependencies].
[[beans-factory-class-static-factory-method]]
=== Instantiation with a Static Factory Method
When defining a bean that you create with a static factory method, use the `class`
attribute to specify the class that contains the `static` factory method and an attribute
named `factory-method` to specify the name of the factory method itself. You should be
able to call this method (with optional arguments, as described later) and return a live
object, which subsequently is treated as if it had been created through a constructor.
One use for such a bean definition is to call `static` factories in legacy code.
The following bean definition specifies that the bean will be created by calling a
factory method. The definition does not specify the type (class) of the returned object,
but rather the class containing the factory method. In this example, the
`createInstance()` method must be a `static` method. The following example shows how to
specify a factory method:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean id="clientService"
class="examples.ClientService"
factory-method="createInstance"/>
----
The following example shows a class that would work with the preceding bean definition:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class ClientService {
private static ClientService clientService = new ClientService();
private ClientService() {}
public static ClientService createInstance() {
return clientService;
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class ClientService private constructor() {
companion object {
private val clientService = ClientService()
@JvmStatic
fun createInstance() = clientService
}
}
----
======
For details about the mechanism for supplying (optional) arguments to the factory method
and setting object instance properties after the object is returned from the factory,
see xref:core/beans/dependencies/factory-properties-detailed.adoc[Dependencies and Configuration in Detail].
[[beans-factory-class-instance-factory-method]]
=== Instantiation by Using an Instance Factory Method
Similar to instantiation through a xref:core/beans/definition.adoc#beans-factory-class-static-factory-method[static factory method]
, instantiation with an instance factory method invokes a non-static
method of an existing bean from the container to create a new bean. To use this
mechanism, leave the `class` attribute empty and, in the `factory-bean` attribute,
specify the name of a bean in the current (or parent or ancestor) container that contains
the instance method that is to be invoked to create the object. Set the name of the
factory method itself with the `factory-method` attribute. The following example shows
how to configure such a bean:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<!-- the factory bean, which contains a method called createClientServiceInstance() -->
<bean id="serviceLocator" class="examples.DefaultServiceLocator">
<!-- inject any dependencies required by this locator bean -->
</bean>
<!-- the bean to be created via the factory bean -->
<bean id="clientService"
factory-bean="serviceLocator"
factory-method="createClientServiceInstance"/>
----
The following example shows the corresponding class:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class DefaultServiceLocator {
private static ClientService clientService = new ClientServiceImpl();
public ClientService createClientServiceInstance() {
return clientService;
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class DefaultServiceLocator {
companion object {
private val clientService = ClientServiceImpl()
}
fun createClientServiceInstance(): ClientService {
return clientService
}
}
----
======
One factory class can also hold more than one factory method, as the following example shows:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean id="serviceLocator" class="examples.DefaultServiceLocator">
<!-- inject any dependencies required by this locator bean -->
</bean>
<bean id="clientService"
factory-bean="serviceLocator"
factory-method="createClientServiceInstance"/>
<bean id="accountService"
factory-bean="serviceLocator"
factory-method="createAccountServiceInstance"/>
----
The following example shows the corresponding class:
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
public class DefaultServiceLocator {
private static ClientService clientService = new ClientServiceImpl();
private static AccountService accountService = new AccountServiceImpl();
public ClientService createClientServiceInstance() {
return clientService;
}
public AccountService createAccountServiceInstance() {
return accountService;
}
}
----
Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class DefaultServiceLocator {
companion object {
private val clientService = ClientServiceImpl()
private val accountService = AccountServiceImpl()
}
fun createClientServiceInstance(): ClientService {
return clientService
}
fun createAccountServiceInstance(): AccountService {
return accountService
}
}
----
======
This approach shows that the factory bean itself can be managed and configured through
dependency injection (DI). See xref:core/beans/dependencies/factory-properties-detailed.adoc[Dependencies and Configuration in Detail]
.
NOTE: In Spring documentation, "factory bean" refers to a bean that is configured in the
Spring container and that creates objects through an
xref:core/beans/definition.adoc#beans-factory-class-instance-factory-method[instance] or
xref:core/beans/definition.adoc#beans-factory-class-static-factory-method[static] factory method. By contrast,
`FactoryBean` (notice the capitalization) refers to a Spring-specific
xref:core/beans/factory-extension.adoc#beans-factory-extension-factorybean[`FactoryBean`] implementation class.
[[beans-factory-type-determination]]
=== Determining a Bean's Runtime Type
The runtime type of a specific bean is non-trivial to determine. A specified class in
the bean metadata definition is just an initial class reference, potentially combined
with a declared factory method or being a `FactoryBean` class which may lead to a
different runtime type of the bean, or not being set at all in case of an instance-level
factory method (which is resolved via the specified `factory-bean` name instead).
Additionally, AOP proxying may wrap a bean instance with an interface-based proxy with
limited exposure of the target bean's actual type (just its implemented interfaces).
The recommended way to find out about the actual runtime type of a particular bean is
a `BeanFactory.getType` call for the specified bean name. This takes all of the above
cases into account and returns the type of object that a `BeanFactory.getBean` call is
going to return for the same bean name.
@@ -1,12 +0,0 @@
[[beans-dependencies]]
= Dependencies
:page-section-summary-toc: 1
A typical enterprise application does not consist of a single object (or bean in the
Spring parlance). Even the simplest application has a few objects that work together to
present what the end-user sees as a coherent application. This next section explains how
you go from defining a number of bean definitions that stand alone to a fully realized
application where objects collaborate to achieve a goal.
@@ -1,127 +0,0 @@
[[beans-factory-autowire]]
= Autowiring Collaborators
The Spring container can autowire relationships between collaborating beans. You can
let Spring resolve collaborators (other beans) automatically for your bean by
inspecting the contents of the `ApplicationContext`. Autowiring has the following
advantages:
* Autowiring can significantly reduce the need to specify properties or constructor
arguments. (Other mechanisms such as a bean template
xref:core/beans/child-bean-definitions.adoc[discussed elsewhere in this chapter] are also valuable
in this regard.)
* Autowiring can update a configuration as your objects evolve. For example, if you need
to add a dependency to a class, that dependency can be satisfied automatically without
you needing to modify the configuration. Thus autowiring can be especially useful
during development, without negating the option of switching to explicit wiring when
the code base becomes more stable.
When using XML-based configuration metadata (see xref:core/beans/dependencies/factory-collaborators.adoc[Dependency Injection]), you
can specify the autowire mode for a bean definition with the `autowire` attribute of the
`<bean/>` element. The autowiring functionality has four modes. You specify autowiring
per bean and can thus choose which ones to autowire. The following table describes the
four autowiring modes:
[[beans-factory-autowiring-modes-tbl]]
.Autowiring modes
[cols="20%,80%"]
|===
| Mode| Explanation
| `no`
| (Default) No autowiring. Bean references must be defined by `ref` elements. Changing
the default setting is not recommended for larger deployments, because specifying
collaborators explicitly gives greater control and clarity. To some extent, it
documents the structure of a system.
| `byName`
| Autowiring by property name. Spring looks for a bean with the same name as the
property that needs to be autowired. For example, if a bean definition is set to
autowire by name and it contains a `master` property (that is, it has a
`setMaster(..)` method), Spring looks for a bean definition named `master` and uses
it to set the property.
| `byType`
| Lets a property be autowired if exactly one bean of the property type exists in
the container. If more than one exists, a fatal exception is thrown, which indicates
that you may not use `byType` autowiring for that bean. If there are no matching
beans, nothing happens (the property is not set).
| `constructor`
| Analogous to `byType` but applies to constructor arguments. If there is not exactly
one bean of the constructor argument type in the container, a fatal error is raised.
|===
With `byType` or `constructor` autowiring mode, you can wire arrays and
typed collections. In such cases, all autowire candidates within the container that
match the expected type are provided to satisfy the dependency. You can autowire
strongly-typed `Map` instances if the expected key type is `String`. An autowired `Map`
instance's values consist of all bean instances that match the expected type, and the
`Map` instance's keys contain the corresponding bean names.
[[beans-autowired-exceptions]]
== Limitations and Disadvantages of Autowiring
Autowiring works best when it is used consistently across a project. If autowiring is
not used in general, it might be confusing to developers to use it to wire only one or
two bean definitions.
Consider the limitations and disadvantages of autowiring:
* Explicit dependencies in `property` and `constructor-arg` settings always override
autowiring. You cannot autowire simple properties such as primitives,
`Strings`, and `Classes` (and arrays of such simple properties). This limitation is
by-design.
* Autowiring is less exact than explicit wiring. Although, as noted in the earlier table,
Spring is careful to avoid guessing in case of ambiguity that might have unexpected
results. The relationships between your Spring-managed objects are no longer
documented explicitly.
* Wiring information may not be available to tools that may generate documentation from
a Spring container.
* Multiple bean definitions within the container may match the type specified by the
setter method or constructor argument to be autowired. For arrays, collections, or
`Map` instances, this is not necessarily a problem. However, for dependencies that
expect a single value, this ambiguity is not arbitrarily resolved. If no unique bean
definition is available, an exception is thrown.
In the latter scenario, you have several options:
* Abandon autowiring in favor of explicit wiring.
* Avoid autowiring for a bean definition by setting its `autowire-candidate` attributes
to `false`, as described in the xref:core/beans/dependencies/factory-autowire.adoc#beans-factory-autowire-candidate[next section].
* Designate a single bean definition as the primary candidate by setting the
`primary` attribute of its `<bean/>` element to `true`.
* Implement the more fine-grained control available with annotation-based configuration,
as described in xref:core/beans/annotation-config.adoc[Annotation-based Container Configuration].
[[beans-factory-autowire-candidate]]
== Excluding a Bean from Autowiring
On a per-bean basis, you can exclude a bean from autowiring. In Spring's XML format, set
the `autowire-candidate` attribute of the `<bean/>` element to `false`. The container
makes that specific bean definition unavailable to the autowiring infrastructure
(including annotation style configurations such as xref:core/beans/annotation-config/autowired.adoc[`@Autowired`]
).
NOTE: The `autowire-candidate` attribute is designed to only affect type-based autowiring.
It does not affect explicit references by name, which get resolved even if the
specified bean is not marked as an autowire candidate. As a consequence, autowiring
by name nevertheless injects a bean if the name matches.
You can also limit autowire candidates based on pattern-matching against bean names. The
top-level `<beans/>` element accepts one or more patterns within its
`default-autowire-candidates` attribute. For example, to limit autowire candidate status
to any bean whose name ends with `Repository`, provide a value of `*Repository`. To
provide multiple patterns, define them in a comma-separated list. An explicit value of
`true` or `false` for a bean definition's `autowire-candidate` attribute always takes
precedence. For such beans, the pattern matching rules do not apply.
These techniques are useful for beans that you never want to be injected into other
beans by autowiring. It does not mean that an excluded bean cannot itself be configured by
using autowiring. Rather, the bean itself is not a candidate for autowiring other beans.

Some files were not shown because too many files have changed in this diff Show More