We have had an ObjectToOptionalConverter since Spring Framework 4.1;
however, prior to this commit we did not have a standard Converter for
the inverse (Optional to Object).
To address that, this commit introduces an OptionalToObjectConverter
that unwraps an Optional, using the ConversionService to convert the
object contained in the Optional (potentially null) to the target type.
This allows for conversions such as the following.
- Optional.empty() -> null
- Optional.of(42) with Integer target -> 42
- Optional.of(42) with String target -> "42"
- Optional.of(42) with Optional<String> target -> Optional.of("42")
The OptionalToObjectConverter is also registered by default in
DefaultConversionService, alongside the existing
ObjectToOptionalConverter.
See gh-20433
Closes gh-34544
Prior to this commit, Spring Framework would use its own ASM fork to
read class/method/annotation metadata from bytecode. This is typically
used in configuration class parsing to build bean definitions without
actually loading classes at runtime at that step.
This commit adds support for a new metadata reading implementation that
uses the ClassFile API available as of Java 24. For now, this is turned
on by default for Java 24+.
Closes gh-33616
This commit updates the Javadoc in various places to reflect the fact
that support for convention-based annotation attribute overrides has
been removed.
See gh-28761
Historically, the Spring Framework first had support for repeatable
annotations based on convention and later added explicit support for
Java 8's @Repeatable facility. Consequently, the support for both
types of repeatable annotations has grown a bit intertwined over the
years. However, modern Java applications typically make use of
@Repeatable, and convention-based repeatable annotations have become
more of a niche.
The RepeatableContainers API supports both types of repeatable
annotations with @Repeatable support being the default. However,
RepeatableContainers.of() makes it very easy to enable support for
convention-based repeatable annotations while accidentally disabling
support for @Repeatable, which can lead to subtle bugs – for example,
if convention-based annotations are combined with @Repeatable
annotations. In addition, it is not readily clear how to combine
@Repeatable support with convention-based repeatable annotations.
In light of the above, this commit revises the RepeatableContainers API
to better guide developers to use @Repeatable support for almost all
use cases while still supporting convention-based repeatable
annotations for special use cases.
Specifically:
- RepeatableContainers.of() is now deprecated in favor of the new
RepeatableContainers.explicitRepeatable() method.
- RepeatableContainers.and() is now deprecated in favor of the new
RepeatableContainers.plus() method which declares the repeatable and
container arguments in the same order as the rest of Spring
Framework's repeated annotation APIs.
For example, instead of the following confusing mixture of
repeatable/container and container/repeatable:
RepeatableContainers.of(A.class, A.Container.class)
.and(B.Container.class, B.class)
Developers are now be able to use:
RepeatableContainers.explicitRepeatable(A.class, A.Container.class)
.plus(B.class, B.Container.class)
This commit also overhauls the Javadoc for RepeatableContainers and
explicitly points out that the following is the recommended approach to
support convention-based repeatable annotations while retaining support
for @Repeatable.
RepeatableContainers.standardRepeatables()
.plus(MyRepeatable1.class, MyContainer1.class)
.plus(MyRepeatable2.class, MyContainer2.class)
See gh-20279
Closes gh-34637
This commit extracts AnnotatedElementAdapter from TypeDescriptor and
introduces it as a public, top-level type in the
org.springframework.core.annotation package, and
AnnotatedElementUtils.forAnnotations() now returns an instance of
AnnotatedElementAdapter instead of AnnotatedElementForAnnotations which
has been removed.
In addition, this commit adds missing Javadoc for
AnnotatedElementAdapter and refines some of the implementation.
Closes gh-34628
This commit removes the BDDMockito Checkstyle rule, since it did not
actually enforce the use of BDDMockito.
This commit also updates static imports to use Mockito instead of
BDDMockito where appropriate (automated via the Eclipse IDE Organize
Imports clean-up task).
Closes gh-34616
Unfortunately, it is not possible to raise the byte code level beyond
Java 1.8 for classes generated using CGLIB due to the fact that CGLIB
generates STATICHOOK methods which set static final fields outside the
initializer method <clinit> (i.e., a static initialization block).
Attempting to raise the level to Java 17 (or even Java 9) results in
exceptions like the following.
Caused by: java.lang.IllegalAccessError: Update to static final field
org.example.MyBean$$SpringCGLIB$$0.CGLIB$THREAD_CALLBACKS attempted from
a different method (CGLIB$STATICHOOK1) than the initializer method <clinit>
at org.example.MyBean$$SpringCGLIB$$0.CGLIB$STATICHOOK1(<generated>)
at org.example.MyBean$$SpringCGLIB$$0.<clinit>(<generated>)
This commit therefore introduces inline comments pointing out why we
stay with Java 1.8 byte code level with CGLIB.
See gh-34602
This commit completely removes all support for convention-based
annotation attribute overrides in Spring's annotation utilities and the
MergedAnnotations infrastructure.
Composed annotations must now use @AliasFor to declare explicit
overrides for attributes in meta-annotations.
See gh-28760
Closes gh-28761
Sam Brannen