Introduces getBeanProvider(Class) and getBeanProvider(ResolvableType), also narrowing getBean(String, Class) and isTypeMatch(String, Class) to a non-null Class argument and enriching NoUniqueBeanDefinitionException with a full ResolvableType. In addition, ObjectProvider supports iterable/stream access for collection-style resolution of multiple matching beans now, and collection injection falls back to an empty collection in a single-constructor case with non-null arguments.
Issue: SPR-17075
Issue: SPR-11419
Issue: SPR-15338
Allows for skipping the now-deprecated postProcessPropertyValues callback with its expensive PropertyDescriptor retrieval requirement. RequiredAnnotationBeanPostProcessor (which is dependent on postProcessPropertyValues) and the @Required annotation itself are also deprecated now: in favor of constructor injection (or afterPropertiesSet).
Issue: SPR-16918
Prior to this commit, a YAML entry that define an empty array value was
lost. This commit makes sure to flag it with an empty String, which
corresponds as an empty comma separated list of entries in the
properties format.
Issue: SPR-16769
Includes efficient check for same ClassLoader in ClassUtils.isVisible, efficient MethodMatchers check for IntroductionAwareMethodMatcher, and supertype method resolution in MethodMapTransactionAttributeSource.
Issue: SPR-16723
Spring's CGLIB fork is patched with local copies of affected files here, introducing the notion of a "contextClass" (e.g. the proxy superclass) which gets passed through to ReflectUtils.defineClass for delegating to MethodHandles.Lookup.defineClass eventually, against a privateLookupIn(contextClass) lookup context on JDK 9/10/11.
Issue: SPR-15859
Includes unified detection of Kotlin's optional parameters in MethodParameter.isOptional(), reduces BeanUtils.findPrimaryConstructor to Kotlin semantics (for reuse in AutowiredAnnotationBeanPostProcessor), and finally introduces a common KotlinDetector delegate with an isKotlinType(Class) check.
Issue: SPR-15877
Issue: SPR-16020
Bean-derived null values may still get passed into bean properties and injection points but only if those are declared as non-required. Note that getBean will never return null; a manual bean.equals(null) / "null".equals(bean.toString()) check identifies expected null values now. This will only ever happen with custom FactoryBeans or factory methods returning null - and since all common cases are handled by autowiring or bean property values in bean definitions, there should be no need to ever manually check for such a null value received from getBean.
Issue: SPR-15829
This commit updates BeanUtils class in order to add Kotlin optional
parameters with default values support to the immutable data classes
support introduced by SPR-15199.
Issue: SPR-15673
Beyond just formally declaring the current behavior, this revision actually enforces non-null behavior in selected signatures now, not tolerating null values anymore when not explicitly documented. It also changes some utility methods with historic null-in/null-out tolerance towards enforced non-null return values, making them a proper citizen in non-null assignments.
Some issues are left as to-do: in particular a thorough revision of spring-test, and a few tests with unclear failures (ignored as "TODO: NULLABLE") to be sorted out in a follow-up commit.
Issue: SPR-15540
Juergen Hoeller