Spring Framework 4.2 RC1 introduced support for synthesizing an
annotation from an existing annotation in order to provide additional
functionality above and beyond that provided by Java. Specifically,
such synthesized annotations provide support for @AliasFor semantics.
As luck would have it, the same principle can be used to synthesize an
annotation from any map of attributes, and in particular, from an
instance of AnnotationAttributes.
The following highlight the major changes in this commit toward
achieving this goal.
- Introduced AnnotationAttributeExtractor abstraction and refactored
SynthesizedAnnotationInvocationHandler to delegate to an
AnnotationAttributeExtractor.
- Extracted code from SynthesizedAnnotationInvocationHandler into new
AbstractAliasAwareAnnotationAttributeExtractor and
DefaultAnnotationAttributeExtractor implementation classes.
- Introduced MapAnnotationAttributeExtractor for synthesizing an
annotation that is backed by a map or AnnotationAttributes instance.
- Introduced a variant of synthesizeAnnotation() in AnnotationUtils
that accepts a map.
- Introduced findAnnotation(*) methods in AnnotatedElementUtils that
synthesize merged AnnotationAttributes back into an annotation of the
target type.
The following classes have been refactored to use the new support for
synthesizing AnnotationAttributes back into an annotation.
- ApplicationListenerMethodAdapter
- TestAnnotationUtils
- AbstractTestContextBootstrapper
- ActiveProfilesUtils
- ContextLoaderUtils
- DefaultActiveProfilesResolver
- DirtiesContextTestExecutionListener
- TestPropertySourceAttributes
- TestPropertySourceUtils
- TransactionalTestExecutionListener
- MetaAnnotationUtils
- MvcUriComponentsBuilder
- RequestMappingHandlerMapping
In addition, this commit also includes changes to ensure that arrays
returned by synthesized annotations are properly cloned first.
Issue: SPR-13067
This commit introduces first-class support for aliases for annotation
attributes. Specifically, this commit introduces a new @AliasFor
annotation that can be used to declare a pair of aliased attributes
within a single annotation or an alias from an attribute in a custom
composed annotation to an attribute in a meta-annotation.
To support @AliasFor within annotation instances, AnnotationUtils has
been overhauled to "synthesize" any annotations returned by "get" and
"find" searches. A SynthesizedAnnotation is an annotation that is
wrapped in a JDK dynamic proxy which provides run-time support for
@AliasFor semantics. SynthesizedAnnotationInvocationHandler is the
actual handler behind the proxy.
In addition, the contract for @AliasFor is fully validated, and an
AnnotationConfigurationException is thrown in case invalid
configuration is detected.
For example, @ContextConfiguration from the spring-test module is now
declared as follows:
public @interface ContextConfiguration {
@AliasFor(attribute = "locations")
String[] value() default {};
@AliasFor(attribute = "value")
String[] locations() default {};
// ...
}
The following annotations and their related support classes have been
modified to use @AliasFor.
- @ManagedResource
- @ContextConfiguration
- @ActiveProfiles
- @TestExecutionListeners
- @TestPropertySource
- @Sql
- @ControllerAdvice
- @RequestMapping
Similarly, support for AnnotationAttributes has been reworked to
support @AliasFor as well. This allows for fine-grained control over
exactly which attributes are overridden within an annotation hierarchy.
In fact, it is now possible to declare an alias for the 'value'
attribute of a meta-annotation.
For example, given the revised declaration of @ContextConfiguration
above, one can now develop a composed annotation with a custom
attribute override as follows.
@ContextConfiguration
public @interface MyTestConfig {
@AliasFor(
annotation = ContextConfiguration.class,
attribute = "locations"
)
String[] xmlFiles();
// ...
}
Consequently, the following are functionally equivalent.
- @MyTestConfig(xmlFiles = "test.xml")
- @ContextConfiguration("test.xml")
- @ContextConfiguration(locations = "test.xml").
Issue: SPR-11512, SPR-11513
Previously, a Bean implementing `AutoCloseable` (or `Closeable`) was
always destroyed regardless of its bean definition. In particular, the
documented way of disabling the destruction callback via an empty String
did not work.
AutoCloseable beans are now treated pretty much as any other bean: we
still use the presence of the interface to optimize the check of a
destroy method and we only auto-discover the method name to invoke if
the inferred mode is enabled.
Issue: SPR-13022
In general, the Spring Framework aims to construct error message
strings only if an actual error has occurred. This seems to be the
common pattern in the codebase and saves both CPU and memory. However,
there are some places where eager error message formatting occurs
unnecessarily.
This commit addresses this issue in the following classes:
AdviceModeImportSelector, AnnotationAttributes, and
ReadOnlySystemAttributesMap.
The change in ReadOnlySystemAttributesMap also avoids a potential
NullPointerException.
Issue: SPR-13007
Making sure that `GenericApplicationListenerAdapter` implements
`SmartApplicationListener` again as older code may try to cast an
instance to `SmartApplicationListener`.
Issue: SPR-8201
This commit introduces support for finding annotations on abstract,
bridge, and interface methods in AnnotatedElementUtils.
- Introduced dedicated findAnnotationAttributes() methods in
AnnotatedElementUtils that provide first-class support for
processing methods, class hierarchies, interfaces, bridge methods,
etc.
- Introduced find/get search algorithm dichotomy in
AnnotatedElementUtils which is visible in the public API as well as
in the internal implementation. This was necessary in order to
maintain backwards compatibility with the existing API (even though
it was undocumented).
- Reverted all recent changes made to the "get semantics" search
algorithm in AnnotatedElementUtils in order to ensure backwards
compatibility, and reverted recent changes to
JtaTransactionAnnotationParser and SpringTransactionAnnotationParser
accordingly.
- Documented internal AnnotatedElementUtils.Processor<T> interface.
- Enabled failing tests and introduced
findAnnotationAttributesFromBridgeMethod() test in
AnnotatedElementUtilsTests.
- Refactored ApplicationListenerMethodAdapter.getCondition() and
enabled failing test in TransactionalEventListenerTests.
- AnnotationUtils.isInterfaceWithAnnotatedMethods() is now package
private.
Issue: SPR-12738, SPR-11514, SPR-11598
Previously, a cache infrastructure with only a CacheResolver would have
worked fine until the JSR-107 API is added to the classpath. When this is
the case, the JCache support kicks in and an exception cache resolver is
all of the sudden required.
The CacheResolver _is_ different as the default implementation does look
different attributes so if a custom CacheResolver is set, it is not
possible to "reuse" it as a fallback exception CacheResolver.
Now, an exception CacheResolver is only required if a JSR-107 annotation
with an "exceptionCacheName" attribute is processed (i.e. the exception
CacheResolver is lazily instantiated if necessary).
The use case of having a CachingConfigurerSupport with only a
CacheResolver was still broken though since the JCache support only looks
for a JCacheConfigurer bean (per the generic type set on
AbstractCachingConfiguration). This has been fixed as well.
Issue: SPR-12850
Sam Brannen
Juergen Hoeller
Elizabeth Chatman
Stephane Nicoll
Philippe Marschall