Prior to this commit, @ComponentScan already had a value/basePackages
alias pair; however, the semantics were not properly enforced.
This commit addresses this issue by refactoring
ComponentScanAnnotationParser to ensure that it is not possible to
declare both of the aliased attributes. In addition, the 'value' and
'basePackages' attributes are now annotated with @AliasFor in order to
make the semantics clearer.
Issue: SPR-11393
This commit introduces a "synthesized annotation" alternative to
getAnnotationAttributes() in AnnotatedElementUtils, analogous to the
recently introduced findAnnotation() methods.
Issue: SPR-13082
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
Prior to this commit, when a nested array of annotations was
synthesized while adapting values within an AnnotationAttributes map,
the array was improperly replaced with an array of type Annotation[]
instead of an array of the concrete annotation type, which can lead to
unexpected run-time exceptions.
This commit fixes this bug by replacing annotations in the existing
array with synthesized versions of those annotations, thereby retaining
the original array's component type.
Issue: SPR-13077
This commit introduces support in AnnotationAttributes for retrieving
nested annotations that is on par with the existing type-safe support
for retrieving nested AnnotationAttributes.
Issue: SPR-13074
AnnotationAttributes has existed for several years, but none of the
"get" methods that make up its public API are documented. In many
cases, the behavior can be inferred from the name of the method, but
for some methods there are "hidden gems" and unexpected behavior
lurking behind the scenes.
This commit addresses this issue by documenting all public methods. In
addition, the hidden support for converting single elements into
single-element arrays has also been documented and tested.
Issue: SPR-13072
Sam Brannen
Juergen Hoeller