Issue: SPR-11512

Issue: SPR-11512

This commit also introduces a cache for attribute alias metadata.

Issue: SPR-11512

Issue: SPR-13064

Issue: SPR-11512

Issue: SPR-11512

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

Issue: SPR-12926

Prior to this commit, the documentation in AnnotationUtils was
inconsistent, and at times even misleading, with regard to finding
annotations that are "present" or "directly present" on annotated
elements.

This commit defines the terminology used within AnnotationUtils and
introduces the explicit notion of "meta-present" to denote that
annotations are present within annotation hierarchies above annotated
elements.

Issue: SPR-13030

This commit improves the documentation for AnnotationUtils and
AnnotatedElementUtils by explaining that the scope of most annotation
searches is limited to finding the first such annotation, resulting in
additional such annotations being silently ignored.

Issue: SPR-13015

This commit picks up where SPR-11483 left off, with the goal of
eliminating all unnecessary inspection of core JDK annotations in
Spring's annotation search algorithms in AnnotatedElementUtils and
AnnotationMetadataReadingVisitor.

Issue: SPR-12989

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

Prior to this commit, the search algorithm used by the
findAnnotation(Method, Class) method in AnnotationUtils only found
direct annotations or direct meta-annotations (i.e., one level of
meta-annotations).

This commit reworks the search algorithm so that it supports arbitrary
levels of meta-annotations on methods. To make this possible, a new
findAnnotation(AnnotatedElement, Class) method has been introduced in
AnnotationUtils.

This fix also allows for the @Ignore'd tests in
TransactionalEventListenerTests to be re-enabled.

Issue: SPR-12941

Issue: SPR-12940

Also refines logIntrospectionFailure to just log at debug level for meta-annotation introspection failures.

Issue: SPR-12889

AnnotationUtils.getAnnotationAttributes makes Method accessible (analogous to AnnotationUtils.getValue)

Issue: SPR-12858

Issue: SPR-12604

This commit updates the Javadoc for findAnnotation() to reflect recent
changes to the algorithm it implements.

Issue: SPR-12493

Normalized AnnotationAttributesReadingVisitor class layout and improved diagnostics through delegating to AnnotationUtils

Issue: SPR-12387

Issue: SPR-12325

AnnotationUtils favors local composed annotations over interface annotations and consistently logs introspection failures via lazily initialized logger

Issue: SPR-12355
Issue: SPR-12325
Issue: SPR-12329

Issue: SPR-12065

ReflectionUtils caches Class.getDeclaredMethods() results; AnnotationUtils caches findAnnotation results

Issue: SPR-11882

AnnotationUtils defensively catches and logs unexpected exceptions from retrieval attempts (proceeding like the annotation wasn't there)

Issue: SPR-11874

AnnotationUtils defensively catches unexpected exceptions from retrieval attempts (proceeding like the annotation wasn't there)

This is analogous to what the JVM does for cases where the annotation type itself isn't present on the classpath. We're effectively extending that policy to values referenced within an annotation declaration.

Issue: SPR-11874

Prior to this commit, Spring supported meta-annotation attribute
overrides in custom composed annotations with reflection-based
annotation processing but not with ASM-based annotation processing.

This commit ensures that meta-annotation attribute overrides are
supported in AnnotationMetadataReadingVisitor.getAnnotationAttributes().

Issue: SPR-11574

The previous commit introduced a dependency on
Class.getDeclaredAnnotation() which is a Java 8 API.

This commit refactors AnnotationUtils.findAnnotation(Class, Class, Set)
to use Class.getAnnotation() in conjunction with
isAnnotationDeclaredLocally() in order to achieve the same desired
behavior.

Issue: SPR-11475

Prior to this commit, the implementations of findAnnotation() in
AnnotationUtils and getAnnotationAttributes() in AnnotatedElementUtils
favored inherited annotations and inherited composed annotations over
composed annotations that are declared closer to the starting class
passed to these methods.

This commit addresses this issue as follows:

- Refactored AnnotationUtils to use getDeclaredAnnotation() and
  getDeclaredAnnotations() instead of getAnnotation() and
  getAnnotations() where appropriate.

- AnnotatedElementUtils.doProcess() supports a traverseClassHierarchy
  flag to control whether the class hierarchy should be traversed,
  using getDeclaredAnnotations() instead of getAnnotations() if the
  flag is true.

- Overhauled Javadoc in AnnotatedElementUtils.

Issue: SPR-11475

This commit introduces a new isInJavaLangAnnotationPackage(Annotation)
method in AnnotationUtils. This method is now used in AnnotationUtils,
AnnotatedElementUtils, and MetaAnnotationUtils to ensure that search
algorithms do no search for meta-annotations on annotations in the
"java.lang.annotation" package.

The following are some empirical results from this change:

- The number of times that the findAnnotation(Class,Class,Set) method in
  AnnotationUtils is recursively invoked while executing
  AnnotationUtilsTests drops from 51 to 29.

- The number of times that the process(AnnotatedElement) method in
  AnnotationUtils.AnnotationCollector is recursively invoked while
  executing AnnotationUtilsTests.getRepeatableFromMethod() drops
  from 16 to 2.

- The number of times that the doProcess() method in
  AnnotatedElementUtils is recursively invoked while executing the
  "getAnnotationAttributes() On MetaCycleAnnotatedClass with missing
  target meta-annotation" test in AnnotatedElementUtilsTests drops
  from 23 to 5.

- The number of times that the findAnnotationDescriptor(Class,Set,Class)
  method in MetaAnnotationUtils is recursively invoked while executing
  the "findAnnotationDescriptor() on MetaCycleAnnotatedClass with
  missing target meta-annotation" test in MetaAnnotationUtilsTests drops
  from 16 to 8.

Issue: SPR-11483