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

Issue: SPR-13066

Issue: SPR-13065

Issue: SPR-13064

This commit introduces a test that will fail if SynthesizedAnnotation is
not public as is required by the contract for getProxyClass() in
java.lang.reflect.Proxy.

Issue: SPR-13057

Includes an optimization for simple ByteBuffer duplication.

Issue: SPR-13056

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

Remove unused imports

ByteBufferConverter also defensively returns the rewind result now.

Issue: SPR-13031

Provide Converter implementations for Charset, Currency and TimeZone as
related PropertyEditors are available for those.

Issue: SPR-13020

This commit updates the "get semantics" search algorithm used in
`AnnotatedElementUtils` so that locally declared 'composed annotations'
are favored over inherited annotations.

Specifically, the internal `searchWithGetSemantics()` method now
searches locally declared annotations before searching inherited
annotations.

All TODOs in `AnnotatedElementUtilsTests` have been completed, and all
ignored tests have been reinstated.

Issue: SPR-11598

(cherry picked from commit 9e925aa8)

Issue: SPR-13007

Issue: SPR-12998

Prior to this commit, the `getAnnotation()` method in `TypeDescriptor`
only supported a single level of meta-annotations. In other words, the
annotation hierarchy would not be exhaustively searched.

This commit provides support for arbitrary levels of meta-annotations
in `TypeDescriptor` by delegating to `AnnotationUtils.findAnnotation()`
within `TypeDescriptor.getAnnotation()`.

Issue: SPR-12793

Issue: SPR-12998

Prior to this commit, AntPathMatcher would not correctly combine a path
that ends with a separator with a path that starts with a separator.
For example, `/foo/` + `/bar` combined into `/foo//bar`.

Specifically, this commit:

 - Removes the duplicated separator in combined paths

 - Improves RequestMappingInfo's toString() representation

 - Fixes Javadoc formatting in AntPathMatcher

 - Polishes AntPathMatcherTests

 - Polishes Javadoc in AbstractRequestCondition

Issue: SPR-12975

Issue: SPR-12003

Issue: SPR-12971

Issue: SPR-11514

Issue: SPR-11514

Issue: SPR-11514

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

 - Methods which search for a specific annotation now properly ensure
   that the sought annotation was actually found.

 - Both the "get" and the "find" search algorithms no longer needlessly
   traverse meta-annotation hierarchies twice.

 - Both the "get" and the "find" search algorithms now properly
   increment the metaDepth when recursively searching within the
   meta-annotation hierarchy.

 - Redesigned getMetaAnnotationTypes() so that it doesn't needlessly
   search irrelevant annotations.

 - Documented and tested hasMetaAnnotationTypes().

 - Documented isAnnotated().

Issue: SPR-11514

This commit documents the status quo for the getMetaAnnotationTypes()
method in AnnotatedElementUtils and adds appropriate regression tests to
AnnotatedElementUtilsTests.

In addition, this commit also introduces a SimpleAnnotationProcessor
base class in AnnotatedElementUtils.

Issue: SPR-11514

Issue: SPR-12738

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

This commit introduces support in AnnotatedElementUtils for finding
annotations declared on interfaces at the type level.

NB: this commit does not include support for finding annotations
declared on interface methods.

In order to maintain backward compatibility with @Transactional
annotation attribute processing, a new getAnnotationAttributes() method
has been added to AnnotatedElementUtils that provides a flag to control
whether interfaces should be searched.
SpringTransactionAnnotationParser and JtaTransactionAnnotationParser
have been updated accordingly to ensure that interfaces are not
unintentionally searched in the @Transactional resolution process.

This commit also introduces additional tests and updates TODOs for
SPR-12738.

Issue: SPR-12944, SPR-12738

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