This commit introduces a convenience method in AnnotationUtils for
synthesizing an annotation from its default attribute values.

TransactionalTestExecutionListener has been refactored to invoke this
new convenience method.

Issue: SPR-13087

Prior to this commit, the implementation of getRepeatableAnnotation()
in Spring's AnnotationUtils complied neither with the contract of
getAnnotationsByType() nor with the contract of
getDeclaredAnnotationsByType() as defined in AnnotatedElement in Java 8.

Specifically, unexpected results can be encountered when using Spring's
support for @Repeatable annotations: either annotations show up in the
returned set in the wrong order, or annotations are returned in the set
that should not even be found based on the semantics of @Repeatable.

This commit remedies this problem by deprecating the existing
getRepeatableAnnotation() methods and replacing them with new
getRepeatableAnnotations() and getDeclaredRepeatableAnnotations()
methods that comply with the contracts of Java's getAnnotationsByType()
and getDeclaredAnnotationsByType(), respectively.

Issue: SPR-13068

The initial support for synthesizing an annotation from a Map (or
AnnotationAttributes) introduced in SPR-13067 required that the map
contain key-value pairs for every attribute defined by the supplied
annotationType. However, there are use cases that would benefit from
being able to supply a reduced set of attributes and still have the
annotation synthesized properly.

This commit refines the validation mechanism in
MapAnnotationAttributeExtractor so that a reduced set of attributes may
be supplied. Specifically, if an attribute is missing in the supplied
map the attribute will be set either to value of its alias (if an alias
value configured via @AliasFor exists) or to the value of the
attribute's default value (if defined), and otherwise an exception will
be thrown.

Furthermore, TransactionalTestExecutionListener has been refactored to
take advantage of this new feature by synthesizing an instance of
@TransactionConfiguration solely from the default values of its
declared attributes.

Issue: SPR-13087

Prior to this change, `XpathResultMatchers` and more generally the
`MockHttpServletResponse` would default to ISO-8859-1 encoding even when
it's not supposed to. The Servlet/HTTP specs mention this encoding
for all `text/*` mime types when decoding bodies to Strings, but this
issue is about XML Parsers.

XML Parsers should use the encoding:

* defined in the `Content-Type` response header (if available)
* written in the XML declaration of the document
* "guessed" by a built-in auto-detection mechanism

This commit changes the following:

* XPathMatchers now feed the XML parser with byte arrays instead of
decoded Strings
* the response should be written to `MockHttpServletResponse` using
its OutputStream, and not a PrintWriter which defaults to ISO-8859-1

Issue: SPR-12676

Ever since @ActiveProfiles was introduced, the declared active profiles
for integration tests have been sorted in order to support unique cache
key generation; however, there are use cases for which the original
ordering should be retained.

For example, Spring Boot's ConfigFileApplicationListener loads
configuration files for active profiles in the order returned by
Environment.getActiveProfiles(), with the assumption that the ordering
matches the order in which the developer declared the active profiles.

This commit maintains the uniqueness of active profiles declared via
@ActiveProfiles but no longer sorts them.

Issue: SPR-12492

In AnnotatedElementUtils, all methods pertaining to merging annotation
attributes have been renamed to "getMerged*()" and "findMerged*()"
accordingly. Existing methods such as getAnnotationAttributes(..) have
been deprecated in favor of the more descriptive "merged" variants.
This aligns the naming conventions in AnnotatedElementUtils with those
already present in AnnotationReadingVisitorUtils.

The use of "annotationType" as a variable name for the fully qualified
class name of an annotation type has been replaced with
"annotationName" in order to improve the readability and intent of the
code base.

In MetaAnnotationUtils.AnnotationDescriptor, getMergedAnnotation() has
been renamed to synthesizeAnnotation(), and the method is now
overridden in UntypedAnnotationDescriptor to always throw an
UnsupportedOperationException in order to avoid potential run-time
ClassCastExceptions.

Issue: SPR-11511

Issue: SPR-11393

The modifications to DefaultMockMvcBuilder performed in conjunction
with SPR-12553 introduced a breaking change: the WebApplicationContext
supplied to DefaultMockMvcBuilder's constructor was *always* stored in
the ServletContext as the root WebApplicationContext, overwriting a
root WebApplicationContext that had been set by the user or by the
Spring TestContext Framework (TCF) -- for example, in
AbstractGenericWebContextLoader. Consequently, the changes in SPR-12553
cause tests that use @ContextHierarchy to fail if web components rely
on the correct WebApplicationContext being stored under the
WebApplicationContext#ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE key.

This commit reverts the breaking changes introduced in SPR-12553: if
the root WebApplicationContext has already been set in the
ServletContext of the WebApplicationContext supplied to
DefaultMockMvcBuilder, no action is taken.

Furthermore, this commit introduces new code to address the initial
intent of SPR-12553. Specifically, if the root WebApplicationContext
has NOT been set in the ServletContext of the WebApplicationContext
supplied to DefaultMockMvcBuilder, the application context hierarchy
will be traversed in search of the root WebApplicationContext, and the
root WebApplicationContext will then be stored under the
ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE key.

Issue: SPR-13075, SPR-12553

Issue: SPR-11393

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

Issue: SPR-12926

Remove unused imports

In order to simplify configuration of the SpringMethodRule and to ensure
that the correct TestContextManager is always retrieved for the
currently executing test class, this commit introduces a static
TestContextManager cache in SpringClassRule.

In addition, since it is not foreseen that SpringClassRule and
SpringMethodRule should be able to be subclassed, their internal methods
are now private instead of protected.

Issue: SPR-7731

Since Spring Framework 2.5, support for integrating the Spring
TestContext Framework (TCF) into JUnit 4 based tests has been provided
via the SpringJUnit4ClassRunner, but this approach precludes the
ability for tests to be run with alternative runners like JUnit's
Parameterized or third-party runners such as the MockitoJUnitRunner.

This commit remedies this situation by introducing @ClassRule and @Rule
based alternatives to the SpringJUnit4ClassRunner. These rules are
independent of any Runner and can therefore be combined with
alternative runners.

Due to the limitations of JUnit's implementation of rules, as of JUnit
4.12 it is currently impossible to create a single rule that can be
applied both at the class level and at the method level (with access to
the test instance). Consequently, this commit introduces the following
two rules that must be used together.

 - SpringClassRule: a JUnit TestRule that provides the class-level
   functionality of the TCF to JUnit-based tests

 - SpringMethodRule: a JUnit MethodRule that provides the
   instance-level and method-level functionality of the TCF to
   JUnit-based tests

In addition, this commit also introduces the following new JUnit
Statements for use with rules:

 - RunPrepareTestInstanceCallbacks

 - ProfileValueChecker

Issue: SPR-7731

This commit updates code that previously used getAnnotationAttributes()
in AnnotatedElementUtils to use findAnnotationAttributes(), where
appropriate.

Issue: SPR-12738

Issue: SPR-13005

This commit introduces support in the spring-test module for obtaining a
reference to the underlying target object hidden behind one or more
proxies.

Specifically this commit introduces AopTestUtils with two methods:

 - getTargetObject(Object)

 - getUltimateTargetObject(Object)

Issue: SPR-13005

Prior to this commit it was possible for two @BootstrapWith annotations
to be 'present' on a test class -- for example, via competing custom
composed annotations. However, only one of the annotations will ever be
used to bootstrap the TestContext Framework. Thus, in such scenarios
one of the annotations will be silently ignored.

This commit introduces a check for such scenarios. BootstrapUtils'
resolveTestContextBootstrapper() method now throws an
IllegalStateException if more than one @BootstrapWith annotation is
'present' on a given test class.

Issue: SPR-12602

Previously MockHttpServletRequestBuilder merge method would append the
parent's (default) RequestPostProcessor implementations to the end. This
means that the default RequestPostProcessor implementations would override
values set by previous RequestPostProcessor implementations.

This commit ensures that the default RequestPostProcessor are preformed
first so that additional RequestPostProcessor implementations override
the defaults.

Issue: SPR-12945

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, AnnotationAttributes retrieved from
MetaAnnotationUtils's AnnotationDescriptor could contain attributes
from the wrong annotation if an inherited annotation shadowed a locally
declared composed annotation.

This commit addresses this issue by invoking the new
getAnnotationAttributes() method in AnnotatedElementUtils that provides
a flag to control whether superclasses should be searched -- which
coincidentally processes local annotations before searching the class
hierarchy.

Issue: SPR-12749, SPR-11598

Since the ContextCache is now a published SPI, it and its collaborators
have been moved to a dedicated 'org.sfw.test.context.cache' subpackage.

Issue: SPR-12683

Issue: SPR-12597

This commit adds an assertion to DefaultTestContext's
getApplicationContext() method to ensure that a context loaded by the
Spring TestContext Framework (TCF) or retrieved from the ContextCache
is still active. This extra check helps to avoid situations where
developers manually close a cached context instead of relying on the
@DirtiesContext support.

Issue: SPR-12932