See gh-19930

This is a work in progress (WIP) which includes failing tests.

See gh-19930

This commit updates URLs to prefer the https protocol. Redirects are not followed to avoid accidentally expanding intentionally shortened URLs (i.e. if using a URL shortener).

# Fixed URLs

## Fixed Success
These URLs were switched to an https URL with a 2xx status. While the status was successful, your review is still recommended.

* [ ] http://www.apache.org/licenses/ with 1 occurrences migrated to:
  https://www.apache.org/licenses/ ([https](https://www.apache.org/licenses/) result 200).
* [ ] http://www.apache.org/licenses/LICENSE-2.0 with 6515 occurrences migrated to:
  https://www.apache.org/licenses/LICENSE-2.0 ([https](https://www.apache.org/licenses/LICENSE-2.0) result 200).

This commit updates URLs to prefer the https protocol. Redirects are not followed to avoid accidentally expanding intentionally shortened URLs (i.e. if using a URL shortener).

# Fixed URLs

## Fixed Success
These URLs were switched to an https URL with a 2xx status. While the status was successful, your review is still recommended.

* [ ] http://www.apache.org/licenses/ with 1 occurrences migrated to:
  https://www.apache.org/licenses/ ([https](https://www.apache.org/licenses/) result 200).
* [ ] http://www.apache.org/licenses/LICENSE-2.0 with 6625 occurrences migrated to:
  https://www.apache.org/licenses/LICENSE-2.0 ([https](https://www.apache.org/licenses/LICENSE-2.0) result 200).

Reorganize imports to ensure consistent ordering. This commit also
expands any `.*` static imports in favor of using fully-qualified
method references.

Issue: SPR-16968

This commit also removes nullability from two common spots: ResolvableType.getType() and TargetSource.getTarget(), both of which are never effectively null with any regular implementation. For such scenarios, a non-null empty type/target is the cleaner contract.

Issue: SPR-15540

This commit makes use of the new Supplier<String> variants of utility
methods in org.springframework.util.Assert within the spring-test
module.

Issue: SPR-14450

Issue: SPR-13188

Issue: SPR-13440

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

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

Work done in conjunction with SPR-5243 and SPR-4588 introduced physical
package cycles in the spring-test module. The work performed in
conjunction with SPR-9924 uses reflection to resolve these physical
package cycles; however, prior to this commit the logical package
cycles still remain.

Furthermore, over time it has become apparent that the Spring
TestContext Framework (TCF) could better serve application developers
and especially third-party framework developers by providing a more
flexible mechanism for "bootstrapping" the TCF. For example, prior to
this commit, default TestExecutionListeners could only be registered by
subclassing TestContextManager (and SpringJUnit4ClassRunner if using
JUnit). Similarly, the default ContextLoader could only be set by
subclassing SpringJUnit4ClassRunner for JUnit and by copying and
modifying AbstractTestNGSpringContextTests for TestNG.

This commit addresses the aforementioned issues by introducing a
bootstrap strategy in the TestContext framework that is responsible for
determining default TestExecutionListeners and the default
ContextLoader in an extensible fashion. The new TestContextBootstrapper
SPI also provides a mechanism for supporting various types of
MergedContextConfiguration depending on the feature set of the context
loaders supported by the strategy.

The following provides an overview of the most significant changes in
this commit.

 - Introduced TestContextBootstrapper strategy SPI, BootstrapContext,
   and @BootstrapWith.

 - Introduced AbstractTestContextBootstrapper,
   DefaultTestContextBootstrapper, and WebTestContextBootstrapper
   implementations of the TestContextBootstrapper SPI and extracted
   related reflection code from ContextLoaderUtils & TestContextManager.

 - Introduced BootstrapUtils for retrieving the TestContextBootstrapper
   from @BootstrapWith, falling back to a default if @BootstrapWith is
   not present.

 - @WebAppConfiguration is now annotated with
   @BootstrapWith(WebTestContextBootstrapper.class).

 - CacheAwareContextLoaderDelegate is now an interface with a new
   DefaultCacheAwareContextLoaderDelegate implementation class.

 - Introduced closeContext(MergedContextConfiguration, HierarchyMode) in
   CacheAwareContextLoaderDelegate.

 - DefaultTestContext now uses CacheAwareContextLoaderDelegate instead
   of interacting directly with the ContextCache.

 - DefaultTestContext now delegates to a TestContextBootstrapper for
   building the MergedContextConfiguration.

 - TestContextManager now delegates to TestContextBootstrapper for
   retrieving TestExecutionListeners.

 - Deleted TestContextManager(Class, String) constructor and
   SpringJUnit4ClassRunner.getDefaultContextLoaderClassName(Class)
   method since default ContextLoader support is now implemented by
   TestContextBootstrappers.

 - Extracted ActiveProfilesUtils from ContextLoaderUtils.

 - Extracted ApplicationContextInitializerUtils from ContextLoaderUtils.

 - MetaAnnotationUtils is now a public utility class in the test.util
   package.

 - Removed restriction in @ActiveProfiles that a custom resolver cannot
   be used with the 'value' or 'profiles' attributes.

 - Introduced DefaultActiveProfilesResolver.

Issue: SPR-9955