Prior to this commit, an explicit override for an attribute in a
meta-annotation configured via @AliasFor could potentially result in an
incorrect override of an attribute of the same name but in the wrong
meta-annotation.
This commit fixes the algorithm in getAliasedAttributeName(Method,
Class) in AnnotationUtils by ensuring that an explicit attribute
override is only applied to the configured target meta-annotation
(i.e., configured via the 'annotation' attribute in @AliasFor).
Issue: SPR-13325
SPR-11512 introduced support for annotation attribute aliases via
@AliasFor, requiring the explicit declaration of the 'attribute'
attribute. However, for aliases within an annotation, this explicit
declaration is unnecessary.
This commit improves the readability of alias pairs declared within an
annotation by introducing a 'value' attribute in @AliasFor that is an
alias for the existing 'attribute' attribute. This allows annotations
such as @ContextConfiguration from the spring-test module to declare
aliases as follows.
public @interface ContextConfiguration {
@AliasFor("locations")
String[] value() default {};
@AliasFor("value")
String[] locations() default {};
// ...
}
Issue: SPR-13289
Prior to this commit, Spring's MimeType checked for equality between
two MIME types based on the equality of their properties maps; however,
the properties maps contain string representations of the "charset"
values. Thus, "UTF-8" is never equal to "utf-8" which breaks the
contract for character set names which must be compared in a
case-insensitive manner.
This commit addresses this issue by ensuring that "charset" properties
in MimeType instances are compared as Java Charset instances, thereby
ignoring case when checking for equality between charset names.
Issue: SPR-13157
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
This commit introduces support for automatically resolving a container
annotation configured via @Repeatable in AnnotationUtils'
getRepeatableAnnotations() and getDeclaredRepeatableAnnotations()
methods.
Issue: SPR-13068
This commit introduces a minor bug fix for getRepeatableAnnotations()
so that it fully complies with the contract of Java's
getAnnotationsByType() method with regard to repeatable annotations
declared on multiple superclasses.
Issue: SPR-13068
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
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
Prior to this commit, there existed several isEmpty() methods scattered
across various utilities such as ObjectUtils, CollectionUtils, and
StringUtils; however, each of these methods requires a cast to the type
supported for that particular variant.
This commit introduces a general-purpose isEmpty(Object) method in
ObjectUtils that transparently supports multiple object types in a
central location without the need for casts or juggling multiple
utility classes.
Issue: SPR-13119
Provide a mean to detect the actual ResolvableType based on a instance as
a counter measure to type erasure.
Upgrade the event infrastructure to detect if the event (or the payload)
implements such interface. When this is the case, the return value of
`getResolvableType` is used to validate its generic type against the
method signature of the listener.
Issue: SPR-13069
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
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
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
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
