类 AnnotationUtils

字段详细资料

• VALUE

  public static final String VALUE

  The attribute name for annotations with a single element.

  另请参阅:

  常量字段值

构造器详细资料

• AnnotationUtils

  public AnnotationUtils()

方法详细资料

• isCandidateClass

  public static boolean isCandidateClass​(Class<?> clazz,
                                         Collection<Class<? extends Annotation>> annotationTypes)

  Determine whether the given class is a candidate for carrying one of the specified annotations (at type, method or field level).

  参数:

  clazz - the class to introspect

  annotationTypes - the searchable annotation types

  返回:

  false if the class is known to have no such annotations at any level; true otherwise. Callers will usually perform full method/field introspection if true is being returned here.

  从以下版本开始:

  5.2

  另请参阅:

  isCandidateClass(Class, Class), isCandidateClass(Class, String)

• isCandidateClass

  public static boolean isCandidateClass​(Class<?> clazz,
                                         Class<? extends Annotation> annotationType)

  Determine whether the given class is a candidate for carrying the specified annotation (at type, method or field level).

  参数:

  clazz - the class to introspect

  annotationType - the searchable annotation type

  返回:

  false if the class is known to have no such annotations at any level; true otherwise. Callers will usually perform full method/field introspection if true is being returned here.

  从以下版本开始:

  5.2

  另请参阅:

  isCandidateClass(Class, String)

• isCandidateClass

  public static boolean isCandidateClass​(Class<?> clazz,
                                         String annotationName)

  Determine whether the given class is a candidate for carrying the specified annotation (at type, method or field level).

  参数:

  clazz - the class to introspect

  annotationName - the fully-qualified name of the searchable annotation type

  返回:

  false if the class is known to have no such annotations at any level; true otherwise. Callers will usually perform full method/field introspection if true is being returned here.

  从以下版本开始:

  5.2

  另请参阅:

  isCandidateClass(Class, Class)

• getAnnotation

  @Nullable
  public static <A extends Annotation> A getAnnotation​(Annotation annotation,
                                                       Class<A> annotationType)

  Get a single Annotation of annotationType from the supplied annotation: either the given annotation itself or a direct meta-annotation thereof.

  Note that this method supports only a single level of meta-annotations. For support for arbitrary levels of meta-annotations, use one of the find*() methods instead.

  参数:

  annotation - the Annotation to check

  annotationType - the annotation type to look for, both locally and as a meta-annotation

  返回:

  the first matching annotation, or null if not found

  从以下版本开始:

  4.0

• getAnnotation

  @Nullable
  public static <A extends Annotation> A getAnnotation​(AnnotatedElement annotatedElement,
                                                       Class<A> annotationType)

  Get a single Annotation of annotationType from the supplied AnnotatedElement, where the annotation is either present or meta-present on the AnnotatedElement.

  Note that this method supports only a single level of meta-annotations. For support for arbitrary levels of meta-annotations, use findAnnotation(AnnotatedElement, Class) instead.

  参数:

  annotatedElement - the AnnotatedElement from which to get the annotation

  annotationType - the annotation type to look for, both locally and as a meta-annotation

  返回:

  the first matching annotation, or null if not found

  从以下版本开始:

  3.1

• getAnnotation

  @Nullable
  public static <A extends Annotation> A getAnnotation​(Method method,
                                                       Class<A> annotationType)

  Get a single Annotation of annotationType from the supplied Method, where the annotation is either present or meta-present on the method.

  Correctly handles bridge Methods generated by the compiler.

  Note that this method supports only a single level of meta-annotations. For support for arbitrary levels of meta-annotations, use findAnnotation(Method, Class) instead.

  参数:

  method - the method to look for annotations on

  annotationType - the annotation type to look for

  返回:

  the first matching annotation, or null if not found

  另请参阅:

  BridgeMethodResolver.findBridgedMethod(Method), getAnnotation(AnnotatedElement, Class)

• getAnnotations

  @Deprecated
  @Nullable
  public static Annotation[] getAnnotations​(AnnotatedElement annotatedElement)

  已过时。

  as of 5.2 since it is superseded by the MergedAnnotations API
  Get all Annotations that are present on the supplied AnnotatedElement.

  Meta-annotations will not be searched.

  参数:

  annotatedElement - the Method, Constructor or Field to retrieve annotations from

  返回:

  the annotations found, an empty array, or null if not resolvable (e.g. because nested Class values in annotation attributes failed to resolve at runtime)

  从以下版本开始:

  4.0.8

  另请参阅:

  AnnotatedElement.getAnnotations()

• getAnnotations

  @Deprecated
  @Nullable
  public static Annotation[] getAnnotations​(Method method)

  已过时。

  as of 5.2 since it is superseded by the MergedAnnotations API
  Get all Annotations that are present on the supplied Method.

  Correctly handles bridge Methods generated by the compiler.

  Meta-annotations will not be searched.

  参数:

  method - the Method to retrieve annotations from

  返回:

  the annotations found, an empty array, or null if not resolvable (e.g. because nested Class values in annotation attributes failed to resolve at runtime)

  另请参阅:

  BridgeMethodResolver.findBridgedMethod(Method), AnnotatedElement.getAnnotations()

• getRepeatableAnnotations

  @Deprecated
  public static <A extends Annotation> Set<A> getRepeatableAnnotations​(AnnotatedElement annotatedElement,
                                                                       Class<A> annotationType)

  已过时。

  as of 5.2 since it is superseded by the MergedAnnotations API
  Get the repeatableannotations of annotationType from the supplied AnnotatedElement, where such annotations are either present, indirectly present, or meta-present on the element.

  This method mimics the functionality of Java 8's AnnotatedElement.getAnnotationsByType(Class) with support for automatic detection of a container annotation declared via @Repeatable (when running on Java 8 or higher) and with additional support for meta-annotations.

  Handles both single annotations and annotations nested within a container annotation.

  Correctly handles bridge methods generated by the compiler if the supplied element is a Method.

  Meta-annotations will be searched if the annotation is not present on the supplied element.

  参数:

  annotatedElement - the element to look for annotations on

  annotationType - the annotation type to look for

  返回:

  the annotations found or an empty set (never null)

  从以下版本开始:

  4.2

  另请参阅:

  getRepeatableAnnotations(AnnotatedElement, Class, Class), getDeclaredRepeatableAnnotations(AnnotatedElement, Class, Class), AnnotatedElementUtils.getMergedRepeatableAnnotations(AnnotatedElement, Class), BridgeMethodResolver.findBridgedMethod(java.lang.reflect.Method), Repeatable, AnnotatedElement.getAnnotationsByType(java.lang.Class<T>)

• getRepeatableAnnotations

  @Deprecated
  public static <A extends Annotation> Set<A> getRepeatableAnnotations​(AnnotatedElement annotatedElement,
                                                                       Class<A> annotationType,
                                                                       @Nullable
                                                                       Class<? extends Annotation> containerAnnotationType)

  已过时。

  as of 5.2 since it is superseded by the MergedAnnotations API
  Get the repeatableannotations of annotationType from the supplied AnnotatedElement, where such annotations are either present, indirectly present, or meta-present on the element.

  This method mimics the functionality of Java 8's AnnotatedElement.getAnnotationsByType(Class) with additional support for meta-annotations.

  Handles both single annotations and annotations nested within a container annotation.

  Correctly handles bridge methods generated by the compiler if the supplied element is a Method.

  Meta-annotations will be searched if the annotation is not present on the supplied element.

  参数:

  annotatedElement - the element to look for annotations on

  annotationType - the annotation type to look for

  containerAnnotationType - the type of the container that holds the annotations; may be null if a container is not supported or if it should be looked up via @Repeatable when running on Java 8 or higher

  返回:

  the annotations found or an empty set (never null)

  从以下版本开始:

  4.2

  另请参阅:

  getRepeatableAnnotations(AnnotatedElement, Class), getDeclaredRepeatableAnnotations(AnnotatedElement, Class), getDeclaredRepeatableAnnotations(AnnotatedElement, Class, Class), AnnotatedElementUtils.getMergedRepeatableAnnotations(AnnotatedElement, Class, Class), BridgeMethodResolver.findBridgedMethod(java.lang.reflect.Method), Repeatable, AnnotatedElement.getAnnotationsByType(java.lang.Class<T>)

• getDeclaredRepeatableAnnotations

  @Deprecated
  public static <A extends Annotation> Set<A> getDeclaredRepeatableAnnotations​(AnnotatedElement annotatedElement,
                                                                               Class<A> annotationType)

  已过时。

  as of 5.2 since it is superseded by the MergedAnnotations API
  Get the declared repeatableannotations of annotationType from the supplied AnnotatedElement, where such annotations are either directly present, indirectly present, or meta-present on the element.

  This method mimics the functionality of Java 8's AnnotatedElement.getDeclaredAnnotationsByType(Class) with support for automatic detection of a container annotation declared via @Repeatable (when running on Java 8 or higher) and with additional support for meta-annotations.

  Handles both single annotations and annotations nested within a container annotation.

  Correctly handles bridge methods generated by the compiler if the supplied element is a Method.

  Meta-annotations will be searched if the annotation is not present on the supplied element.

  参数:

  annotatedElement - the element to look for annotations on

  annotationType - the annotation type to look for

  返回:

  the annotations found or an empty set (never null)

  从以下版本开始:

  4.2

  另请参阅:

  getRepeatableAnnotations(AnnotatedElement, Class), getRepeatableAnnotations(AnnotatedElement, Class, Class), getDeclaredRepeatableAnnotations(AnnotatedElement, Class, Class), AnnotatedElementUtils.getMergedRepeatableAnnotations(AnnotatedElement, Class), BridgeMethodResolver.findBridgedMethod(java.lang.reflect.Method), Repeatable, AnnotatedElement.getDeclaredAnnotationsByType(java.lang.Class<T>)

• getDeclaredRepeatableAnnotations

  @Deprecated
  public static <A extends Annotation> Set<A> getDeclaredRepeatableAnnotations​(AnnotatedElement annotatedElement,
                                                                               Class<A> annotationType,
                                                                               @Nullable
                                                                               Class<? extends Annotation> containerAnnotationType)

  已过时。

  as of 5.2 since it is superseded by the MergedAnnotations API
  Get the declared repeatableannotations of annotationType from the supplied AnnotatedElement, where such annotations are either directly present, indirectly present, or meta-present on the element.

  This method mimics the functionality of Java 8's AnnotatedElement.getDeclaredAnnotationsByType(Class) with additional support for meta-annotations.

  Handles both single annotations and annotations nested within a container annotation.

  Correctly handles bridge methods generated by the compiler if the supplied element is a Method.

  Meta-annotations will be searched if the annotation is not present on the supplied element.

  参数:

  annotatedElement - the element to look for annotations on

  annotationType - the annotation type to look for

  containerAnnotationType - the type of the container that holds the annotations; may be null if a container is not supported or if it should be looked up via @Repeatable when running on Java 8 or higher

  返回:

  the annotations found or an empty set (never null)

  从以下版本开始:

  4.2

  另请参阅:

  getRepeatableAnnotations(AnnotatedElement, Class), getRepeatableAnnotations(AnnotatedElement, Class, Class), getDeclaredRepeatableAnnotations(AnnotatedElement, Class), AnnotatedElementUtils.getMergedRepeatableAnnotations(AnnotatedElement, Class, Class), BridgeMethodResolver.findBridgedMethod(java.lang.reflect.Method), Repeatable, AnnotatedElement.getDeclaredAnnotationsByType(java.lang.Class<T>)

• findAnnotation

  @Nullable
  public static <A extends Annotation> A findAnnotation​(AnnotatedElement annotatedElement,
                                                        @Nullable
                                                        Class<A> annotationType)

  Find a single Annotation of annotationType on the supplied AnnotatedElement.

  Meta-annotations will be searched if the annotation is not directly present on the supplied element.

  Warning: this method operates generically on annotated elements. In other words, this method does not execute specialized search algorithms for classes or methods. If you require the more specific semantics of findAnnotation(Class, Class) or findAnnotation(Method, Class), invoke one of those methods instead.

  参数:

  annotatedElement - the AnnotatedElement on which to find the annotation

  annotationType - the annotation type to look for, both locally and as a meta-annotation

  返回:

  the first matching annotation, or null if not found

  从以下版本开始:

  4.2

• findAnnotation

  @Nullable
  public static <A extends Annotation> A findAnnotation​(Method method,
                                                        @Nullable
                                                        Class<A> annotationType)

  Find a single Annotation of annotationType on the supplied Method, traversing its super methods (i.e. from superclasses and interfaces) if the annotation is not directly present on the given method itself.

  Correctly handles bridge Methods generated by the compiler.

  Meta-annotations will be searched if the annotation is not directly present on the method.

  Annotations on methods are not inherited by default, so we need to handle this explicitly.

  参数:

  method - the method to look for annotations on

  annotationType - the annotation type to look for

  返回:

  the first matching annotation, or null if not found

  另请参阅:

  getAnnotation(Method, Class)

• findAnnotation

  @Nullable
  public static <A extends Annotation> A findAnnotation​(Class<?> clazz,
                                                        @Nullable
                                                        Class<A> annotationType)

  Find a single Annotation of annotationType on the supplied Class, traversing its interfaces, annotations, and superclasses if the annotation is not directly present on the given class itself.

  This method explicitly handles class-level annotations which are not declared as inheritedas well as meta-annotations and annotations on interfaces.

  The algorithm operates as follows:

  1. Search for the annotation on the given class and return it if found.
  2. Recursively search through all annotations that the given class declares.
  3. Recursively search through all interfaces that the given class declares.
  4. Recursively search through the superclass hierarchy of the given class.

  Note: in this context, the term recursively means that the search process continues by returning to step #1 with the current interface, annotation, or superclass as the class to look for annotations on.

  参数:

  clazz - the class to look for annotations on

  annotationType - the type of annotation to look for

  返回:

  the first matching annotation, or null if not found

• findAnnotationDeclaringClass

  @Deprecated
  @Nullable
  public static Class<?> findAnnotationDeclaringClass​(Class<? extends Annotation> annotationType,
                                                      @Nullable
                                                      Class<?> clazz)

  已过时。

  as of 5.2 since it is superseded by the MergedAnnotations API
  Find the first Class in the inheritance hierarchy of the specified clazz (including the specified clazz itself) on which an annotation of the specified annotationType is directly present.

  If the supplied clazz is an interface, only the interface itself will be checked; the inheritance hierarchy for interfaces will not be traversed.

  Meta-annotations will not be searched.

  The standard Class API does not provide a mechanism for determining which class in an inheritance hierarchy actually declares an Annotation, so we need to handle this explicitly.

  参数:

  annotationType - the annotation type to look for

  clazz - the class to check for the annotation on (may be null)

  返回:

  the first Class in the inheritance hierarchy that declares an annotation of the specified annotationType, or null if not found

  另请参阅:

  Class.isAnnotationPresent(Class), Class.getDeclaredAnnotations()

• findAnnotationDeclaringClassForTypes

  @Deprecated
  @Nullable
  public static Class<?> findAnnotationDeclaringClassForTypes​(List<Class<? extends Annotation>> annotationTypes,
                                                              @Nullable
                                                              Class<?> clazz)

  已过时。

  as of 5.2 since it is superseded by the MergedAnnotations API
  Find the first Class in the inheritance hierarchy of the specified clazz (including the specified clazz itself) on which at least one of the specified annotationTypes is directly present.

  If the supplied clazz is an interface, only the interface itself will be checked; the inheritance hierarchy for interfaces will not be traversed.

  Meta-annotations will not be searched.

  The standard Class API does not provide a mechanism for determining which class in an inheritance hierarchy actually declares one of several candidate annotations, so we need to handle this explicitly.

  参数:

  annotationTypes - the annotation types to look for

  clazz - the class to check for the annotation on (may be null)

  返回:

  the first Class in the inheritance hierarchy that declares an annotation of at least one of the specified annotationTypes, or null if not found

  从以下版本开始:

  3.2.2

  另请参阅:

  Class.isAnnotationPresent(Class), Class.getDeclaredAnnotations()

• isAnnotationDeclaredLocally

  public static boolean isAnnotationDeclaredLocally​(Class<? extends Annotation> annotationType,
                                                    Class<?> clazz)

  Determine whether an annotation of the specified annotationType is declared locally (i.e. directly present) on the supplied clazz.

  The supplied Class may represent any type.

  Meta-annotations will not be searched.

  Note: This method does not determine if the annotation is inherited.

  参数:

  annotationType - the annotation type to look for

  clazz - the class to check for the annotation on

  返回:

  true if an annotation of the specified annotationType is directly present

  另请参阅:

  Class.getDeclaredAnnotations(), Class.getDeclaredAnnotation(Class)

• isAnnotationInherited

  @Deprecated
  public static boolean isAnnotationInherited​(Class<? extends Annotation> annotationType,
                                              Class<?> clazz)

  已过时。

  as of 5.2 since it is superseded by the MergedAnnotations API
  Determine whether an annotation of the specified annotationType is present on the supplied clazz and is inherited (i.e. not directly present).

  Meta-annotations will not be searched.

  If the supplied clazz is an interface, only the interface itself will be checked. In accordance with standard meta-annotation semantics in Java, the inheritance hierarchy for interfaces will not be traversed. See the javadoc for the @Inherited meta-annotation for further details regarding annotation inheritance.

  参数:

  annotationType - the annotation type to look for

  clazz - the class to check for the annotation on

  返回:

  true if an annotation of the specified annotationType is present and inherited

  另请参阅:

  Class.isAnnotationPresent(Class), isAnnotationDeclaredLocally(Class, Class)

• isAnnotationMetaPresent

  @Deprecated
  public static boolean isAnnotationMetaPresent​(Class<? extends Annotation> annotationType,
                                                @Nullable
                                                Class<? extends Annotation> metaAnnotationType)

  已过时。

  as of 5.2 since it is superseded by the MergedAnnotations API
  Determine if an annotation of type metaAnnotationType is meta-present on the supplied annotationType.

  参数:

  annotationType - the annotation type to search on

  metaAnnotationType - the type of meta-annotation to search for

  返回:

  true if such an annotation is meta-present

  从以下版本开始:

  4.2.1

• isInJavaLangAnnotationPackage

  public static boolean isInJavaLangAnnotationPackage​(@Nullable
                                                      Annotation annotation)

  Determine if the supplied Annotation is defined in the core JDK java.lang.annotation package.

  参数:

  annotation - the annotation to check

  返回:

  true if the annotation is in the java.lang.annotation package

• isInJavaLangAnnotationPackage

  public static boolean isInJavaLangAnnotationPackage​(@Nullable
                                                      String annotationType)

  Determine if the Annotation with the supplied name is defined in the core JDK java.lang.annotation package.

  参数:

  annotationType - the name of the annotation type to check

  返回:

  true if the annotation is in the java.lang.annotation package

  从以下版本开始:

  4.2

• validateAnnotation

  public static void validateAnnotation​(Annotation annotation)

  Check the declared attributes of the given annotation, in particular covering Google App Engine's late arrival of TypeNotPresentExceptionProxy for Class values (instead of early Class.getAnnotations() failure.

  This method not failing indicates that getAnnotationAttributes(Annotation) won't failure either (when attempted later on).

  参数:

  annotation - the annotation to validate

  抛出:

  IllegalStateException - if a declared Class attribute could not be read

  从以下版本开始:

  4.3.15

  另请参阅:

  Class.getAnnotations(), getAnnotationAttributes(Annotation)

• getAnnotationAttributes

  public static Map<String,​Object> getAnnotationAttributes​(Annotation annotation)

  Retrieve the given annotation's attributes as a Map, preserving all attribute types.

  Equivalent to calling getAnnotationAttributes(Annotation, boolean, boolean) with the classValuesAsString and nestedAnnotationsAsMap parameters set to false.

  Note: This method actually returns an AnnotationAttributes instance. However, the Map signature has been preserved for binary compatibility.

  参数:

  annotation - the annotation to retrieve the attributes for

  返回:

  the Map of annotation attributes, with attribute names as keys and corresponding attribute values as values (never null)

  另请参阅:

  getAnnotationAttributes(AnnotatedElement, Annotation), getAnnotationAttributes(Annotation, boolean, boolean), getAnnotationAttributes(AnnotatedElement, Annotation, boolean, boolean)

• getAnnotationAttributes

  public static Map<String,​Object> getAnnotationAttributes​(Annotation annotation,
                                                                 boolean classValuesAsString)

  Retrieve the given annotation's attributes as a Map.

  Equivalent to calling getAnnotationAttributes(Annotation, boolean, boolean) with the nestedAnnotationsAsMap parameter set to false.

  Note: This method actually returns an AnnotationAttributes instance. However, the Map signature has been preserved for binary compatibility.

  参数:

  annotation - the annotation to retrieve the attributes for

  classValuesAsString - whether to convert Class references into Strings (for compatibility with AnnotationMetadata) or to preserve them as Class references

  返回:

  the Map of annotation attributes, with attribute names as keys and corresponding attribute values as values (never null)

  另请参阅:

  getAnnotationAttributes(Annotation, boolean, boolean)

• getAnnotationAttributes

  public static AnnotationAttributes getAnnotationAttributes​(Annotation annotation,
                                                             boolean classValuesAsString,
                                                             boolean nestedAnnotationsAsMap)

  Retrieve the given annotation's attributes as an AnnotationAttributes map.

  This method provides fully recursive annotation reading capabilities on par with the reflection-based StandardAnnotationMetadata.

  参数:

  annotation - the annotation to retrieve the attributes for

  classValuesAsString - whether to convert Class references into Strings (for compatibility with AnnotationMetadata) or to preserve them as Class references

  nestedAnnotationsAsMap - whether to convert nested annotations into AnnotationAttributes maps (for compatibility with AnnotationMetadata) or to preserve them as Annotation instances

  返回:

  the annotation attributes (a specialized Map) with attribute names as keys and corresponding attribute values as values (never null)

  从以下版本开始:

  3.1.1

• getAnnotationAttributes

  public static AnnotationAttributes getAnnotationAttributes​(@Nullable
                                                             AnnotatedElement annotatedElement,
                                                             Annotation annotation)

  Retrieve the given annotation's attributes as an AnnotationAttributes map.

  Equivalent to calling getAnnotationAttributes(AnnotatedElement, Annotation, boolean, boolean) with the classValuesAsString and nestedAnnotationsAsMap parameters set to false.

  参数:

  annotatedElement - the element that is annotated with the supplied annotation; may be null if unknown

  annotation - the annotation to retrieve the attributes for

  返回:

  the annotation attributes (a specialized Map) with attribute names as keys and corresponding attribute values as values (never null)

  从以下版本开始:

  4.2

  另请参阅:

  getAnnotationAttributes(AnnotatedElement, Annotation, boolean, boolean)

• getAnnotationAttributes

  public static AnnotationAttributes getAnnotationAttributes​(@Nullable
                                                             AnnotatedElement annotatedElement,
                                                             Annotation annotation,
                                                             boolean classValuesAsString,
                                                             boolean nestedAnnotationsAsMap)

  Retrieve the given annotation's attributes as an AnnotationAttributes map.

  This method provides fully recursive annotation reading capabilities on par with the reflection-based StandardAnnotationMetadata.

  参数:

  annotatedElement - the element that is annotated with the supplied annotation; may be null if unknown

  annotation - the annotation to retrieve the attributes for

  classValuesAsString - whether to convert Class references into Strings (for compatibility with AnnotationMetadata) or to preserve them as Class references

  nestedAnnotationsAsMap - whether to convert nested annotations into AnnotationAttributes maps (for compatibility with AnnotationMetadata) or to preserve them as Annotation instances

  返回:

  the annotation attributes (a specialized Map) with attribute names as keys and corresponding attribute values as values (never null)

  从以下版本开始:

  4.2

• registerDefaultValues

  public static void registerDefaultValues​(AnnotationAttributes attributes)

  Register the annotation-declared default values for the given attributes, if available.

  参数:

  attributes - the annotation attributes to process

  从以下版本开始:

  4.3.2

• postProcessAnnotationAttributes

  public static void postProcessAnnotationAttributes​(@Nullable
                                                     Object annotatedElement,
                                                     @Nullable
                                                     AnnotationAttributes attributes,
                                                     boolean classValuesAsString)

  Post-process the supplied AnnotationAttributes, preserving nested annotations as Annotation instances.

  Specifically, this method enforces attribute alias semantics for annotation attributes that are annotated with @AliasFor and replaces default value placeholders with their original default values.

  参数:

  annotatedElement - the element that is annotated with an annotation or annotation hierarchy from which the supplied attributes were created; may be null if unknown

  attributes - the annotation attributes to post-process

  classValuesAsString - whether to convert Class references into Strings (for compatibility with AnnotationMetadata) or to preserve them as Class references

  从以下版本开始:

  4.3.2

  另请参阅:

  getDefaultValue(Class, String)

• getValue

  @Nullable
  public static Object getValue​(Annotation annotation)

  Retrieve the value of the value attribute of a single-element Annotation, given an annotation instance.

  参数:

  annotation - the annotation instance from which to retrieve the value

  返回:

  the attribute value, or null if not found unless the attribute value cannot be retrieved due to an AnnotationConfigurationException, in which case such an exception will be rethrown

  另请参阅:

  getValue(Annotation, String)

• getValue

  @Nullable
  public static Object getValue​(@Nullable
                                Annotation annotation,
                                @Nullable
                                String attributeName)

  Retrieve the value of a named attribute, given an annotation instance.

  参数:

  annotation - the annotation instance from which to retrieve the value

  attributeName - the name of the attribute value to retrieve

  返回:

  the attribute value, or null if not found unless the attribute value cannot be retrieved due to an AnnotationConfigurationException, in which case such an exception will be rethrown

  另请参阅:

  getValue(Annotation)

• getDefaultValue

  @Nullable
  public static Object getDefaultValue​(Annotation annotation)

  Retrieve the default value of the value attribute of a single-element Annotation, given an annotation instance.

  参数:

  annotation - the annotation instance from which to retrieve the default value

  返回:

  the default value, or null if not found

  另请参阅:

  getDefaultValue(Annotation, String)

• getDefaultValue

  @Nullable
  public static Object getDefaultValue​(@Nullable
                                       Annotation annotation,
                                       @Nullable
                                       String attributeName)

  Retrieve the default value of a named attribute, given an annotation instance.

  参数:

  annotation - the annotation instance from which to retrieve the default value

  attributeName - the name of the attribute value to retrieve

  返回:

  the default value of the named attribute, or null if not found

  另请参阅:

  getDefaultValue(Class, String)

• getDefaultValue

  @Nullable
  public static Object getDefaultValue​(Class<? extends Annotation> annotationType)

  Retrieve the default value of the value attribute of a single-element Annotation, given the annotation type.

  参数:

  annotationType - the annotation type for which the default value should be retrieved

  返回:

  the default value, or null if not found

  另请参阅:

  getDefaultValue(Class, String)

• getDefaultValue

  @Nullable
  public static Object getDefaultValue​(@Nullable
                                       Class<? extends Annotation> annotationType,
                                       @Nullable
                                       String attributeName)

  Retrieve the default value of a named attribute, given the annotation type.

  参数:

  annotationType - the annotation type for which the default value should be retrieved

  attributeName - the name of the attribute value to retrieve.

  返回:

  the default value of the named attribute, or null if not found

  另请参阅:

  getDefaultValue(Annotation, String)

• synthesizeAnnotation

  public static <A extends Annotation> A synthesizeAnnotation​(A annotation,
                                                              @Nullable
                                                              AnnotatedElement annotatedElement)

  Synthesize an annotation from the supplied annotation by wrapping it in a dynamic proxy that transparently enforces attribute alias semantics for annotation attributes that are annotated with @AliasFor.

  参数:

  annotation - the annotation to synthesize

  annotatedElement - the element that is annotated with the supplied annotation; may be null if unknown

  返回:

  the synthesized annotation if the supplied annotation is synthesizable; null if the supplied annotation is null; otherwise the supplied annotation unmodified

  抛出:

  AnnotationConfigurationException - if invalid configuration of @AliasFor is detected

  从以下版本开始:

  4.2

  另请参阅:

  synthesizeAnnotation(Map, Class, AnnotatedElement), synthesizeAnnotation(Class)

• synthesizeAnnotation

  public static <A extends Annotation> A synthesizeAnnotation​(Class<A> annotationType)

  Synthesize an annotation from its default attributes values.

  This method simply delegates to synthesizeAnnotation(Map, Class, AnnotatedElement), supplying an empty map for the source attribute values and null for the AnnotatedElement.

  参数:

  annotationType - the type of annotation to synthesize

  返回:

  the synthesized annotation

  抛出:

  IllegalArgumentException - if a required attribute is missing

  AnnotationConfigurationException - if invalid configuration of @AliasFor is detected

  从以下版本开始:

  4.2

  另请参阅:

  synthesizeAnnotation(Map, Class, AnnotatedElement), synthesizeAnnotation(Annotation, AnnotatedElement)

• synthesizeAnnotation

  public static <A extends Annotation> A synthesizeAnnotation​(Map<String,​Object> attributes,
                                                              Class<A> annotationType,
                                                              @Nullable
                                                              AnnotatedElement annotatedElement)

  Synthesize an annotation from the supplied map of annotation attributes by wrapping the map in a dynamic proxy that implements an annotation of the specified annotationType and transparently enforces attribute alias semantics for annotation attributes that are annotated with @AliasFor.

  The supplied map must contain a key-value pair for every attribute defined in the supplied annotationType that is not aliased or does not have a default value. Nested maps and nested arrays of maps will be recursively synthesized into nested annotations or nested arrays of annotations, respectively.

  Note that AnnotationAttributes is a specialized type of Map that is an ideal candidate for this method's attributes argument.

  参数:

  attributes - the map of annotation attributes to synthesize

  annotationType - the type of annotation to synthesize

  annotatedElement - the element that is annotated with the annotation corresponding to the supplied attributes; may be null if unknown

  返回:

  the synthesized annotation

  抛出:

  IllegalArgumentException - if a required attribute is missing or if an attribute is not of the correct type

  AnnotationConfigurationException - if invalid configuration of @AliasFor is detected

  从以下版本开始:

  4.2

  另请参阅:

  synthesizeAnnotation(Annotation, AnnotatedElement), synthesizeAnnotation(Class), getAnnotationAttributes(AnnotatedElement, Annotation), getAnnotationAttributes(AnnotatedElement, Annotation, boolean, boolean)

• clearCache

  public static void clearCache()

  Clear the internal annotation metadata cache.

  从以下版本开始:

  4.3.15