org.springframework.core.annotation

Interface AnnotatedElementUtils.Processor<T>

Type Parameters:

T - the type of result returned by the processor

All Known Implementing Classes:

AnnotatedElementUtils.MergedAnnotationAttributesProcessor, AnnotatedElementUtils.SimpleAnnotationProcessor

Enclosing class:

AnnotatedElementUtils

private static interface AnnotatedElementUtils.Processor<T>

Callback interface that is used to process annotations during a search.

Depending on the use case, a processor may choose to process(java.lang.reflect.AnnotatedElement, java.lang.annotation.Annotation, int) a single target annotation, multiple target annotations, or all annotations discovered by the currently executing search. The term "target" in this context refers to a matching annotation (i.e., a specific annotation type that was found during the search). Returning a non-null value from the process(java.lang.reflect.AnnotatedElement, java.lang.annotation.Annotation, int) method instructs the search algorithm to stop searching further; whereas, returning null from the process(java.lang.reflect.AnnotatedElement, java.lang.annotation.Annotation, int) method instructs the search algorithm to continue searching for additional annotations.

Processors can optionally post-process the result of the process(java.lang.reflect.AnnotatedElement, java.lang.annotation.Annotation, int) method as the search algorithm goes back down the annotation hierarchy from an invocation of process(java.lang.reflect.AnnotatedElement, java.lang.annotation.Annotation, int) that returned a non-null value down to the AnnotatedElement that was supplied as the starting point to the search algorithm.

Method Summary

Modifier and Type	Method and Description
void	postProcess(java.lang.reflect.AnnotatedElement annotatedElement, java.lang.annotation.Annotation annotation, T result) Post-process the result returned by the process(java.lang.reflect.AnnotatedElement, java.lang.annotation.Annotation, int) method.
T	process(java.lang.reflect.AnnotatedElement annotatedElement, java.lang.annotation.Annotation annotation, int metaDepth) Process the supplied annotation.

Method Detail

process

T process(java.lang.reflect.AnnotatedElement annotatedElement,
          java.lang.annotation.Annotation annotation,
          int metaDepth)

Process the supplied annotation.

Depending on the use case, the supplied annotation may be an actual target annotation that has been found by the search algorithm, or it may be some other annotation within the annotation hierarchy. In the latter case, the metaDepth should have a value greater than 0. In any case, it is up to concrete implementations of this method to decide what to do with the supplied annotation.

The metaDepth parameter represents the depth of the annotation relative to the first annotated element in the annotation hierarchy. For example, an annotation that is present on a non-annotation element will have a depth of 0; a meta-annotation will have a depth of 1; and a meta-meta-annotation will have a depth of 2; etc.

Parameters:

annotatedElement - the element that is annotated with the supplied annotation, used for contextual logging; may be null if unknown

annotation - the annotation to process

metaDepth - the meta-depth of the annotation

Returns:

the result of the processing, or null to continue searching for additional annotations

postProcess

void postProcess(java.lang.reflect.AnnotatedElement annotatedElement,
                 java.lang.annotation.Annotation annotation,
                 T result)

Post-process the result returned by the process(java.lang.reflect.AnnotatedElement, java.lang.annotation.Annotation, int) method.

The annotation supplied to this method is an annotation that is present in the annotation hierarchy, between the initial AnnotatedElement and an invocation of process(java.lang.reflect.AnnotatedElement, java.lang.annotation.Annotation, int) that returned a non-null value.

Parameters:

annotatedElement - the element that is annotated with the supplied annotation, used for contextual logging; may be null if unknown

annotation - the annotation to post-process

result - the result to post-process