Minimize reflective interaction with annotation instances during retrieval

Issue: SPR-15387

Author: jhoeller

spring-core/src/main/java/org/springframework/core/annotation/AnnotatedElementUtils.java

@@ -427,10 +427,10 @@ public static <A extends Annotation> A getMergedAnnotation(AnnotatedElement elem
 	 * single annotation and within annotation hierarchies.
 	 * <p>This method follows <em>get semantics</em> as described in the
 	 * {@linkplain AnnotatedElementUtils class-level javadoc}.
-	 * @param element the annotated element; never {@code null}
-	 * @param annotationType the annotation type to find; never {@code null}
-	 * @return the set of all merged, synthesized {@code Annotations} found, or an empty
-	 * set if none were found
+	 * @param element the annotated element (never {@code null})
+	 * @param annotationType the annotation type to find (never {@code null})
+	 * @return the set of all merged, synthesized {@code Annotations} found,
+	 * or an empty set if none were found
 	 * @since 4.3
 	 * @see #getMergedAnnotation(AnnotatedElement, Class)
 	 * @see #getAllAnnotationAttributes(AnnotatedElement, String)
@@ -460,10 +460,10 @@ public static <A extends Annotation> Set<A> getAllMergedAnnotations(AnnotatedEle
 	 * single annotation and within annotation hierarchies.
 	 * <p>This method follows <em>get semantics</em> as described in the
 	 * {@linkplain AnnotatedElementUtils class-level javadoc}.
-	 * @param element the annotated element; never {@code null}
-	 * @param annotationType the annotation type to find; never {@code null}
-	 * @return the set of all merged repeatable {@code Annotations} found, or an empty
-	 * set if none were found
+	 * @param element the annotated element (never {@code null})
+	 * @param annotationType the annotation type to find (never {@code null})
+	 * @return the set of all merged repeatable {@code Annotations} found,
+	 * or an empty set if none were found
 	 * @since 4.3
 	 * @see #getMergedAnnotation(AnnotatedElement, Class)
 	 * @see #getAllMergedAnnotations(AnnotatedElement, Class)
@@ -488,13 +488,13 @@ public static <A extends Annotation> Set<A> getMergedRepeatableAnnotations(Annot
 	 * single annotation and within annotation hierarchies.
 	 * <p>This method follows <em>get semantics</em> as described in the
 	 * {@linkplain AnnotatedElementUtils class-level javadoc}.
-	 * @param element the annotated element; never {@code null}
-	 * @param annotationType the annotation type to find; never {@code null}
+	 * @param element the annotated element (never {@code null})
+	 * @param annotationType the annotation type to find (never {@code null})
 	 * @param containerType the type of the container that holds the annotations;
 	 * may be {@code null} if the container type should be looked up via
 	 * {@link java.lang.annotation.Repeatable}
-	 * @return the set of all merged repeatable {@code Annotations} found, or an empty
-	 * set if none were found
+	 * @return the set of all merged repeatable {@code Annotations} found,
+	 * or an empty set if none were found
 	 * @since 4.3
 	 * @see #getMergedAnnotation(AnnotatedElement, Class)
 	 * @see #getAllMergedAnnotations(AnnotatedElement, Class)
@@ -724,10 +724,10 @@ public static <A extends Annotation> A findMergedAnnotation(AnnotatedElement ele
 	 * single annotation and within annotation hierarchies.
 	 * <p>This method follows <em>find semantics</em> as described in the
 	 * {@linkplain AnnotatedElementUtils class-level javadoc}.
-	 * @param element the annotated element; never {@code null}
-	 * @param annotationType the annotation type to find; never {@code null}
-	 * @return the set of all merged, synthesized {@code Annotations} found, or an empty
-	 * set if none were found
+	 * @param element the annotated element (never {@code null})
+	 * @param annotationType the annotation type to find (never {@code null})
+	 * @return the set of all merged, synthesized {@code Annotations} found,
+	 * or an empty set if none were found
 	 * @since 4.3
 	 * @see #findMergedAnnotation(AnnotatedElement, Class)
 	 * @see #getAllMergedAnnotations(AnnotatedElement, Class)
@@ -756,10 +756,10 @@ public static <A extends Annotation> Set<A> findAllMergedAnnotations(AnnotatedEl
 	 * single annotation and within annotation hierarchies.
 	 * <p>This method follows <em>find semantics</em> as described in the
 	 * {@linkplain AnnotatedElementUtils class-level javadoc}.
-	 * @param element the annotated element; never {@code null}
-	 * @param annotationType the annotation type to find; never {@code null}
-	 * @return the set of all merged repeatable {@code Annotations} found, or an empty
-	 * set if none were found
+	 * @param element the annotated element (never {@code null})
+	 * @param annotationType the annotation type to find (never {@code null})
+	 * @return the set of all merged repeatable {@code Annotations} found,
+	 * or an empty set if none were found
 	 * @since 4.3
 	 * @see #findMergedAnnotation(AnnotatedElement, Class)
 	 * @see #findAllMergedAnnotations(AnnotatedElement, Class)
@@ -784,13 +784,13 @@ public static <A extends Annotation> Set<A> findMergedRepeatableAnnotations(Anno
 	 * single annotation and within annotation hierarchies.
 	 * <p>This method follows <em>find semantics</em> as described in the
 	 * {@linkplain AnnotatedElementUtils class-level javadoc}.
-	 * @param element the annotated element; never {@code null}
-	 * @param annotationType the annotation type to find; never {@code null}
+	 * @param element the annotated element (never {@code null})
+	 * @param annotationType the annotation type to find (never {@code null})
 	 * @param containerType the type of the container that holds the annotations;
 	 * may be {@code null} if the container type should be looked up via
 	 * {@link java.lang.annotation.Repeatable}
-	 * @return the set of all merged repeatable {@code Annotations} found, or an empty
-	 * set if none were found
+	 * @return the set of all merged repeatable {@code Annotations} found,
+	 * or an empty set if none were found
 	 * @since 4.3
 	 * @see #findMergedAnnotation(AnnotatedElement, Class)
 	 * @see #findAllMergedAnnotations(AnnotatedElement, Class)
@@ -947,9 +947,10 @@ private static <T> T searchWithGetSemanticsInAnnotations(AnnotatedElement elemen
 
 		// Search in annotations
 		for (Annotation annotation : annotations) {
-			if (!AnnotationUtils.isInJavaLangAnnotationPackage(annotation)) {
-				if (annotation.annotationType() == annotationType ||
-						annotation.annotationType().getName().equals(annotationName) ||
+			Class<? extends Annotation> currentAnnotationType = annotation.annotationType();
+			if (!AnnotationUtils.isInJavaLangAnnotationPackage(currentAnnotationType)) {
+				if (currentAnnotationType == annotationType ||
+						currentAnnotationType.getName().equals(annotationName) ||
 						processor.alwaysProcesses()) {
 					T result = processor.process(element, annotation, metaDepth);
 					if (result != null) {
@@ -962,7 +963,7 @@ private static <T> T searchWithGetSemanticsInAnnotations(AnnotatedElement elemen
 					}
 				}
 				// Repeatable annotations in container?
-				else if (annotation.annotationType() == containerType) {
+				else if (currentAnnotationType == containerType) {
 					for (Annotation contained : getRawAnnotationsFromContainer(element, annotation)) {
 						T result = processor.process(element, contained, metaDepth);
 						if (result != null) {
@@ -977,8 +978,9 @@ else if (annotation.annotationType() == containerType) {
 
 		// Recursively search in meta-annotations
 		for (Annotation annotation : annotations) {
-			if (!AnnotationUtils.isInJavaLangAnnotationPackage(annotation)) {
-				T result = searchWithGetSemantics(annotation.annotationType(), annotationType,
+			Class<? extends Annotation> currentAnnotationType = annotation.annotationType();
+			if (!AnnotationUtils.isInJavaLangAnnotationPackage(currentAnnotationType)) {
+				T result = searchWithGetSemantics(currentAnnotationType, annotationType,
 						annotationName, containerType, processor, visited, metaDepth + 1);
 				if (result != null) {
 					processor.postProcess(element, annotation, result);
@@ -1051,7 +1053,7 @@ private static <T> T searchWithFindSemantics(AnnotatedElement element, Class<? e
 	 * have already been <em>visited</em>.
 	 * <p>The {@code metaDepth} parameter is explained in the
 	 * {@link Processor#process process()} method of the {@link Processor} API.
-	 * @param element the annotated element; never {@code null}
+	 * @param element the annotated element (never {@code null})
 	 * @param annotationType the annotation type to find
 	 * @param annotationName the fully qualified class name of the annotation
 	 * type to find (as an alternative to {@code annotationType})
@@ -1077,11 +1079,11 @@ private static <T> T searchWithFindSemantics(AnnotatedElement element, Class<? e
 
 				// Search in local annotations
 				for (Annotation annotation : annotations) {
-					if (!AnnotationUtils.isInJavaLangAnnotationPackage(annotation)) {
-						if (annotation.annotationType() == annotationType
-								|| annotation.annotationType().getName().equals(annotationName)
-								|| processor.alwaysProcesses()) {
-
+					Class<? extends Annotation> currentAnnotationType = annotation.annotationType();
+					if (!AnnotationUtils.isInJavaLangAnnotationPackage(currentAnnotationType)) {
+						if (currentAnnotationType == annotationType ||
+								currentAnnotationType.getName().equals(annotationName) ||
+								processor.alwaysProcesses()) {
 							T result = processor.process(element, annotation, metaDepth);
 							if (result != null) {
 								if (processor.aggregates() && metaDepth == 0) {
@@ -1093,7 +1095,7 @@ private static <T> T searchWithFindSemantics(AnnotatedElement element, Class<? e
 							}
 						}
 						// Repeatable annotations in container?
-						else if (annotation.annotationType() == containerType) {
+						else if (currentAnnotationType == containerType) {
 							for (Annotation contained : getRawAnnotationsFromContainer(element, annotation)) {
 								T result = processor.process(element, contained, metaDepth);
 								if (result != null) {
@@ -1108,11 +1110,12 @@ else if (annotation.annotationType() == containerType) {
 
 				// Search in meta annotations on local annotations
 				for (Annotation annotation : annotations) {
-					if (!AnnotationUtils.isInJavaLangAnnotationPackage(annotation)) {
-						T result = searchWithFindSemantics(annotation.annotationType(), annotationType, annotationName,
+					Class<? extends Annotation> currentAnnotationType = annotation.annotationType();
+					if (!AnnotationUtils.isInJavaLangAnnotationPackage(currentAnnotationType)) {
+						T result = searchWithFindSemantics(currentAnnotationType, annotationType, annotationName,
 								containerType, processor, visited, metaDepth + 1);
 						if (result != null) {
-							processor.postProcess(annotation.annotationType(), annotation, result);
+							processor.postProcess(currentAnnotationType, annotation, result);
 							if (processor.aggregates() && metaDepth == 0) {
 								aggregatedResults.add(result);
 							}
@@ -1252,7 +1255,7 @@ private static <A extends Annotation> A[] getRawAnnotationsFromContainer(Annotat
 	 * Resolve the container type for the supplied repeatable {@code annotationType}.
 	 * <p>Delegates to {@link AnnotationUtils#resolveContainerAnnotationType(Class)}.
 	 * @param annotationType the annotation type to resolve the container for
-	 * @return the container type; never {@code null}
+	 * @return the container type (never {@code null})
 	 * @throws IllegalArgumentException if the container type cannot be resolved
 	 * @since 4.3
 	 */
@@ -1403,8 +1406,8 @@ private interface Processor<T> {
 		 * responsible for asking this processor if it {@link #aggregates} results
 		 * and then adding the post-processed results to the list returned by this
 		 * method.
-		 * @return the list of results aggregated by this processor; never
-		 * {@code null} unless {@link #aggregates} returns {@code false}
+		 * @return the list of results aggregated by this processor
+		 * (never {@code null} unless {@link #aggregates} returns {@code false})
 		 * @see #aggregates
 		 * @since 4.3
 		 */

spring-core/src/main/java/org/springframework/core/annotation/AnnotationUtils.java

@@ -64,7 +64,7 @@
  * <h3>Terminology</h3>
  * The terms <em>directly present</em>, <em>indirectly present</em>, and
  * <em>present</em> have the same meanings as defined in the class-level
- * Javadoc for {@link AnnotatedElement} (in Java 8).
+ * javadoc for {@link AnnotatedElement} (in Java 8).
  *
  * <p>An annotation is <em>meta-present</em> on an element if the annotation
  * is declared as a meta-annotation on some other annotation which is
@@ -492,9 +492,10 @@ private static <A extends Annotation> A findAnnotation(
 			if (annotation != null) {
 				return annotation;
 			}
-			for (Annotation ann : annotatedElement.getDeclaredAnnotations()) {
-				if (!isInJavaLangAnnotationPackage(ann) && visited.add(ann)) {
-					annotation = findAnnotation((AnnotatedElement) ann.annotationType(), annotationType, visited);
+			for (Annotation declaredAnn : annotatedElement.getDeclaredAnnotations()) {
+				Class<? extends Annotation> declaredType = declaredAnn.annotationType();
+				if (!isInJavaLangAnnotationPackage(declaredType) && visited.add(declaredAnn)) {
+					annotation = findAnnotation((AnnotatedElement) declaredType, annotationType, visited);
 					if (annotation != null) {
 						return annotation;
 					}
@@ -679,9 +680,10 @@ private static <A extends Annotation> A findAnnotation(Class<?> clazz, Class<A>
 			if (annotation != null) {
 				return annotation;
 			}
-			for (Annotation ann : clazz.getDeclaredAnnotations()) {
-				if (!isInJavaLangAnnotationPackage(ann) && visited.add(ann)) {
-					annotation = findAnnotation(ann.annotationType(), annotationType, visited);
+			for (Annotation declaredAnn : clazz.getDeclaredAnnotations()) {
+				Class<? extends Annotation> declaredType = declaredAnn.annotationType();
+				if (!isInJavaLangAnnotationPackage(declaredType) && visited.add(declaredAnn)) {
+					annotation = findAnnotation(declaredType, annotationType, visited);
 					if (annotation != null) {
 						return annotation;
 					}
@@ -816,7 +818,7 @@ public static boolean isAnnotationDeclaredLocally(Class<? extends Annotation> an
 	 * <p>If the supplied {@code 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 {@linkplain java.lang.annotation.Inherited Javadoc}
+	 * be traversed. See the {@linkplain java.lang.annotation.Inherited javadoc}
 	 * for the {@code @Inherited} meta-annotation for further details regarding
 	 * annotation inheritance.
 	 * @param annotationType the annotation type to look for
@@ -868,13 +870,24 @@ public static boolean isAnnotationMetaPresent(Class<? extends Annotation> annota
 	 * @return {@code true} if the annotation is in the {@code java.lang.annotation} package
 	 */
 	public static boolean isInJavaLangAnnotationPackage(Annotation annotation) {
-		return (annotation != null && isInJavaLangAnnotationPackage(annotation.annotationType().getName()));
+		return (annotation != null && isInJavaLangAnnotationPackage(annotation.annotationType()));
 	}
 
 	/**
 	 * Determine if the {@link Annotation} with the supplied name is defined
 	 * in the core JDK {@code java.lang.annotation} package.
-	 * @param annotationType the name of the annotation type to check (never {@code null} or empty)
+	 * @param annotationType the annotation type to check
+	 * @return {@code true} if the annotation is in the {@code java.lang.annotation} package
+	 * @since 4.3.8
+	 */
+	static boolean isInJavaLangAnnotationPackage(Class<? extends Annotation> annotationType) {
+		return (annotationType != null && isInJavaLangAnnotationPackage(annotationType.getName()));
+	}
+
+	/**
+	 * Determine if the {@link Annotation} with the supplied name is defined
+	 * in the core JDK {@code java.lang.annotation} package.
+	 * @param annotationType the name of the annotation type to check
 	 * @return {@code true} if the annotation is in the {@code java.lang.annotation} package
 	 * @since 4.2
 	 */
@@ -1519,8 +1532,8 @@ static Annotation[] synthesizeAnnotationArray(Annotation[] annotations, Object a
 	 * {@linkplain #synthesizeAnnotation(Map, Class, AnnotatedElement)
 	 * synthesized} versions of the maps from the input array.
 	 * @param maps the array of maps of annotation attributes to synthesize
-	 * @param annotationType the type of annotations to synthesize; never
-	 * {@code null}
+	 * @param annotationType the type of annotations to synthesize
+	 * (never {@code null})
 	 * @return a new array of synthesized annotations, or {@code null} if
 	 * the supplied array is {@code null}
 	 * @throws AnnotationConfigurationException if invalid configuration of
@@ -1668,8 +1681,8 @@ static List<String> getAttributeAliasNames(Method attribute) {
 	/**
 	 * Get the name of the overridden attribute configured via
 	 * {@link AliasFor @AliasFor} for the supplied annotation {@code attribute}.
-	 * @param attribute the attribute from which to retrieve the override;
-	 * never {@code null}
+	 * @param attribute the attribute from which to retrieve the override
+	 * (never {@code null})
 	 * @param metaAnnotationType the type of meta-annotation in which the
 	 * overridden attribute is allowed to be declared
 	 * @return the name of the overridden attribute, or {@code null} if not
@@ -1696,8 +1709,8 @@ static String getAttributeOverrideName(Method attribute, Class<? extends Annotat
 	 * match Java's requirements for annotation <em>attributes</em>.
 	 * <p>All methods in the returned list will be
 	 * {@linkplain ReflectionUtils#makeAccessible(Method) made accessible}.
-	 * @param annotationType the type in which to search for attribute methods;
-	 * never {@code null}
+	 * @param annotationType the type in which to search for attribute methods
+	 * (never {@code null})
 	 * @return all annotation attribute methods in the specified annotation
 	 * type (never {@code null}, though potentially <em>empty</em>)
 	 * @since 4.2
@@ -1906,7 +1919,7 @@ private void process(AnnotatedElement element) {
 						else if (ObjectUtils.nullSafeEquals(this.containerAnnotationType, currentAnnotationType)) {
 							this.result.addAll(getValue(element, ann));
 						}
-						else if (!isInJavaLangAnnotationPackage(ann)) {
+						else if (!isInJavaLangAnnotationPackage(currentAnnotationType)) {
 							process(currentAnnotationType);
 						}
 					}

spring-core/src/main/java/org/springframework/core/type/classreading/AnnotationAttributesReadingVisitor.java

@@ -92,17 +92,18 @@ public void visitEnd() {
 	}
 
 	private void recursivelyCollectMetaAnnotations(Set<Annotation> visited, Annotation annotation) {
-		if (!AnnotationUtils.isInJavaLangAnnotationPackage(annotation) && visited.add(annotation)) {
+		Class<? extends Annotation> annotationType = annotation.annotationType();
+		String annotationName = annotationType.getName();
+		if (!AnnotationUtils.isInJavaLangAnnotationPackage(annotationName) && visited.add(annotation)) {
 			try {
 				// Only do attribute scanning for public annotations; we'd run into
 				// IllegalAccessExceptions otherwise, and we don't want to mess with
 				// accessibility in a SecurityManager environment.
-				if (Modifier.isPublic(annotation.annotationType().getModifiers())) {
-					String annotationName = annotation.annotationType().getName();
+				if (Modifier.isPublic(annotationType.getModifiers())) {
 					this.attributesMap.add(annotationName,
 							AnnotationUtils.getAnnotationAttributes(annotation, false, true));
 				}
-				for (Annotation metaMetaAnnotation : annotation.annotationType().getAnnotations()) {
+				for (Annotation metaMetaAnnotation : annotationType.getAnnotations()) {
 					recursivelyCollectMetaAnnotations(visited, metaMetaAnnotation);
 				}
 			}