Avoid expensive annotation retrieval algorithm if no annotations present in the first place

Issue: SPR-13621

spring-beans/src/main/java/org/springframework/beans/factory/annotation/AutowiredAnnotationBeanPostProcessor.java

@@ -441,10 +441,12 @@ public class AutowiredAnnotationBeanPostProcessor extends InstantiationAwareBean
 	}
 
 	private AnnotationAttributes findAutowiredAnnotation(AccessibleObject ao) {
-		for (Class<? extends Annotation> type : this.autowiredAnnotationTypes) {
-			AnnotationAttributes attributes = AnnotatedElementUtils.getMergedAnnotationAttributes(ao, type);
-			if (attributes != null) {
-				return attributes;
+		if (ao.getAnnotations().length > 0) {
+			for (Class<? extends Annotation> type : this.autowiredAnnotationTypes) {
+				AnnotationAttributes attributes = AnnotatedElementUtils.getMergedAnnotationAttributes(ao, type);
+				if (attributes != null) {
+					return attributes;
+				}
 			}
 		}
 		return null;

spring-core/src/main/java/org/springframework/core/type/StandardAnnotationMetadata.java

@@ -38,6 +38,8 @@ import org.springframework.util.MultiValueMap;
  */
 public class StandardAnnotationMetadata extends StandardClassMetadata implements AnnotationMetadata {
 
+	private final Annotation[] annotations;
+
 	private final boolean nestedAnnotationsAsMap;
 
 
@@ -63,6 +65,7 @@ public class StandardAnnotationMetadata extends StandardClassMetadata implements
 	 */
 	public StandardAnnotationMetadata(Class<?> introspectedClass, boolean nestedAnnotationsAsMap) {
 		super(introspectedClass);
+		this.annotations = introspectedClass.getAnnotations();
 		this.nestedAnnotationsAsMap = nestedAnnotationsAsMap;
 	}
 
@@ -70,8 +73,7 @@ public class StandardAnnotationMetadata extends StandardClassMetadata implements
 	@Override
 	public Set<String> getAnnotationTypes() {
 		Set<String> types = new LinkedHashSet<String>();
-		Annotation[] anns = getIntrospectedClass().getAnnotations();
-		for (Annotation ann : anns) {
+		for (Annotation ann : this.annotations) {
 			types.add(ann.annotationType().getName());
 		}
 		return types;
@@ -79,13 +81,13 @@ public class StandardAnnotationMetadata extends StandardClassMetadata implements
 
 	@Override
 	public Set<String> getMetaAnnotationTypes(String annotationName) {
-		return AnnotatedElementUtils.getMetaAnnotationTypes(getIntrospectedClass(), annotationName);
+		return (this.annotations.length > 0 ?
+				AnnotatedElementUtils.getMetaAnnotationTypes(getIntrospectedClass(), annotationName) : null);
 	}
 
 	@Override
 	public boolean hasAnnotation(String annotationName) {
-		Annotation[] anns = getIntrospectedClass().getAnnotations();
-		for (Annotation ann : anns) {
+		for (Annotation ann : this.annotations) {
 			if (ann.annotationType().getName().equals(annotationName)) {
 				return true;
 			}
@@ -95,23 +97,25 @@ public class StandardAnnotationMetadata extends StandardClassMetadata implements
 
 	@Override
 	public boolean hasMetaAnnotation(String annotationName) {
-		return AnnotatedElementUtils.hasMetaAnnotationTypes(getIntrospectedClass(), annotationName);
+		return (this.annotations.length > 0 &&
+				AnnotatedElementUtils.hasMetaAnnotationTypes(getIntrospectedClass(), annotationName));
 	}
 
 	@Override
 	public boolean isAnnotated(String annotationName) {
-		return AnnotatedElementUtils.isAnnotated(getIntrospectedClass(), annotationName);
+		return (this.annotations.length > 0 &&
+				AnnotatedElementUtils.isAnnotated(getIntrospectedClass(), annotationName));
 	}
 
 	@Override
 	public Map<String, Object> getAnnotationAttributes(String annotationName) {
-		return this.getAnnotationAttributes(annotationName, false);
+		return getAnnotationAttributes(annotationName, false);
 	}
 
 	@Override
 	public Map<String, Object> getAnnotationAttributes(String annotationName, boolean classValuesAsString) {
-		return AnnotatedElementUtils.getMergedAnnotationAttributes(getIntrospectedClass(),
-				annotationName, classValuesAsString, this.nestedAnnotationsAsMap);
+		return (this.annotations.length > 0 ? AnnotatedElementUtils.getMergedAnnotationAttributes(
+				getIntrospectedClass(), annotationName, classValuesAsString, this.nestedAnnotationsAsMap) : null);
 	}
 
 	@Override
@@ -121,15 +125,16 @@ public class StandardAnnotationMetadata extends StandardClassMetadata implements
 
 	@Override
 	public MultiValueMap<String, Object> getAllAnnotationAttributes(String annotationName, boolean classValuesAsString) {
-		return AnnotatedElementUtils.getAllAnnotationAttributes(getIntrospectedClass(),
-				annotationName, classValuesAsString, this.nestedAnnotationsAsMap);
+		return (this.annotations.length > 0 ? AnnotatedElementUtils.getAllAnnotationAttributes(
+				getIntrospectedClass(), annotationName, classValuesAsString, this.nestedAnnotationsAsMap) : null);
 	}
 
 	@Override
 	public boolean hasAnnotatedMethods(String annotationName) {
 		Method[] methods = getIntrospectedClass().getDeclaredMethods();
 		for (Method method : methods) {
-			if (!method.isBridge() && AnnotatedElementUtils.isAnnotated(method, annotationName)) {
+			if (!method.isBridge() && method.getAnnotations().length > 0 &&
+					AnnotatedElementUtils.isAnnotated(method, annotationName)) {
 				return true;
 			}
 		}
@@ -141,7 +146,8 @@ public class StandardAnnotationMetadata extends StandardClassMetadata implements
 		Method[] methods = getIntrospectedClass().getDeclaredMethods();
 		Set<MethodMetadata> annotatedMethods = new LinkedHashSet<MethodMetadata>();
 		for (Method method : methods) {
-			if (!method.isBridge() && AnnotatedElementUtils.isAnnotated(method, annotationName)) {
+			if (!method.isBridge() && method.getAnnotations().length > 0 &&
+					AnnotatedElementUtils.isAnnotated(method, annotationName)) {
 				annotatedMethods.add(new StandardMethodMetadata(method, this.nestedAnnotationsAsMap));
 			}
 		}

spring-tx/src/main/java/org/springframework/transaction/annotation/AnnotationTransactionAttributeSource.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2015 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -150,10 +150,12 @@ public class AnnotationTransactionAttributeSource extends AbstractFallbackTransa
 	 * or {@code null} if none was found
 	 */
 	protected TransactionAttribute determineTransactionAttribute(AnnotatedElement ae) {
-		for (TransactionAnnotationParser annotationParser : this.annotationParsers) {
-			TransactionAttribute attr = annotationParser.parseTransactionAnnotation(ae);
-			if (attr != null) {
-				return attr;
+		if (ae.getAnnotations().length > 0) {
+			for (TransactionAnnotationParser annotationParser : this.annotationParsers) {
+				TransactionAttribute attr = annotationParser.parseTransactionAnnotation(ae);
+				if (attr != null) {
+					return attr;
+				}
 			}
 		}
 		return null;