backported Java 6 visibility bridge method pair (SPR-8660)

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

@@ -62,8 +62,11 @@ import org.springframework.util.ReflectionUtils;
 /**
  * {@link org.springframework.beans.factory.config.BeanPostProcessor} implementation
  * that autowires annotated fields, setter methods and arbitrary config methods.
- * Such members to be injected are detected through a Java 5 annotation:
+ * Such members to be injected are detected through a Java 5 annotation: by default,
- * by default, Spring's @{@link Autowired} and @{@link Value} annotations.
+ * Spring's {@link Autowired @Autowired} and {@link Value @Value} annotations.
+ *
+ * <p>Also supports JSR-330's {@link javax.inject.Inject @Inject} annotation,
+ * if available, as a direct alternative to Spring's own <code>@Autowired</code>.
  *
  * <p>Only one constructor (at max) of any given bean class may carry this
  * annotation with the 'required' parameter set to <code>true</code>, 
@@ -78,14 +81,10 @@ import org.springframework.util.ReflectionUtils;
  * <p>Fields are injected right after construction of a bean, before any
  * config methods are invoked. Such a config field does not have to be public.
  *
- * <p>Config methods may have an arbitrary name and any number of arguments;
+ * <p>Config methods may have an arbitrary name and any number of arguments; each of
- * each of those arguments will be autowired with a matching bean in the
+ * those arguments will be autowired with a matching bean in the Spring container.
- * Spring container. Bean property setter methods are effectively just
+ * Bean property setter methods are effectively just a special case of such a
- * a special case of such a general config method. Such config methods
+ * general config method. Config methods do not have to be public.
- * do not have to be public.
- *
- * <p>Also supports JSR-330's {@link javax.inject.Inject @Inject} annotation, if
- * available.
  *
  * <p>Note: A default AutowiredAnnotationBeanPostProcessor will be registered
  * by the "context:annotation-config" and "context:component-scan" XML tags.
@@ -343,7 +342,9 @@ public class AutowiredAnnotationBeanPostProcessor extends InstantiationAwareBean
 				}
 			}
 			for (Method method : targetClass.getDeclaredMethods()) {
-				Annotation annotation = findAutowiredAnnotation(method);
+				Method bridgedMethod = BridgeMethodResolver.findBridgedMethod(method);
+				Annotation annotation = BridgeMethodResolver.isVisibilityBridgeMethodPair(method, bridgedMethod) ?
+						findAutowiredAnnotation(bridgedMethod) : findAutowiredAnnotation(method);
 				if (annotation != null && method.equals(ClassUtils.getMostSpecificMethod(method, clazz))) {
 					if (Modifier.isStatic(method.getModifiers())) {
 						if (logger.isWarnEnabled()) {
@@ -371,9 +372,6 @@ public class AutowiredAnnotationBeanPostProcessor extends InstantiationAwareBean
 
 	private Annotation findAutowiredAnnotation(AccessibleObject ao) {
 		for (Class<? extends Annotation> type : this.autowiredAnnotationTypes) {
-			if (ao instanceof Method) {
-				ao = BridgeMethodResolver.findBridgedMethod((Method) ao);
-			}
 			Annotation annotation = ao.getAnnotation(type);
 			if (annotation != null) {
 				return annotation;

org.springframework.core/src/main/java/org/springframework/core/BridgeMethodResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2009 the original author or authors.
+ * Copyright 2002-2011 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.
@@ -25,6 +25,7 @@ import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 
+import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.ReflectionUtils;
 
@@ -210,4 +211,22 @@ public abstract class BridgeMethodResolver {
 		return ReflectionUtils.findMethod(type, bridgeMethod.getName(), bridgeMethod.getParameterTypes());
 	}
 
+	/**
+	 * Compare the signatures of the bridge method and the method which it bridges. If
+	 * the parameter and return types are the same, it is a 'visibility' bridge method
+	 * introduced in Java 6 to fix http://bugs.sun.com/view_bug.do?bug_id=6342411.
+	 * See also http://stas-blogspot.blogspot.com/2010/03/java-bridge-methods-explained.html
+	 * @return whether signatures match as described
+	 */
+	public static boolean isVisibilityBridgeMethodPair(Method bridgeMethod, Method bridgedMethod) {
+		Assert.isTrue(bridgeMethod != null);
+		Assert.isTrue(bridgedMethod != null);
+		if (bridgeMethod == bridgedMethod) {
+			return true;
+		}
+		return Arrays.equals(bridgeMethod.getParameterTypes(), bridgedMethod.getParameterTypes()) &&
+				bridgeMethod.getReturnType().equals(bridgedMethod.getReturnType());
+	}
+
+
 }