Distinguish between different bridge method types

Add BridgeMethodResolver#isJava6VisibilityBridgeMethodPair to
distinguish between (a) bridge methods introduced in Java 6 to
compensate for inheriting public methods from non-public superclasses
and (b) bridge methods that have existed since Java 5 to accommodate
return type covariance and generic parameters.

In the former case, annotations should be looked up from the original
bridged method (SPR-7900).  In the latter, the annotation should be
looked up against the bridge method itself (SPR-8660).

As noted in the Javadoc for the new method, see
http://stas-blogspot.blogspot.com/2010/03/java-bridge-methods-explained.html
for a useful description of the various types of bridge methods, as
well as http://bugs.sun.com/view_bug.do?bug_id=6342411, the bug fixed in
Java 6 resulting in the introduction of 'visibility bridge methods'.

Issue: SPR-8660, SPR-7900

Author: cbeams

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

@@ -16,6 +16,9 @@
 
 package org.springframework.beans.factory.annotation;
 
+import static org.springframework.core.BridgeMethodResolver.findBridgedMethod;
+import static org.springframework.core.BridgeMethodResolver.isJava6VisibilityBridgeMethodPair;
+
 import java.beans.PropertyDescriptor;
 import java.lang.annotation.Annotation;
 import java.lang.reflect.AccessibleObject;
@@ -35,7 +38,6 @@
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-
 import org.springframework.beans.BeanUtils;
 import org.springframework.beans.BeansException;
 import org.springframework.beans.PropertyValues;
@@ -50,7 +52,6 @@
 import org.springframework.beans.factory.config.RuntimeBeanReference;
 import org.springframework.beans.factory.support.MergedBeanDefinitionPostProcessor;
 import org.springframework.beans.factory.support.RootBeanDefinition;
-import org.springframework.core.BridgeMethodResolver;
 import org.springframework.core.GenericTypeResolver;
 import org.springframework.core.MethodParameter;
 import org.springframework.core.Ordered;
@@ -342,7 +343,10 @@ private InjectionMetadata buildAutowiringMetadata(Class<?> clazz) {
 				}
 			}
 			for (Method method : targetClass.getDeclaredMethods()) {
-				Annotation annotation = findAutowiredAnnotation(method);
+				Method bridgedMethod = findBridgedMethod(method);
+				Annotation annotation = isJava6VisibilityBridgeMethodPair(method, bridgedMethod) ?
+						findAutowiredAnnotation(bridgedMethod) :
+						findAutowiredAnnotation(method);
 				if (annotation != null && method.equals(ClassUtils.getMostSpecificMethod(method, clazz))) {
 					if (Modifier.isStatic(method.getModifiers())) {
 						if (logger.isWarnEnabled()) {
@@ -370,9 +374,6 @@ private InjectionMetadata buildAutowiringMetadata(Class<?> clazz) {
 
 	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.context/src/test/java/org/springframework/beans/factory/annotation/BridgeMethodAutowiringTests.java

@@ -0,0 +1,61 @@
+/*
+ * 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.beans.factory.annotation;
+
+import static org.junit.Assert.assertNotNull;
+
+import javax.inject.Inject;
+import javax.inject.Named;
+
+import org.junit.Test;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.stereotype.Component;
+
+public class BridgeMethodAutowiringTests {
+
+	@Test
+	public void SPR_8434() {
+		AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext();
+		ctx.register(UserServiceImpl.class, Foo.class);
+		ctx.refresh();
+		assertNotNull(ctx.getBean(UserServiceImpl.class).object);
+	}
+
+}
+
+
+abstract class GenericServiceImpl<D extends Object> {
+
+	public abstract void setObject(D object);
+
+}
+
+
+class UserServiceImpl extends GenericServiceImpl<Foo> {
+
+	protected Foo object;
+
+	@Inject
+	@Named("userObject")
+	public void setObject(Foo object) {
+		this.object = object;
+	}
+}
+
+@Component("userObject")
+class Foo { }
+

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

@@ -25,6 +25,7 @@
 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 @@ private static Method searchForMatch(Class type, Method bridgeMethod) {
 		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 isJava6VisibilityBridgeMethodPair(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());
+	}
+
+
 }