DefaultAopProxyFactory falls back to JdkDynamicAopProxy when encountering JDK proxy as target

Issue: SPR-12870

spring-aop/src/main/java/org/springframework/aop/framework/AopProxyUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 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.
@@ -16,6 +16,7 @@
 
 package org.springframework.aop.framework;
 
+import java.lang.reflect.Proxy;
 import java.util.Arrays;
 
 import org.springframework.aop.SpringProxy;
@@ -83,8 +84,13 @@ public abstract class AopProxyUtils {
 		if (specifiedInterfaces.length == 0) {
 			// No user-specified interfaces: check whether target class is an interface.
 			Class<?> targetClass = advised.getTargetClass();
-			if (targetClass != null && targetClass.isInterface()) {
-				specifiedInterfaces = new Class<?>[] {targetClass};
+			if (targetClass != null) {
+				if (targetClass.isInterface()) {
+					specifiedInterfaces = new Class<?>[] {targetClass};
+				}
+				else if (Proxy.isProxyClass(targetClass)) {
+					specifiedInterfaces = targetClass.getInterfaces();
+				}
 			}
 		}
 		boolean addSpringProxy = !advised.isInterfaceProxied(SpringProxy.class);

spring-aop/src/main/java/org/springframework/aop/framework/DefaultAopProxyFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 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.
@@ -17,6 +17,7 @@
 package org.springframework.aop.framework;
 
 import java.io.Serializable;
+import java.lang.reflect.Proxy;
 
 import org.springframework.aop.SpringProxy;
 
@@ -53,7 +54,7 @@ public class DefaultAopProxyFactory implements AopProxyFactory, Serializable {
 				throw new AopConfigException("TargetSource cannot determine target class: " +
 						"Either an interface or a target is required for proxy creation.");
 			}
-			if (targetClass.isInterface()) {
+			if (targetClass.isInterface() || Proxy.isProxyClass(targetClass)) {
 				return new JdkDynamicAopProxy(config);
 			}
 			return new ObjenesisCglibAopProxy(config);
@@ -72,4 +73,5 @@ public class DefaultAopProxyFactory implements AopProxyFactory, Serializable {
 		Class<?>[] interfaces = config.getProxiedInterfaces();
 		return (interfaces.length == 0 || (interfaces.length == 1 && SpringProxy.class.equals(interfaces[0])));
 	}
+
 }

spring-context/src/test/java/org/springframework/aop/framework/autoproxy/AutoProxyCreatorTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 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.
@@ -17,6 +17,8 @@
 package org.springframework.aop.framework.autoproxy;
 
 import java.io.Serializable;
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.Method;
 import java.lang.reflect.Proxy;
 
 import org.aopalliance.intercept.MethodInterceptor;
@@ -42,6 +44,7 @@ import org.springframework.tests.sample.beans.ITestBean;
 import org.springframework.tests.sample.beans.IndexedTestBean;
 import org.springframework.tests.sample.beans.TestBean;
 import org.springframework.tests.sample.beans.factory.DummyFactory;
+import org.springframework.util.ReflectionUtils;
 
 import static org.junit.Assert.*;
 
@@ -207,6 +210,46 @@ public final class AutoProxyCreatorTests {
 		assertEquals(2, tapc.testInterceptor.nrOfInvocations);
 	}
 
+	@Test
+	public void testAutoProxyCreatorWithFallbackToDynamicProxy() {
+		StaticApplicationContext sac = new StaticApplicationContext();
+
+		MutablePropertyValues pvs = new MutablePropertyValues();
+		pvs.add("proxyFactoryBean", "false");
+		sac.registerSingleton("testAutoProxyCreator", TestAutoProxyCreator.class, pvs);
+
+		sac.registerSingleton("noInterfaces", NoInterfaces.class);
+		sac.registerSingleton("containerCallbackInterfacesOnly", ContainerCallbackInterfacesOnly.class);
+		sac.registerSingleton("singletonNoInterceptor", CustomProxyFactoryBean.class);
+		sac.registerSingleton("singletonToBeProxied", CustomProxyFactoryBean.class);
+		sac.registerPrototype("prototypeToBeProxied", CustomProxyFactoryBean.class);
+
+		sac.refresh();
+
+		MessageSource messageSource = (MessageSource) sac.getBean("messageSource");
+		NoInterfaces noInterfaces = (NoInterfaces) sac.getBean("noInterfaces");
+		ContainerCallbackInterfacesOnly containerCallbackInterfacesOnly =
+				(ContainerCallbackInterfacesOnly) sac.getBean("containerCallbackInterfacesOnly");
+		ITestBean singletonNoInterceptor = (ITestBean) sac.getBean("singletonNoInterceptor");
+		ITestBean singletonToBeProxied = (ITestBean) sac.getBean("singletonToBeProxied");
+		ITestBean prototypeToBeProxied = (ITestBean) sac.getBean("prototypeToBeProxied");
+		assertFalse(AopUtils.isCglibProxy(messageSource));
+		assertTrue(AopUtils.isCglibProxy(noInterfaces));
+		assertTrue(AopUtils.isCglibProxy(containerCallbackInterfacesOnly));
+		assertFalse(AopUtils.isCglibProxy(singletonNoInterceptor));
+		assertFalse(AopUtils.isCglibProxy(singletonToBeProxied));
+		assertFalse(AopUtils.isCglibProxy(prototypeToBeProxied));
+
+		TestAutoProxyCreator tapc = (TestAutoProxyCreator) sac.getBean("testAutoProxyCreator");
+		assertEquals(0, tapc.testInterceptor.nrOfInvocations);
+		singletonNoInterceptor.getName();
+		assertEquals(0, tapc.testInterceptor.nrOfInvocations);
+		singletonToBeProxied.getAge();
+		assertEquals(1, tapc.testInterceptor.nrOfInvocations);
+		prototypeToBeProxied.getSpouse();
+		assertEquals(2, tapc.testInterceptor.nrOfInvocations);
+	}
+
 	@Test
 	public void testAutoProxyCreatorWithFactoryBean() {
 		StaticApplicationContext sac = new StaticApplicationContext();
@@ -404,4 +447,30 @@ public final class AutoProxyCreatorTests {
 		}
 	}
 
+
+	public static class CustomProxyFactoryBean implements FactoryBean<ITestBean> {
+
+		private final TestBean tb = new TestBean();
+
+		@Override
+		public ITestBean getObject() {
+			return (ITestBean) Proxy.newProxyInstance(CustomProxyFactoryBean.class.getClassLoader(), new Class<?>[]{ITestBean.class}, new InvocationHandler() {
+				@Override
+				public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
+					return ReflectionUtils.invokeMethod(method, tb, args);
+				}
+			});
+		}
+
+		@Override
+		public Class<?> getObjectType() {
+			return ITestBean.class;
+		}
+
+		@Override
+		public boolean isSingleton() {
+			return false;
+		}
+	}
+
 }