introduced AopProxyUtils.ultimateTargetClass (SPR-7074)

jhoeller · jhoeller · commit 87e327773ee7 · 2010-04-22T21:36:53.000Z
diff --git a/org.springframework.aop/src/main/java/org/springframework/aop/framework/AopProxyUtils.java b/org.springframework.aop/src/main/java/org/springframework/aop/framework/AopProxyUtils.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2008 the original author or authors.
+ * Copyright 2002-2010 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.
@@ -19,6 +19,9 @@
 import java.util.Arrays;
 
 import org.springframework.aop.SpringProxy;
+import org.springframework.aop.TargetClassAware;
+import org.springframework.aop.TargetSource;
+import org.springframework.aop.target.SingletonTargetSource;
 import org.springframework.util.Assert;
 
 /**
@@ -34,6 +37,34 @@
  */
 public abstract class AopProxyUtils {
 
+	/**
+	 * Determine the ultimate target class of the given bean instance, traversing
+	 * not only a top-level proxy but any number of nested proxies as well -
+	 * as long as possible without side effects, that is, just for singleton targets.
+	 * @param candidate the instance to check (might be an AOP proxy)
+	 * @return the target class (or the plain class of the given object as fallback;
+	 * never <code>null</code>)
+	 * @see org.springframework.aop.TargetClassAware#getTargetClass()
+	 * @see org.springframework.aop.framework.Advised#getTargetSource()
+	 */
+	public static Class<?> ultimateTargetClass(Object candidate) {
+		Assert.notNull(candidate, "Candidate object must not be null");
+		Object current = candidate;
+		Class<?> result = null;
+		while (current instanceof TargetClassAware) {
+			result = ((TargetClassAware) current).getTargetClass();
+			Object nested = null;
+			if (current instanceof Advised) {
+				TargetSource targetSource = ((Advised) current).getTargetSource();
+				if (targetSource instanceof SingletonTargetSource) {
+					nested = ((SingletonTargetSource) targetSource).getTarget();
+				}
+			}
+			current = nested;
+		}
+		return result;
+	}
+
 	/**
 	 * Determine the complete set of interfaces to proxy for the given AOP configuration.
 	 * <p>This will always add the {@link Advised} interface unless the AdvisedSupport's
diff --git a/org.springframework.aop/src/main/java/org/springframework/aop/support/AopUtils.java b/org.springframework.aop/src/main/java/org/springframework/aop/support/AopUtils.java
@@ -98,13 +98,13 @@ public static boolean isCglibProxyClassName(String className) {
 	}
 
 	/**
-	 * Determine the target class of the given bean instance,
-	 * which might be an AOP proxy.
+	 * Determine the target class of the given bean instance which might be an AOP proxy.
 	 * <p>Returns the target class for an AOP proxy and the plain class else.
 	 * @param candidate the instance to check (might be an AOP proxy)
 	 * @return the target class (or the plain class of the given object as fallback;
 	 * never <code>null</code>)
 	 * @see org.springframework.aop.TargetClassAware#getTargetClass()
+	 * @see org.springframework.aop.framework.AopProxyUtils#ultimateTargetClass(Object)
 	 */
 	public static Class<?> getTargetClass(Object candidate) {
 		Assert.notNull(candidate, "Candidate object must not be null");
diff --git a/org.springframework.aop/src/test/java/org/springframework/aop/framework/ProxyFactoryTests.java b/org.springframework.aop/src/test/java/org/springframework/aop/framework/ProxyFactoryTests.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2009 the original author or authors.
+ * Copyright 2002-2010 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.
@@ -293,20 +293,33 @@ public void testCanAddAndRemoveAspectInterfacesOnSingleton() {
 	public void testProxyTargetClassWithInterfaceAsTarget() {
 		ProxyFactory pf = new ProxyFactory();
 		pf.setTargetClass(ITestBean.class);
-
 		Object proxy = pf.getProxy();
 		assertTrue("Proxy is a JDK proxy", AopUtils.isJdkDynamicProxy(proxy));
 		assertTrue(proxy instanceof ITestBean);
+		assertEquals(ITestBean.class, AopProxyUtils.ultimateTargetClass(proxy));
+
+		ProxyFactory pf2 = new ProxyFactory(proxy);
+		Object proxy2 = pf2.getProxy();
+		assertTrue("Proxy is a JDK proxy", AopUtils.isJdkDynamicProxy(proxy2));
+		assertTrue(proxy2 instanceof ITestBean);
+		assertEquals(ITestBean.class, AopProxyUtils.ultimateTargetClass(proxy2));
 	}
 
 	@Test
 	public void testProxyTargetClassWithConcreteClassAsTarget() {
 		ProxyFactory pf = new ProxyFactory();
 		pf.setTargetClass(TestBean.class);
-
 		Object proxy = pf.getProxy();
 		assertTrue("Proxy is a CGLIB proxy", AopUtils.isCglibProxy(proxy));
 		assertTrue(proxy instanceof TestBean);
+		assertEquals(TestBean.class, AopProxyUtils.ultimateTargetClass(proxy));
+
+		ProxyFactory pf2 = new ProxyFactory(proxy);
+		pf2.setProxyTargetClass(true);
+		Object proxy2 = pf2.getProxy();
+		assertTrue("Proxy is a CGLIB proxy", AopUtils.isCglibProxy(proxy2));
+		assertTrue(proxy2 instanceof TestBean);
+		assertEquals(TestBean.class, AopProxyUtils.ultimateTargetClass(proxy2));
 	}
 
 	@Test
