added "expose-proxy" attribute to aop namespace (enforcing AopContext proxy exposure with CGLIB; SPR-7261)

Author: jhoeller

org.springframework.aop/src/main/java/org/springframework/aop/config/AopConfigUtils.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.
@@ -97,6 +97,13 @@ public static void forceAutoProxyCreatorToUseClassProxying(BeanDefinitionRegistr
 		}
 	}
 
+	static void forceAutoProxyCreatorToExposeProxy(BeanDefinitionRegistry registry) {
+		if (registry.containsBeanDefinition(AUTO_PROXY_CREATOR_BEAN_NAME)) {
+			BeanDefinition definition = registry.getBeanDefinition(AUTO_PROXY_CREATOR_BEAN_NAME);
+			definition.getPropertyValues().add("exposeProxy", Boolean.TRUE);
+		}
+	}
+
 
 	private static BeanDefinition registerOrEscalateApcAsRequired(Class cls, BeanDefinitionRegistry registry, Object source) {
 		Assert.notNull(registry, "BeanDefinitionRegistry must not be null");

org.springframework.aop/src/main/java/org/springframework/aop/config/AopNamespaceUtils.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.
@@ -46,6 +46,11 @@ public abstract class AopNamespaceUtils {
 	 */
 	public static final String PROXY_TARGET_CLASS_ATTRIBUTE = "proxy-target-class";
 
+	/**
+	 * The <code>expose-proxy</code> attribute as found on AOP-related XML tags.
+	 */
+	private static final String EXPOSE_PROXY_ATTRIBUTE = "expose-proxy";
+
 
 	public static void registerAutoProxyCreatorIfNecessary(
 			ParserContext parserContext, Element sourceElement) {
@@ -102,6 +107,10 @@ private static void useClassProxyingIfNecessary(BeanDefinitionRegistry registry,
 			if (proxyTargetClass) {
 				AopConfigUtils.forceAutoProxyCreatorToUseClassProxying(registry);
 			}
+			boolean exposeProxy = Boolean.valueOf(sourceElement.getAttribute(EXPOSE_PROXY_ATTRIBUTE));
+			if (exposeProxy) {
+				AopConfigUtils.forceAutoProxyCreatorToExposeProxy(registry);
+			}
 		}
 	}
 

org.springframework.aop/src/main/java/org/springframework/aop/framework/Cglib2AopProxy.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.
@@ -268,7 +268,7 @@ private Callback[] getCallbacks(Class rootClass) throws Exception {
 
 		// Choose a "straight to target" interceptor. (used for calls that are
 		// unadvised but can return this). May be required to expose the proxy.
-		Callback targetInterceptor = null;
+		Callback targetInterceptor;
 		if (exposeProxy) {
 			targetInterceptor = isStatic ?
 					new StaticUnadvisedExposedInterceptor(this.advised.getTargetSource().getTarget()) :
@@ -316,12 +316,8 @@ private Callback[] getCallbacks(Class rootClass) throws Exception {
 			// Now copy both the callbacks from mainCallbacks
 			// and fixedCallbacks into the callbacks array.
 			callbacks = new Callback[mainCallbacks.length + fixedCallbacks.length];
-			for (int x = 0; x < mainCallbacks.length; x++) {
-				callbacks[x] = mainCallbacks[x];
-			}
-			for (int x = 0; x < fixedCallbacks.length; x++) {
-				callbacks[x + mainCallbacks.length] = fixedCallbacks[x];
-			}
+			System.arraycopy(mainCallbacks, 0, callbacks, 0, mainCallbacks.length);
+			System.arraycopy(fixedCallbacks, 0, callbacks, mainCallbacks.length, fixedCallbacks.length);
 			this.fixedInterceptorOffset = mainCallbacks.length;
 		}
 		else {
@@ -610,7 +606,7 @@ public Object intercept(Object proxy, Method method, Object[] args, MethodProxy
 					targetClass = target.getClass();
 				}
 				List<Object> chain = this.advised.getInterceptorsAndDynamicInterceptionAdvice(method, targetClass);
-				Object retVal = null;
+				Object retVal;
 				// Check whether we only have one InvokerInterceptor: that is,
 				// no real advice, but just reflective invocation of the target.
 				if (chain.isEmpty() && Modifier.isPublic(method.getModifiers())) {

org.springframework.aop/src/main/java/org/springframework/aop/framework/ProxyConfig.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2007 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.
@@ -113,12 +113,14 @@ public boolean isOpaque() {
 	 * ThreadLocal for retrieval via the AopContext class. This is useful
 	 * if an advised object needs to call another advised method on itself.
 	 * (If it uses <code>this</code>, the invocation will not be advised).
-	 * <p>Default is "false", for optimal performance.
+	 * <p>Default is "false", in order to avoid unnecessary extra interception.
+	 * This means that no guarantees are provided that AopContext access will
+	 * work consistently within any method of the advised object.
 	 */
 	public void setExposeProxy(boolean exposeProxy) {
 		this.exposeProxy = exposeProxy;
 	}
-	
+
 	/**
 	 * Return whether the AOP proxy will expose the AOP proxy for
 	 * each invocation.

org.springframework.aop/src/main/resources/org/springframework/aop/config/spring-aop-3.0.xsd

@@ -56,6 +56,15 @@
 					]]></xsd:documentation>
 				</xsd:annotation>
 			</xsd:attribute>
+			<xsd:attribute name="expose-proxy" type="xsd:boolean" default="false">
+				<xsd:annotation>
+					<xsd:documentation><![CDATA[
+	Indicate that the proxy should be exposed by the AOP framework as a
+	ThreadLocal for retrieval via the AopContext class. Off by default,
+	i.e. no guarantees that AopContext access will work.
+					]]></xsd:documentation>
+				</xsd:annotation>
+			</xsd:attribute>
 		</xsd:complexType>
 	</xsd:element>
 
@@ -84,6 +93,15 @@
 					]]></xsd:documentation>
 				</xsd:annotation>
 			</xsd:attribute>
+			<xsd:attribute name="expose-proxy" type="xsd:boolean" default="false">
+				<xsd:annotation>
+					<xsd:documentation><![CDATA[
+	Indicate that the proxy should be exposed by the AOP framework as a
+	ThreadLocal for retrieval via the AopContext class. Off by default,
+	i.e. no guarantees that AopContext access will work.
+					]]></xsd:documentation>
+				</xsd:annotation>
+			</xsd:attribute>
 		</xsd:complexType>
 	</xsd:element>