advisedsupport.java

一个关于Spring框架的示例应用程序,简单使用,可以参考.

/*
 * Copyright 2002-2004 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.aop.framework;

import java.io.ObjectStreamException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;

import org.aopalliance.aop.Advice;
import org.aopalliance.intercept.Interceptor;
import org.aopalliance.intercept.MethodInterceptor;
import org.apache.commons.logging.LogFactory;

import org.springframework.aop.Advisor;
import org.springframework.aop.AfterReturningAdvice;
import org.springframework.aop.DynamicIntroductionAdvice;
import org.springframework.aop.IntroductionAdvisor;
import org.springframework.aop.IntroductionInfo;
import org.springframework.aop.MethodBeforeAdvice;
import org.springframework.aop.Pointcut;
import org.springframework.aop.TargetSource;
import org.springframework.aop.ThrowsAdvice;
import org.springframework.aop.support.AopUtils;
import org.springframework.aop.support.DefaultIntroductionAdvisor;
import org.springframework.aop.support.DefaultPointcutAdvisor;
import org.springframework.aop.target.EmptyTargetSource;
import org.springframework.aop.target.SingletonTargetSource;
import org.springframework.util.StringUtils;

/**
 * Superclass for AOP proxy configuration managers.
 * These are not themselves AOP proxies, but subclasses of this class are
 * normally factories from which AOP proxy instances are obtained directly.
 *
 * <p>This class frees subclasses of the housekeeping of Advices
 * and Advisors, but doesn't actually implement proxy creation
 * methods, which are provided by subclasses.
 *
 * <p>This class is serializable; subclasses need not be.
 * This class is used to hold snapshots of proxies.
 *
 * @author Rod Johnson
 * @see org.springframework.aop.framework.AopProxy
 */
public class AdvisedSupport extends ProxyConfig implements Advised {
	
	/**
	 * Canonical TargetSource when there's no target, and behavior is
	 * supplied by the advisors.
	 */
	public static final TargetSource EMPTY_TARGET_SOURCE = EmptyTargetSource.INSTANCE;


	/** List of AdvisedSupportListener */
	private transient List listeners = new LinkedList();

	/**
	 * Package-protected to allow direct access for efficiency
	 */
	TargetSource targetSource = EMPTY_TARGET_SOURCE;

	transient AdvisorChainFactory advisorChainFactory;

	/**
	 * List of Advice. If an Interceptor is added, it will be wrapped
	 * in an Advice before being added to this List. 
	 */
	private List advisors = new LinkedList();
	
	/**
	 * Array updated on changes to the advisors list, which is easier
	 * to manipulate internally.
	 */
	private Advisor[] advisorArray = new Advisor[0];

	/**
	 * Interfaces to be implemented by the proxy. Held in List to keep the order
	 * of registration, to create JDK proxy with specified order of interfaces.
	 */
	private List interfaces = new ArrayList();

	/**
	 * Set to true when the first AOP proxy has been created, meaning that we
	 * must track advice changes via onAdviceChange callback.
	 */
	private transient boolean isActive;


	/**
	 * No arg constructor to allow use as a JavaBean.
	 */
	public AdvisedSupport() {
		initDefaultAdvisorChainFactory();
	}
	
	/**
	 * Create a DefaultProxyConfig with the given parameters.
	 * @param interfaces the proxied interfaces
	 */
	public AdvisedSupport(Class[] interfaces) {
		this();
		setInterfaces(interfaces);
	}

	/**
	 * Initialize the default AdvisorChainFactory.
	 */
	private void initDefaultAdvisorChainFactory() {
		setAdvisorChainFactory(new HashMapCachingAdvisorChainFactory());
	}


	public void addListener(AdvisedSupportListener listener) {
		this.listeners.add(listener);
	}

	public void removeListener(AdvisedSupportListener listener) {
		this.listeners.remove(listener);
	}

	/**
	 * Set the given object as target.
	 * Will create a SingletonTargetSource for the object.
	 * @see #setTargetSource
	 * @see org.springframework.aop.target.SingletonTargetSource
	 */
	public void setTarget(Object target) {
		setTargetSource(new SingletonTargetSource(target));
	}

	public void setTargetSource(TargetSource targetSource) {
		if (isActive() && isOptimize()) {
			throw new AopConfigException("Can't change target with an optimized CGLIB proxy: it has its own target");
		}
		this.targetSource = (targetSource != null ? targetSource : EMPTY_TARGET_SOURCE);
	}
	
	public TargetSource getTargetSource() {
		return this.targetSource;
	}
	
	public void setAdvisorChainFactory(AdvisorChainFactory advisorChainFactory) {
		this.advisorChainFactory = advisorChainFactory;
		addListener(advisorChainFactory);
	}
	
	public AdvisorChainFactory getAdvisorChainFactory() {
		return this.advisorChainFactory;
	}


	/**
	 * Call this method on a new instance created by the no-arg constructor
	 * to create an independent copy of the configuration from the other.
	 * @param other AdvisedSupport to copy configuration from
	 */
	protected void copyConfigurationFrom(AdvisedSupport other) {
		copyConfigurationFrom(other, other.targetSource, other.advisors);
	}

	/**
	 * Take interfaces and ProxyConfig configuration from the
	 * other AdvisedSupport, but allow substitution of a fresh
	 * TargetSource and interceptor chain
	 * @param other other AdvisedSupport object to take
	 * interfaces and ProxyConfig superclass configuration from
	 * @param ts new TargetSource
	 * @param pAdvisors new Advisor chain
	 */
	protected void copyConfigurationFrom(AdvisedSupport other, TargetSource ts, List pAdvisors) {
		copyFrom(other);
		this.targetSource = ts;
		setInterfaces((Class[]) other.interfaces.toArray(new Class[other.interfaces.size()]));
		this.advisors = new LinkedList();
		for (int i = 0; i < pAdvisors.size(); i++) {
			Advisor advice = (Advisor) pAdvisors.get(i);
			addAdvisor(advice);
		}
	}

	/**
	 * Set the interfaces to be proxied.
	 */
	public void setInterfaces(Class[] interfaces) {
		this.interfaces.clear();
		for (int i = 0; i < interfaces.length; i++) {
			addInterface(interfaces[i]);
		}
	}

	/**
	 * Add a new proxied interface.
	 * @param newInterface additional interface to proxy
	 */
	public void addInterface(Class newInterface) {
		if (!newInterface.isInterface()) {
			throw new IllegalArgumentException("[" + newInterface.getName() + "] is not an interface");
		}
		if (!this.interfaces.contains(newInterface)) {
			this.interfaces.add(newInterface);
			adviceChanged();
			if (logger.isDebugEnabled()) {
				logger.debug("Added new aspect interface: " + newInterface.getName());
			}
		}
	}

	public Class[] getProxiedInterfaces() {
		return (Class[]) this.interfaces.toArray(new Class[this.interfaces.size()]);
	}

	/**
	 * Remove a proxied interface.
	 * Does nothing if it isn't proxied.
	 */
	public boolean removeInterface(Class intf) {
		return this.interfaces.remove(intf);
	}
	
	/**
	 * @deprecated in favor of addAdvice
	 * @see #addAdvice(org.aopalliance.aop.Advice)
	 * @see Advised#addInterceptor(org.aopalliance.intercept.Interceptor)
	 */
	public void addInterceptor(Interceptor interceptor) throws AopConfigException {
		addAdvice(interceptor);
	}

	public void addAdvice(Advice advice) throws AopConfigException {
		int pos = (this.advisors != null) ? this.advisors.size() : 0;
		addAdvice(pos, advice);
	}
	
	public boolean isInterfaceProxied(Class intf) {
		for (Iterator it = this.interfaces.iterator(); it.hasNext();) {
			Class proxyIntf = (Class) it.next();
			if (intf.isAssignableFrom(proxyIntf)) {
				return true;
			}
		}
		return false;
	}

	/**
	 * @deprecated in favor of addAdvice
	 * @see #addAdvice(int, org.aopalliance.aop.Advice)
	 * @see Advised#addInterceptor(int, org.aopalliance.intercept.Interceptor)
	 */
	public void addInterceptor(int pos, Interceptor interceptor) throws AopConfigException {
		addAdvice(pos, interceptor);
	}
	
	/**
	 * Cannot add introductions this way unless the advice implements IntroductionInfo.
	 */
	public void addAdvice(int pos, Advice advice) throws AopConfigException {
		if (advice instanceof Interceptor && !(advice instanceof MethodInterceptor)) {
			throw new AopConfigException(getClass().getName() + " only handles AOP Alliance MethodInterceptors");
		}
		
		if (advice instanceof IntroductionInfo) {
			// We don't need an IntroductionAdvisor for this kind of introduction:
			// it's fully self-describing
			addAdvisor(pos, new DefaultIntroductionAdvisor(advice, (IntroductionInfo) advice));
		}
		else if (advice instanceof DynamicIntroductionAdvice) {
			// We need an IntroductionAdvisor for this kind of introduction
			throw new AopConfigException("DynamicIntroductionAdvice may only be added as part of IntroductionAdvisor");
		}
		else {
			addAdvisor(pos, new DefaultPointcutAdvisor(advice));
		}
	}
	
	
	/**
	 * Convenience method to remove an interceptor.
	 * @deprecated in favor or removeAdvice
	 * @see #removeAdvice
	 */
	public final boolean removeInterceptor(Interceptor interceptor) throws AopConfigException {
		return removeAdvice(interceptor);
	}
	
	/**
	 * Remove the Advisor containing the given advice
	 * @param advice advice to remove
	 * @return whether the Advice was found and removed (false if
	 * there was no such advice)
	 */
	public final boolean removeAdvice(Advice advice) throws AopConfigException {
		int index = indexOf(advice);
		if (index == -1) {
			return false;
		}
		else {
			removeAdvisor(index);
			return true;
		}
	}

	/**
	 * @deprecated in favor of addAdvice
	 * @see #addAdvice(org.aopalliance.aop.Advice)
	 * @see Advised#addAfterReturningAdvice
	 */
	public void addAfterReturningAdvice(AfterReturningAdvice ara) throws AopConfigException {
		addAdvisor(new DefaultPointcutAdvisor(Pointcut.TRUE, ara));
	}
	
	/**
	 * @deprecated in favor of addAdvice