代码是李刚老师书上的源码，有助于我们理解动态代理的原理。
Dog.java
package lee;/* * @author yeeku.H.lee kongyeeku@163.com * @version 1.0 * <br>Copyright (C), 2005-2008, yeeku.H.Lee * <br>This program is protected by copyright laws. * <br>Program Name: * <br>Date: */public interface Dog{ public void info(); public void run();}
DogImpl.java
package lee;/* * @author yeeku.H.lee kongyeeku@163.com * @version 1.0 * <br>Copyright (C), 2005-2008, yeeku.H.Lee * <br>This program is protected by copyright laws. * <br>Program Name: * <br>Date: */public class DogImpl implements Dog{ public void info() { System.out.println("我是一只猎狗"); } public void run() { System.out.println("我奔跑迅速"); }}
package lee;/** * @author yeeku.H.lee kongyeeku@163.com * @version 1.0 * <br>Copyright (C), 2005-2008, yeeku.H.Lee * <br>This program is protected by copyright laws. * <br>Program Name: * <br>Date: */public class DogIntercepter{ public void method1() { System.out.println("=====模拟通用方法一====="); } public void method2() { System.out.println("=====模拟通用方法二====="); }}
package lee;import java.lang.reflect.*;/* * @author yeeku.H.lee kongyeeku@163.com * @version 1.0 * <br>Copyright (C), 2005-2008, yeeku.H.Lee * <br>This program is protected by copyright laws. * <br>Program Name: * <br>Date: */public class MyProxyFactory{ /** * 实例Service对象。 * @param serviceName String * @return Object */ public static Object getProxy(Object object) { //Dog控制类 代理的操作类 ProxyHandler handler = new ProxyHandler(); //把该dog实例托付给代理操作 handler.setTarget(object); //第一个参数是用来创建 动态代理 的ClassLoader对象，只要该对象能访问Dog接口即可。 //也就只要DogImpl与Dog在同一 return Proxy.newProxyInstance(object.getClass().getClassLoader(),object.getClass().getInterfaces(),handler); }}
package lee;import java.lang.reflect.*;import java.util.*;/* * @author yeeku.H.lee kongyeeku@163.com * @version 1.0 * <br>Copyright (C), 2005-2008, yeeku.H.Lee * <br>This program is protected by copyright laws. * <br>Program Name: * <br>Date: */public class ProxyHandler implements InvocationHandler{ private Object target; DogIntercepter di = new DogIntercepter(); public Object invoke(Object proxy, Method method, Object[] args)throws Exception { Object result = null; if (method.getName().equals("info")) { di.method1(); result =method.invoke(target, args); di.method2(); } else { result =method.invoke(target, args); } return result; } public void setTarget(Object o) { this.target = o; }}
package lee;/* * @author yeeku.H.lee kongyeeku@163.com * @version 1.0 * <br>Copyright (C), 2005-2008, yeeku.H.Lee * <br>This program is protected by copyright laws. * <br>Program Name: * <br>Date: */public class TestDog{ public static void main(String[] args) { Dog targetObject = new DogImpl(); Dog dog = null; Object proxy = MyProxyFactory.getProxy(targetObject); if (proxy instanceof Dog) { dog = (Dog)proxy; } dog.info(); dog.run(); }}
