动态代理（Dynamic Proxy）

1. 接口

package dynamic.proxy;public interface ISubject { public void request();} 

2. 业务类（要被代理的类）

package dynamic.proxy;public class RealSubject implements ISubject { @Override public void request() { System.out.println("RealSubject request() ...."); }} 

3. 代理类

package dynamic.proxy;import java.lang.reflect.InvocationHandler;import java.lang.reflect.Method;public class DynamicProxy implements InvocationHandler { // 被代理类的实例 Object obj = null; public DynamicProxy(Object obj){ this.obj = obj; } @Override public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { // 真正服务执行前，可动态添加的行为 Object result = method.invoke(this.obj, args); // 真正服务之星后，可动态添加的行为 return result; }} 

4. 测试类

package dynamic.proxy;import java.lang.reflect.InvocationHandler;import java.lang.reflect.Proxy;public class Client { public static void main(String[] args){ ISubject realSubject = new RealSubject(); ClassLoader loader = realSubject.getClass().getClassLoader(); Class<?>[] interfaces = realSubject.getClass().getInterfaces(); InvocationHandler handler = new DynamicProxy(realSubject); ISubject proxy = (ISubject) Proxy.newProxyInstance(loader, interfaces, handler); proxy.request(); System.out.println(proxy.getClass().getName()); }}