package proxy;/** * 抽象主题，定义主要功能 */public interface Subject {     public void operate();}

package proxy;public class Proxy implements Subject{    private Subject subject;        public Proxy(Subject subject) {        this.subject = subject;    }        public void operate() {        System.out.println("before operate......");        subject.operate();        System.out.println("after operate......");    }}

package proxy;public class RealSubject implements Subject{    public void operate() {        System.out.println("realsubject operatestarted......");    }}

package proxy;public class Client {    public static void main(String[] args) {         Subject subject = new RealSubject();            Proxy proxy = new Proxy(subject);            proxy.operate();    }}