java设计模式-代理模式

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();
}
}