代理模式

package test;//主题=代理主题(真实主题) interface Subject{     }class RealSubject implements Subject{ }class ProxySubject{    private Subject subject;    public ProxySubject(){}    public ProxySubject(Subject subject){        this.subject=subject;    }    public void start(){        System.out.println("启动");    }} public class Dailimoshi {    public static void main(String[] args) {        Subject realSubject=new RealSubject();        new ProxySubject(realSubject).start();    }}