java--代理设计模式

public class Main {    public static void main(String[] args) {        Subject subject = new RealSubject();        ProxySubject proxy = new ProxySubject(subject);        proxy.operate();    }}//抽象主题,定义主要功能interface Subject{    public abstract void operate();}//真实主题class  RealSubject implements Subject{    public void operate(){        System.out.println("realsubject 操作");    }}//代理主题class ProxySubject implements Subject{    private Subject subject;    public ProxySubject(Subject subject){        this.subject = subject;    }    public void operate(){        System.out.println("操作前");        subject.operate();        System.out.println("操作后");    }}