代理模式

以追女孩为例，需要人帮忙送礼物

实现

女孩

public class Girl {

    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Girl(String name){
        this.name = name;
    }

}

接口

public interface IGiveGift {

    void sendFlower();
    void sendSnack();
    void sendChocolate();

}

男孩

public class Boy implements IGiveGift {

    private Girl girl;

    public Boy(Girl girl){
        this.girl = girl;
    }

    @Override
    public void sendFlower(){
        System.out.println("给 "+this.girl.getName()+" 送花");
    }

    @Override
    public void sendSnack(){
        System.out.println("给 "+this.girl.getName()+" 送零食");
    }

    @Override
    public void sendChocolate(){
        System.out.println("给 "+this.girl.getName()+" 送巧克力");
    }
}

代理同学

public class Proxy implements IGiveGift {

    private Boy boy;

    public Proxy(Girl girl){
        this.boy = new Boy(girl);
    }
    
    @Override
    public void sendFlower() {
        System.out.println("代理同学，帮忙送花");
        this.boy.sendFlower();
        System.out.println("花送完了");
    }

    @Override
    public void sendSnack() {
        System.out.println("代理同学，帮忙送零食");
        this.boy.sendSnack();
        System.out.println("送完零食");
    }

    @Override
    public void sendChocolate() {
        System.out.println("代理同学，帮忙送巧克力");
        this.boy.sendChocolate();
        System.out.println("送完巧克力");
    }
}

使用

public static void main(String[] args) {
        Girl girl = new Girl("小丽");
        Proxy proxy = new Proxy(girl);
        proxy.sendChocolate();
    }

打印

代理同学，帮忙送巧克力
给 小丽 送巧克力
送完巧克力