设计模式——中介者模式

很常用的一种设计模式，比如所谓的MVP架构就是典型的中介者模式

MVC 框架时代， M V C 三者之间皆可以相互操作，导致后期维护的难度升高，之后就引入了MVP架构来进行解耦，本质就是使用中介者模式的思想。

这里就不多做解释了，大家应该都用过MVP吧

还是举个例子：

现在有n个买家和n个卖家；他们如果相互交流就会比较麻烦，比较乱，我们引入一个中介（对，就像现实的中间商）来对接两头就ok了。

定义买方中介接口

public interface SolderMediary {
  
    void sendMessageToBuyer(String msg);
}

定义卖方中介接口

public interface BuyerMediary {
  
    void sendMessageToSolder(String msg);
}

定义中介者

public class Market implements SolderMediary, BuyerMediary {
    private Buyer buyer;
    private Solder solder;

    public void setBuyer(Buyer buyer) {
        this.buyer = buyer;
    }

    public void setSolder(Solder solder) {
        this.solder = solder;
    }

    @Override
    public void sendMessageToSolder(String msg) {
        super.sendMessage(msg);
        solder.handleMsg(msg);
    }
  
    @Override
    public void sendMessageToBuyer(String msg) {
        super.sendMessage(msg);
        buyer.handleMsg(msg)
    }
}

定义卖方类

public class Solder {
  
    BuyerMediary mediary;
  
    public Solder(BuyerMediary mediary) {
        this.mediary = mediary;
    }

    void sendMessage(String message) {
        this.mediary.sendMessageToBuyer(message);
    }
}

定义买方类

public class Buyer {
  
    SolderMediary mediary;
  
    public Buyer(SolderMediary mediary) {
        this.mediary = mediary;
    }

    @Override
    void sendMessage(String message) {
        super.sendMessage(message);
        this.mediary.sendMessageToSolder(message);
    }
}