Java设计模式之中介者模式详解

// 中介者接口
public interface Mediator {
    void notifyColleague(Colleague sender, String message);
}
// 具体中介者
public class ConcreteMediator implements Mediator {
    private Colleague colleague1;
    private Colleague colleague2;
    public void setColleague1(Colleague colleague1) {
        this.colleague1 = colleague1;
    }
    public void setColleague2(Colleague colleague2) {
        this.colleague2 = colleague2;
    }
    @Override
    public void notifyColleague(Colleague sender, String message) {
        if (sender == colleague1) {
            colleague2.receive(message);
        } else {
            colleague1.receive(message);
        }
    }
}
// 同事接口
public interface Colleague {
    void setMediator(Mediator mediator);
    void send(String message);
    void receive(String message);
}
// 具体同事
public class ConcreteColleague implements Colleague {
    private Mediator mediator;
    @Override
    public void setMediator(Mediator mediator) {
        this.mediator = mediator;
    }
    @Override
    public void send(String message) {
        mediator.notifyColleague(this, message);
    }
    @Override
    public void receive(String message) {
        System.out.println("Colleague received message: " + message);
    }
}

// 创建具体中介者对象
ConcreteMediator mediator = new ConcreteMediator();
// 创建具体同事对象
ConcreteColleague colleague1 = new ConcreteColleague();
ConcreteColleague colleague2 = new ConcreteColleague();
// 设置同事对象的中介者
colleague1.setMediator(mediator);
colleague2.setMediator(mediator);
// 设置中介者的同事对象
mediator.setColleague1(colleague1);
mediator.setColleague2(colleague2);
// 用户之间发送消息
colleague1.send("Hello, colleague2!");
colleague2.send("Hi, colleague1!");