设计模式-中介者模式

// Mediator接口定义了send()方法，用于处理对象之间的交互。
interface Mediator {
    void send(String message, Colleague colleague);
}
 // Colleague抽象类表示对象，它包含一个Mediator对象，用于处理对象之间的通信。
abstract class Colleague {
    protected Mediator mediator;
     public Colleague(Mediator mediator) {
        this.mediator = mediator;
    }
     public abstract void receive(String message);
     public abstract void send(String message);
}
 // ConcreteColleague1和ConcreteColleague2是具体的对象实现类，它们实现了Colleague抽象类中的方法。
class ConcreteColleague1 extends Colleague {
    public ConcreteColleague1(Mediator mediator) {
        super(mediator);
    }
     @Override
    public void receive(String message) {
        System.out.println("Colleague1 received message: " + message);
    }
     @Override
    public void send(String message) {
        System.out.println("Colleague1 sends message: " + message);
        mediator.send(message, this);
    }
}
 class ConcreteColleague2 extends Colleague {
    public ConcreteColleague2(Mediator mediator) {
        super(mediator);
    }
     @Override
    public void receive(String message) {
        System.out.println("Colleague2 received message: " + message);
    }
     @Override
    public void send(String message) {
        System.out.println("Colleague2 sends message: " + message);
        mediator.send(message, this);
    }
}
 // ConcreteMediator是具体的中介者实现类，它负责协调对象之间的通信。
class ConcreteMediator implements Mediator {
    private ConcreteColleague1 colleague1;
    private ConcreteColleague2 colleague2;
     public void setColleague1(ConcreteColleague1 colleague1) {
        this.colleague1 = colleague1;
    }
     public void setColleague2(ConcreteColleague2 colleague2) {
        this.colleague2 = colleague2;
    }
     @Override
    public void send(String message, Colleague colleague) {
        if (colleague == colleague1) {
            colleague2.receive(message);
        } else {
            colleague1.receive(message);
        }
    }
}
 public class MediatorPatternDemo {
    public static void main(String[] args) {
        ConcreteMediator mediator = new ConcreteMediator();
         ConcreteColleague1 colleague1 = new ConcreteColleague1(mediator);
        ConcreteColleague2 colleague2 = new ConcreteColleague2(mediator);
         mediator.setColleague1(colleague1);
        mediator.setColleague2(colleague2);
         colleague1.send("Hello, Colleague2.");
        colleague2.send("Hello, Colleague1.");
    }
}