【设计模式】——中介者模式（22）

柔情只为你懂 2023-06-24 06:28 4阅读 0赞

一、定义

中介者模式用一个中介对象来封装一些列的对象交互。

二、框架运用

java.util.Timer中就使用了中介者模式的思想

三、实战

1、执行类

public abstract class AbstractClass {
        protected Mediator mediator;
    
        public AbstractClass(Mediator mediator) {
            this.mediator = mediator;
        }
    
        public abstract void send(String msg);
    
        public abstract void notify(String msg);
    }
    
    
    public class AbstractClassA extends AbstractClass {
        public AbstractClassA(Mediator mediator) {
            super(mediator);
        }
    
        @Override
        public void send(String msg) {
            mediator.send(msg, this);
        }
    
        @Override
        public void notify(String msg) {
            System.out.println("AbstractClassA======="+msg);
        }
    }
    
    
    public class AbstractClassB extends AbstractClass {
        public AbstractClassB(Mediator mediator) {
            super(mediator);
        }
    
        @Override
        public void send(String msg) {
            mediator.send(msg, this);
        }
    
        @Override
        public void notify(String msg) {
            System.out.println("AbstractClassB======="+msg);
        }
    }

2、中介类

public interface Mediator {
        void send(String msg,AbstractClass abstractClass);
    }
    
    
    public class ConcreteMediator implements Mediator {
        private AbstractClassA abstractClassA;
        private AbstractClassB abstractClassB;
    
        public void setAbstractClassA(AbstractClassA abstractClassA) {
            this.abstractClassA = abstractClassA;
        }
    
        public void setAbstractClassB(AbstractClassB abstractClassB) {
            this.abstractClassB = abstractClassB;
        }
    
        @Override
        public void send(String msg, AbstractClass abstractClass) {
            if (null != abstractClass) {
                if (null != abstractClassA && abstractClass == abstractClassA) {
                    abstractClassA.notify(msg);
                }
                if (null != abstractClassB && abstractClass == abstractClassB) {
                    abstractClass.notify(msg);
                }
            }
        }
    }

3、运行和结果

public class Client {
        public static void main(String[] args) {
            ConcreteMediator mediator = new ConcreteMediator();
    
            AbstractClassA abstractClassA = new AbstractClassA(mediator);
            AbstractClassB abstractClassB = new AbstractClassB(mediator);
    
            mediator.setAbstractClassA(abstractClassA);
            mediator.setAbstractClassB(abstractClassB);
    
            abstractClassA.send("做A应该做的事");
            abstractClassB.send("做A应该做的事");
        }
    }
    
    
    Connected to the target VM, address: '127.0.0.1:63455', transport: 'socket'
    AbstractClassA=======做A应该做的事
    AbstractClassB=======做A应该做的事
    Disconnected from the target VM, address: '127.0.0.1:63455', transport: 'socket'