设计模式20-中介者模式

最新推荐文章于 2024-10-04 13:44:09 发布

bobshute

最新推荐文章于 2024-10-04 13:44:09 发布

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分类专栏：总结架构设计文章标签：架构设计模式

本文链接：https://blog.youkuaiyun.com/bobshute/article/details/100943848

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1.场景问题解决

1.1 场景描述

智慧房屋公司的产品：
闹钟、咖啡机、电视机、窗帘等

思考如何设计：
各对象有几种状态改变
相互作用如何

1.2 OO设计

1.3 需求变动

1.4 带来问题

2.用设计模式改进

2.1 分析

2.2 重新设计

[外链图片转存失败(img-ik9VrvMn-1568733708520)(https://raw.githubusercontent.com/bobshute/public/master/imgs/csdn/%E8%AE%BE%E8%AE%A1%E6%A8%A1%E5%BC%8F/20%E4%B8%AD%E4%BB%8B%E8%80%85%E6%A8%A1%E5%BC%8F-2.png)]

2.3 源码

vo 该package为同僚相关对象
- Colleague 同僚,抽象父类
- Alarm 闹钟继承Colleague
- CoffeeMachine 咖啡机继承Colleague
- Curtains 窗帘继承Colleague
- TV 电视继承Colleague

public abstract class Colleague {
	private Mediator mediator;
	public String name;

	public Colleague(Mediator mediator, String name) {
		this.mediator = mediator;
		this.name = name;
	}

	public Mediator GetMediator() {
		return this.mediator;
	}

	public abstract void SendMessage(int stateChange);
}



public class Alarm extends Colleague {

	public Alarm(Mediator mediator, String name) {
		super(mediator, name);
		mediator.Register(name, this);
	}

	public void SendAlarm(int stateChange) {
		SendMessage(stateChange);
	}

	@Override
	public void SendMessage(int stateChange) {
		this.GetMediator().GetMessage(stateChange, this.name);
	}
}



public class CoffeeMachine extends Colleague {

	public CoffeeMachine(Mediator mediator, String name) {
		super(mediator, name);
		mediator.Register(name, this);
	}

	@Override
	public void SendMessage(int stateChange) {
		this.GetMediator().GetMessage(stateChange, this.name);
	}

	public void StartCoffee() {
		System.out.println("It's time to startcoffee!");
	}

	public void FinishCoffee() {
		System.out.println("After 5 minutes!");
		System.out.println("Coffee is ok!");
		SendMessage(0);
	}
}



public class Curtains extends Colleague {

	public Curtains(Mediator mediator, String name) {
		super(mediator, name);
		mediator.Register(name, this);
	}

	@Override
	public void SendMessage(int stateChange) {
		this.GetMediator().GetMessage(stateChange, this.name);
	}

	public void UpCurtains() {
		System.out.println("I am holding Up Curtains!");
	}
}



public class TV extends Colleague {

	public TV(Mediator mediator, String name) {
		super(mediator, name);
		mediator.Register(name, this);
	}

	@Override
	public void SendMessage(int stateChange) {
		this.GetMediator().GetMessage(stateChange, this.name);
	}

	public void StartTv() {
		System.out.println("It's time to StartTv!");
	}

	public void StopTv() {
		System.out.println("StopTv!");
	}
}

Mediator 中介者接口
- ConcreteMediator 中介者实现类

public interface Mediator {
	//注册同僚
	public abstract void Register(String colleagueName, Colleague colleague);

	//得到消息后的中介者需要做的操作
	public abstract void GetMessage(int stateChange, String colleagueName);

	public abstract void SendMessage();
}




public class ConcreteMediator implements Mediator {
	//注册超类同僚
	private HashMap<String, Colleague> colleagueMap;
	//注册子类同僚
	private HashMap<String, String> interMap;

	public ConcreteMediator() {
		colleagueMap = new HashMap<String, Colleague>();
		interMap = new HashMap<String, String>();
	}

	@Override
	public void Register(String colleagueName, Colleague colleague) {
		colleagueMap.put(colleagueName, colleague);
		if (colleague instanceof Alarm) {
			interMap.put("Alarm", colleagueName);
		} else if (colleague instanceof CoffeeMachine) {
			interMap.put("CoffeeMachine", colleagueName);
		} else if (colleague instanceof TV) {
			interMap.put("TV", colleagueName);
		} else if (colleague instanceof Curtains) {
			interMap.put("Curtains", colleagueName);
		}

	}

	//得到消息后的中介者需要做的操作
	@Override
	public void GetMessage(int stateChange, String colleagueName) {
		if (colleagueMap.get(colleagueName) instanceof Alarm) {
			if (stateChange == 0) {
				((CoffeeMachine) (colleagueMap.get(interMap.get("CoffeeMachine")))).StartCoffee();
				((TV) (colleagueMap.get(interMap.get("TV")))).StartTv();
			} else if (stateChange == 1) {
				((TV) (colleagueMap.get(interMap.get("TV")))).StopTv();
			}
		} else if (colleagueMap.get(colleagueName) instanceof CoffeeMachine) {
			((Curtains) (colleagueMap.get(interMap.get("Curtains")))).UpCurtains();
		} else if (colleagueMap.get(colleagueName) instanceof TV) {
		} else if (colleagueMap.get(colleagueName) instanceof Curtains) {
		}
	}

	@Override
	public void SendMessage() {
	}
}

MediatorTest 测试类

public class MediatorTest {
	public static void main(String[] args) {
		Mediator mediator = new ConcreteMediator();

		Alarm mAlarm = new Alarm(mediator, "mAlarm");
		CoffeeMachine mCoffeeMachine = new CoffeeMachine(mediator,"mCoffeeMachine");
		Curtains mCurtains = new Curtains(mediator, "mCurtains");
		TV mTV = new TV(mediator, "mTV");

		mAlarm.SendAlarm(0);
		mCoffeeMachine.FinishCoffee();
		mAlarm.SendAlarm(1);
	}
}

3.设计模式总结

3.1 定义

中介者模式：用一个中介对象来封装一系列的对象交互。
中介者使各对象不需要显式地相互引用，从而使其耦合松散，而且可以独立地改变它们之间的交互

3.2 分析思路

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