中介者模式

中介者模式就是在对象之间的关系很复杂时用，名如其人，就像租房的黑中介一样，如果每个房东都拿着很多租房者的信息很麻烦，每个租房者都要拿着很多房东的信息也麻烦，所以需要一个中介来拿着这些信息，租房者只需要发出租房的请求，中介会给你介绍合适的房东，房东只需要提交房屋资料就等着中介的人带着访客看房拿钱就行了，所以租房者和房东都要拿着中介的信息，这个模式不难理解，但是中介会用收中介费，加房租等毒辣手段，所以就是他来包装租房者发的请求，中间处理了一下交给房东，比如房租500，向租房者要1000，给房东400，呵呵。
Mediator 类可以增加很多租房者和房东间的交互。

package com.jerry.design.mediator;


//租房者
abstract class Colleague {
	private Mediator mediator;
	public Mediator getMediator() {
	   return mediator;
	}
	public Colleague(Mediator m) {
	   mediator = m;
	}
	// 租房者发送租房消息
	public abstract void sendMsg();
	// 房东接到看房的消息
	public void getMsg() {
		 System.out.println("Colleague1 要看房");
	}
}

//租房者
class Colleague1 extends Colleague {
	
	public Colleague1(Mediator m) {
	   super(m);
	}

	@Override
	public void sendMsg() {
	   System.out.println("Colleague1 要看房");
	   getMediator().toFangdong(this);
	}

	@Override
	public void getMsg() {		
	}

}
//租房者
class Colleague2 extends Colleague {

	public Colleague2(Mediator m) {
	   super(m);
	}

	public void getMsg(String msg) {
	}

	public void sendMsg() {
	   System.out.println("Colleague2 要看房");
	}
}
//房东
class Colleague3 extends Colleague {

	public Colleague3(Mediator m) {
	   super(m);
	}

	public void getMsg() {
	   System.out.println("Colleague3房东接到了看房消息 ");
	}

	public void sendMsg() {
		System.out.println("Colleague3房东发出了提交资料给中介的消息 ");
	}
}


abstract class Mediator {
	
	public abstract void toFangdong(Colleague sender);

}

class ConcreteMediator extends Mediator {
	private Colleague1 colleague1;
	private Colleague2 colleague2;
	private Colleague3 colleague3;

	@Override
	public void toFangdong(Colleague sender) {
		if(sender!=colleague3){
			colleague3.getMsg();
		}else{
			colleague3.sendMsg();
		}
	}

	public Colleague1 getColleague1() {
		return colleague1;
	}

	public void setColleague1(Colleague1 colleague1) {
		this.colleague1 = colleague1;
	}

	public Colleague2 getColleague2() {
		return colleague2;
	}

	public void setColleague2(Colleague2 colleague2) {
		this.colleague2 = colleague2;
	}

	public Colleague3 getColleague3() {
		return colleague3;
	}

	public void setColleague3(Colleague3 colleague3) {
		this.colleague3 = colleague3;
	}

	 
}

	// 测试类
public class Test {

	public static void main(String[] args) {
	   ConcreteMediator mediator = new ConcreteMediator();
	   Colleague1 colleague1 = new Colleague1(mediator);
	   Colleague2 colleague2 = new Colleague2(mediator);
	   Colleague3 colleague3 = new Colleague3(mediator);
	   
	   mediator.setColleague1(colleague1);
	   mediator.setColleague2(colleague2);
	   mediator.setColleague3(colleague3);

	   mediator.toFangdong(colleague3);
	   mediator.toFangdong(colleague1);
	   mediator.toFangdong(colleague2);
	   
	    
	}
}