菜鸟硕枫设计模式系列之18 中介者模式

中介者模式，”中介者“，即在一系列系统交互的过程中，通过第三方的办法使得这些系统不用直接交互，都通过中介来进行。这里简化了系统的关系，但是有可能使得中介成为系统的交互瓶颈。

中介者模式类图：

[img]http://dl.iteye.com/upload/attachment/364831/7c2f273b-1739-35f0-ab6f-0aa7cbb44013.jpg[/img]


具体实现示例：

package mediatorPattern;

public abstract class Person {

	private String name;
	private String hobby;
	private Mediator mediator;

	public Person(String name,String hobby,Mediator mediator){
		this.setName(name);
		this.setHobby(hobby);
		this.setMediator(mediator);
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getName() {
		return name;
	}

	public void setHobby(String hobby) {
		this.hobby = hobby;
	}

	public String getHobby() {
		return hobby;
	}

	public void setMediator(Mediator mediator) {
		this.mediator = mediator;
	}

	public Mediator getMediator() {
		return mediator;
	}

	public abstract void getPair(Person person);

}

package mediatorPattern;

public class Man extends Person{

	public Man(String name, String hobby, Mediator mediator) {
		super(name, hobby, mediator);
		// TODO Auto-generated constructor stub
	}

	@Override
	public void getPair(Person person) {
		this.getMediator().setMan(this);
		this.getMediator().getPair(person);
	}

}

package mediatorPattern;

public class Woman extends Person{

	public Woman(String name, String hobby, Mediator mediator) {
		super(name, hobby, mediator);
		// TODO Auto-generated constructor stub
	}

	@Override
	public void getPair(Person person) {
		// TODO Auto-generated method stub
		this.getMediator().setWoman(this);
		this.getMediator().getPair(person);
	}

}

中介类：

package mediatorPattern;

public class Mediator {

	private Man man;
	private Woman woman;
	public void setMan(Man man) {
		this.man = man;
	}
	public Man getMan() {
		return man;
	}
	public void setWoman(Woman woman) {
		this.woman = woman;
	}
	public Woman getWoman() {
		return woman;
	}
	public void getPair(Person person){
		if(person instanceof Man)
			this.setMan((Man)person);
		else
			this.setWoman((Woman)person);
		if(man!=null&&woman!=null&&(woman.getHobby().equals(man.getHobby()))){
			System.out.println("A wonderful pair");
		}else if(man!=null&&woman!=null){
			System.out.println("A just so so pair");
		}else{
			System.out.println("Just gays haha");
		}
	}
}

测试类：

package mediatorPattern;

public class MediatorPatternTest {

	public static void main(String[]args){
		Mediator mediator = new Mediator();
		Man man = new Man("lxy","basketball",mediator);
		Woman woman = new Woman("who?","basketball",mediator);
		Man shuofeng = new Man("shuofeng","football",mediator);
		man.getPair(shuofeng);
		man.getPair(woman);
		shuofeng.getPair(woman);
		System.out.println("-----------------");
		woman.getPair(man);
		woman.getPair(shuofeng);
	}
}

说明：man 和 woman通过mediator去gerPair,使得Man和Woman不直接发生关系，这样两个类就在业务上分离了，这是最少知识原则的又一体现，和代理模式有着异曲同工之妙。