中介者模式

中介者模式：使用一个中介对象封装对象与其他对象之间的操作行为，使得原本产生交叉蜘蛛网状的对象关系变成星型关系

优点：降低对象与对象之间的耦合，满足迪米特法则

 

标准类图：

 
 抽象中介者：

public abstract class Mediator {

	protected ConcreteColleague1 concreteColleague1;
	protected ConcreteColleague2 concreteColleague2;

	public ConcreteColleague1 getConcreteColleague1() {
		return concreteColleague1;
	}

	public void setConcreteColleague1(ConcreteColleague1 concreteColleague1) {
		this.concreteColleague1 = concreteColleague1;
	}

	public ConcreteColleague2 getConcreteColleague2() {
		return concreteColleague2;
	}

	public void setConcreteColleague2(ConcreteColleague2 concreteColleague2) {
		this.concreteColleague2 = concreteColleague2;
	}

	public abstract void doSomething1();

	public abstract void doSomething2();

}

 

具体中介者：

public class ConcreteMediator extends Mediator{

	@Override
	public void doSomething1() {
		super.concreteColleague1.doSomething1();
	}

	@Override
	public void doSomething2() {
		super.concreteColleague2.doSomething2();
	}

}

 抽象同事类：

public abstract class Colleague {
	
	protected Mediator mediator;

	public Colleague(Mediator mediator) {
		super();
		this.mediator = mediator;
	}
	
	
}

具体同事类：

public class ConcreteColleague1 extends Colleague{

	public ConcreteColleague1(Mediator mediator) {
		super(mediator);
	}
	
	public void doSomething1(){
		System.out.println("do some thing 1");
	}
	
	public void doSomething2(){
		super.mediator.doSomething2();
	}
}

  

public class ConcreteColleague2 extends Colleague{

	public ConcreteColleague2(Mediator mediator) {
		super(mediator);
	}
	
	public void doSomething2(){
		System.out.println("do some thing 2");
	}
	
	public void doSomething1(){
		super.mediator.doSomething1();
	}

}

 

场景类：

public class Client {
	
	public static void main(String[] args) {
		Mediator mediator = new ConcreteMediator();
		ConcreteColleague1 colleague1 = new ConcreteColleague1(mediator);
		ConcreteColleague2 colleague2 = new ConcreteColleague2(mediator);
		mediator.setConcreteColleague1(colleague1);
		mediator.setConcreteColleague2(colleague2);
		
		colleague1.doSomething2();
		
		colleague2.doSomething1();
	}
	
}