设计模式----中介者模式（demiator pattern）

AbstractMediator.java代码如下：

package com.designPattern.mediator;

public abstract class AbstractMediator {

	protected Purchase purchase;
	protected Sale sale;
	protected Stock stock;
	
	public AbstractMediator(){
		purchase = new Purchase(this);
		sale = new Sale(this);
		stock = new Stock(this);
	}
	
	public abstract void execute(String str,Object ...objects);
}

Mediator.java代码如下：

package com.designPattern.mediator;

public class Mediator extends AbstractMediator{

	@Override
	public void execute(String str, Object... objects) {
      if(str.equals("purchase")){
    	  this.buyComputer((Integer)objects[0]);
      }else if(str.equals("sale.sell")){
    	  this.sellComputer((Integer)objects[0]);
      }else if(str.equals("sale.offsell")){
    	  this.offSell();
      }else if(str.equals("stock.clear")){
    	  this.clearStock();
      }
	}
	
	private void buyComputer(int number){
		int saleStatus = super.sale.getSaleStatus();
		if(saleStatus>80){
			System.out.println("采购IBM电脑："+number+"台");
			super.stock.increase(number);
		}else{
			int buyNumber = number/2;
			System.out.println("采购IBM电脑:"+buyNumber+"台");
		}
	}
	
	private void sellComputer(int number){
		if(super.stock.getStockNumber()<number){
			super.purchase.buyIBMComputer(number);
		}
		super.stock.decrease(number);
	}
	
	private void offSell(){
		System.out.println("折价销售IBM电脑"+stock.getStockNumber()+"台");
	}
	
	private void clearStock(){
		super.sale.offSale();
		super.purchase.refuseBuyIBM();
	}

}

AbstractColleague.java代码如下：

package com.designPattern.mediator;

public abstract class AbstractColleague {
 protected AbstractMediator mediator ;
 
 public AbstractColleague(AbstractMediator mediator){
	 this.mediator = mediator;
 }
}

Purchase.java代码如下：

package com.designPattern.mediator;

public class Purchase extends AbstractColleague{

	public Purchase(AbstractMediator mediator) {
		super(mediator);
	}
	
	public void buyIBMComputer(int number){
		super.mediator.execute("purchase", number);
	}
	
	public void refuseBuyIBM(){
		System.out.println("不再采购IBM电脑");
	}

}

Sale.java代码如下：

package com.designPattern.mediator;

import java.util.Random;

public class Sale extends AbstractColleague{

	public Sale(AbstractMediator mediator) {
		super(mediator);
	}
	
	public void sellIBMComputer(int number){
		super.mediator.execute("sale.sell", number);
		System.out.println("销售IBM电脑"+number+"台");
	}
	
	public int getSaleStatus(){
		Random rand = new Random(System.currentTimeMillis());
		int saleStatus = rand.nextInt(100);
		System.out.println("IBM电脑的销售量为："+saleStatus);
		return saleStatus;
	}
	
	public void  offSale(){
		super.mediator.execute("sale.offsell");
	}

}

Stock.java代码如下：

package com.designPattern.mediator;

public class Stock extends AbstractColleague{

	public Stock(AbstractMediator mediator) {
		super(mediator);
	}
	
	private static int COMPUTER_NUMBER = 100;
	
	public void increase(int number){
		COMPUTER_NUMBER = COMPUTER_NUMBER+number;
		System.out.println("库存数量为："+COMPUTER_NUMBER);
	}
	
	public void decrease(int number){
		COMPUTER_NUMBER = COMPUTER_NUMBER-number;
		System.out.println("库存数量为："+COMPUTER_NUMBER);
	}
	
	public int getStockNumber(){
		return COMPUTER_NUMBER;
	}
	
	public void clearStock(){
		System.out.println("清理存货数量为:"+COMPUTER_NUMBER);
		super.mediator.execute("stock.clear");
	}

}

Client.java代码如下：

package com.designPattern.mediator;

public class Client {
	
	public static void main(String[] args) {
		AbstractMediator mediator = new Mediator();
		System.out.println("---------采购人员采购电脑---------");
		Purchase purchase = new Purchase(mediator);
		purchase.buyIBMComputer(100);
		
		System.out.println("----------销售人员销售IBM电脑-----------");
		Sale sale = new Sale(mediator);
		sale.sellIBMComputer(1);
	
		System.out.println("-----------库房管理人员清库处理--------------");
		Stock stock = new Stock(mediator);
		stock.clearStock();
	}

}

运行结果如下：

---------采购人员采购电脑---------
IBM电脑的销售量为：27
采购IBM电脑:50台
----------销售人员销售IBM电脑-----------
库存数量为：99
销售IBM电脑1台
-----------库房管理人员清库处理--------------
清理存货数量为:99
折价销售IBM电脑99台
不再采购IBM电脑