享元模式

 1 package day_12_flyweight;
 2 
 3 /**
 4  * 享元类接口
 5  * @author 余林丰
 6  *
 7  * 2016年10月12日
 8  */
 9 public interface Flyweight {
10     void operation(int extrinsicstate);　　//这里的extrinsicstate就是上面所说的外部状态
11 }

 1 package day_12_flyweight;
 2 
 3 /**
 4  * 具体享元类
 5  * @author 余林丰
 6  *
 7  * 2016年10月12日
 8  */
 9 public class ConcreteFlyweight implements Flyweight {
10 
11     /* (non-Javadoc)
12      * @see day_12_flyweight.Flyweight#operation(int)
13      */
14     @Override
15     public void operation(int extrinsicstate) {
16         System.out.println("博客，账号：" + extrinsicstate);
17     }
18 
19 }

 1 package day_12_flyweight;
 2 
 3 import java.util.HashMap;
 4 
 5 /**
 6  * 享元类工厂
 7  * @author 余林丰
 8  *
 9  * 2016年10月12日
10  */
11 public class FlyweightFactory {
12     private HashMap<String, ConcreteFlyweight> flyweights = new HashMap<String, ConcreteFlyweight>();
13     
14     public FlyweightFactory(){
15         flyweights.put("X", new ConcreteFlyweight());
16         flyweights.put("Y", new ConcreteFlyweight());
17         flyweights.put("Z", new ConcreteFlyweight());
18     }
19     
20     public Flyweight getFlyweight(String key){
21         return ((Flyweight)flyweights.get(key));
22     }
23 }

 1 package day_12_flyweight;
 2 
 3 /**
 4  * 客户端测试
 5  * @author 余林丰
 6  *
 7  * 2016年10月12日
 8  */
 9 public class Client {
10     public static void main(String[] args){
11         int extrinsicstate = 100;        //代码外部状态
12         FlyweightFactory f = new FlyweightFactory();
13         Flyweight fx = f.getFlyweight("X");
14         fx.operation(extrinsicstate);
15         
16         Flyweight fy = f.getFlyweight("Y");
17         fx.operation(--extrinsicstate);
18     }
19     
20 }