【设计模式】—— 原型模式Prototype

 1 package com.xingoo.test;
 2 
 3 interface Prototype{
 4     public Object clone();
 5 }
 6 class ConcretePrototype1 implements Prototype{
 7     public Object clone() {
 8         Prototype prototype = new ConcretePrototype1();
 9         return prototype;
10     }
11 }
12 class ConcretePrototype2 implements Prototype{
13     public Object clone(){
14         Prototype prototype = new ConcretePrototype2();
15         return prototype;
16     }
17 }
18 public class Client{
19     public static void main(String[] args){
20         Prototype p1 = new ConcretePrototype1();
21         System.out.println("p1 "+p1);
22         
23         Prototype p2 = new ConcretePrototype2();
24         System.out.println("p2 "+p2);
25         
26         Prototype prototype = (Prototype)p1.clone();
27         System.out.println("prototype "+prototype);
28         prototype = (Prototype)p2.clone();
29         System.out.println("prototype "+prototype);
30     }
31 }

p1 com.xingoo.test.ConcretePrototype1@1fb8ee3
p2 com.xingoo.test.ConcretePrototype2@14318bb
prototype com.xingoo.test.ConcretePrototype1@ca0b6
prototype com.xingoo.test.ConcretePrototype2@10b30a7

  1 package com.xingoo.test1;
  2 
  3 import java.util.HashMap;
  4 import java.util.Map;
  5 /**
  6  * 原型的接口
  7  * @author xingoo
  8  */
  9 interface Prototype{
 10     public Prototype clone();
 11 }
 12 /**
 13  * 具体的实现类1
 14  * @author xingoo
 15  *
 16  */
 17 class ConcretePrototype1 implements Prototype{
 18     public Prototype clone() {
 19         Prototype prototype = new ConcretePrototype1();
 20         return prototype;
 21     }
 22 }
 23 /**
 24  * 具体的实现类2
 25  * @author xingoo
 26  *
 27  */
 28 class ConcretePrototype2 implements Prototype{
 29     public Prototype clone(){
 30         Prototype prototype = new ConcretePrototype2();
 31         return prototype;
 32     }
 33 }
 34 /**
 35  * 原型的管理器
 36  * @author xingoo
 37  *
 38  */
 39 class PrototypeManager{
 40     /**
 41      * 用于保存原型的实例
 42      */
 43     private static Map<String,Prototype> map = new HashMap<String,Prototype>();
 44     /**
 45      * 静态方法创建构造函数，避免外部类调用
 46      */
 47     private PrototypeManager(){
 48     }
 49     /**
 50      * 添加原型
 51      * @param protoName 原型的名字
 52      * @param prototype 原型的实例
 53      */
 54     public synchronized static void setPrototype(String protoName,Prototype prototype){
 55         map.put(protoName, prototype);
 56     }
 57     /**
 58      * 获得原型
 59      * @param protoName 原型的名字
 60      * @return 返回原型的实例
 61      * @throws Exception 如果找不到，则跑出找不到异常
 62      */
 63     public synchronized static Prototype getPrototype(String protoName) throws Exception{
 64         Prototype prototype = map.get(protoName);
 65         if(prototype == null){
 66             throw new Exception("no "+protoName+" in Manager");
 67         }
 68         return prototype;
 69     }
 70     /**
 71      * 从管理器中删除原型的实例
 72      * @param protoName 原型的名字
 73      */
 74     public synchronized static void removedPrototype(String protoName){
 75         map.remove(protoName);
 76     }
 77 }
 78 /**
 79  * 原型的使用者
 80  * @author xingoo
 81  *
 82  */
 83 public class Client {
 84     public static void main(String[] args){
 85         try{
 86             /**
 87              * 创建一种原型的实现，放入管理器中
 88              */
 89             Prototype p1 = new ConcretePrototype1();
 90             System.out.println("p1 "+p1);
 91             PrototypeManager.setPrototype("MyPrototype", p1);
 92             
 93             Prototype prototype1 = PrototypeManager.getPrototype("MyPrototype").clone();
 94             System.out.println("prototype1 "+prototype1);
 95             /**
 96              * 切换成另一种原型的实现，修改管理器中的对象
 97              */
 98             Prototype p2 = new ConcretePrototype1();
 99             System.out.println("p2 "+p2);
100             PrototypeManager.setPrototype("p1", p2);
101             
102             Prototype prototype2 = PrototypeManager.getPrototype("MyPrototype").clone();
103             System.out.println("prototype2 "+prototype2);
104             /**
105              * 注销该原型实现，对象使用后，观察情况
106              */
107             PrototypeManager.removedPrototype("MyPrototype");
108             
109             Prototype prototype3 = PrototypeManager.getPrototype("MyPrototype").clone();
110             System.out.println("prototype3 "+prototype3);
111             
112         }catch(Exception e){
113             e.printStackTrace();
114         }
115     }
116 }

p1 com.xingoo.test1.ConcretePrototype1@116ab4e
prototype1 com.xingoo.test1.ConcretePrototype1@129f3b5
p2 com.xingoo.test1.ConcretePrototype1@13f3045
prototype2 com.xingoo.test1.ConcretePrototype1@17a29a1
java.lang.Exception: no MyPrototype in Manager
    at com.xingoo.test1.PrototypeManager.getPrototype(Client.java:66)
    at com.xingoo.test1.Client.main(Client.java:109)