对象池模式和代理模式配合使用的例子-白红宇

对象池模式和代理模式配合使用的例子

阅读量：6891 次

发布时间：2019-06-27

本文共 3075 字，大约阅读时间需要 10 分钟。

1、Connection接口

1 package com.xinye.test.pool3;2 3 public interface Connection {4     void set(Object obj);5     void get();6 }

2、Connection实现

1 package com.xinye.test.pool3; 2  3 public class ConnectionImpl implements Connection { 4  5     @Override 6     public void set(Object obj) { 7  8     } 9 10     @Override11     public void get() {12 13     }14 15 }

3、Connection代理类

1 package com.xinye.test.pool3; 2 /** 3  *  4  * @author xinye 5  * 6  */ 7 public class ConnectionProxy implements Connection{ 8     private ReleaseablePoolItem
     
       releaseable = null; 9     public ConnectionProxy(ReleaseablePoolItem
      
        rel){10         this.releaseable = rel;11     }12     @Override13     public void set(Object obj) {14         releaseable.getReference().set(obj);15     }16 17     @Override18     public void get() {19         releaseable.getReference().get();20     }21 22 }

4、连接池

1 package com.xinye.test.pool3; 2  3 public class ConnectionPool { 4     private static PoolManager
     
       manager = new PoolManager
      
       (); 5     private ConnectionPool(){ 6          7     } 8     public static void add(int num){ 9         for(int i = 0;i < num;i++){10             manager.add(new ConnectionImpl());11         }12     } 13     public static Connection getConnection(){14          ReleaseablePoolItem
       
         conn = manager.get();15          if(conn == null){16              return null;17          }18          return new ConnectionProxy(conn);19     }20     21 }

5、池子中放的东西

1 package com.xinye.test.pool3;2 3 public class PoolItem 
     
      {4     public boolean isUse = false;5     public T item;6     public PoolItem(T t){7         this.item = t;8     }9 }

6、释放对象的时候不能再使用

1 package com.xinye.test.pool3; 2 /** 3  *  4  * @author  5  * 6  * @param 
     
       7  */ 8 public class ReleaseablePoolItem 
      
       { 9     public PoolItem
       
         reference;10     public boolean released = false;11     public ReleaseablePoolItem(PoolItem
        
          reference){12         13         this.reference = reference;14         15     }16     public T getReference(){17         if(released){18             throw new RuntimeException("Tried to use reference after it was released");19         }20         return reference.item;21     }22     public void release(){23         released = true;24         reference.isUse = false;25     }26 }

7、池子管理对象

1 package com.xinye.test.pool3; 2  3 import java.util.ArrayList; 4  5 public class PoolManager 
     
       { 6     private ArrayList
      
       
        > list = new ArrayList
        
         
          >(); 7      8     public void add(T t){ 9         list.add(new PoolItem
          
           (t));10 }11 public ReleaseablePoolItem
           
             get(){12 int len = list.size();13 for(int i = 0;i < len;i++){14 PoolItem
            
              item = list.get(i);15 if(item.isUse == false){16 item.isUse = true;17 return new ReleaseablePoolItem
             
              (item);18 }19 }20 return null;21 }22 }