写了个连接池的类,和大家一起探讨,欢迎交流  [email protected]  
package com.dalong.connectionpool; import java.util.HashMap; import java.util.Vector; import java.sql.Connection; import java.sql.DriverManager; import java.sql.*; /**  * <p>Title: </p>  * <p>Description: test</p>  * <p>Copyright: Copyright (c) 2003</p>  * <p>Company: home</p>  * @author dalong  * @version 1.0  */ 
public class ConnectionPool { 
  //连接池的管理器,首先初始化,仅仅有一个对象,管理连接池   private static HashMap connectionPoolManager=new HashMap();   //没有用过的连接池,用vector实现同步   private static Vector noUseConnectionPool;   //没有用过的连接池   private  static HashMap nowUseConnectionPool; 
  private  static String dbDriver="odbc:jdbc:OdbcJdbcDriver";   private  static String dbUrl="dalong@XX";   private  static String userName="dalong";   private  static String userPassword="dalong"; 
  //默认为100个连接池   private  static int MAX_POOL=100; 
 //singleTon 设计模式   private ConnectionPool(String driver,String url,String name,String password,int max)      throws ClassNotFoundException {       Class.forName(driver);       dbUrl=url;       userName=name;       userPassword=password;       MAX_POOL=max;  }  public static ConnectionPool getConnManagerInstance(String poolName)       throws ClassNotFoundException{      ConnectionPool tempPool=(ConnectionPool)connectionPoolManager.get(poolName);      if(tempPool==null){         tempPool=new ConnectionPool(dbDriver,dbUrl,userName,userPassword,MAX_POOL);         connectionPoolManager.put(poolName,tempPool);         return tempPool;      }else        return tempPool;  } 
 //通过连接池获得真正的链接  public static Connection getConnection() throws java.sql.SQLException{     Connection conn=null;     synchronized(noUseConnectionPool){        if(noUseConnectionPool.size()>0){          conn=(Connection)noUseConnectionPool.firstElement();          noUseConnectionPool.remove(conn);         return conn;        }     }     //如果数据库连接池没有链接了,自己创建一个     if(conn==null){        conn=createConnection(dbDriver,dbUrl,userName,userPassword);     }else if(conn.isClosed()){        nowUseConnectionPool.remove(conn);        conn=createConnection(dbDriver,dbUrl,userName,userPassword);       }     conn.setAutoCommit(false);     nowUseConnectionPool.put(conn,conn);     return conn;  } 
 //如果连接池没有链接了,就需要产生一个链接  private static Connection createConnection(String driver,String url,String user,String password)        throws java.sql.SQLException{      Connection conn=DriverManager.getConnection(url,user,password);      return conn;  }  public static void releaseConnection(Connection conn,boolean isCommit)     throws java.sql.SQLException{     if(isCommit)        conn.commit();     else        conn.rollback();     nowUseConnectionPool.remove(conn);        if(noUseConnectionPool.size() + nowUseConnectionPool.size()<MAX_POOL){           synchronized(noUseConnectionPool){             noUseConnectionPool.add(conn);           }        }else{          conn.close();        }  } 
 public static void main(String[] args) {   //测试模拟10个客户    for (int i = 0; i < 10; i++) {      try {        //xxxx 一般为属性文件读取        ConnectionPool pool = ConnectionPool.getConnManagerInstance("xxxx");        Connection conn = pool.getConnection(); 
     }catch (SQLException ex1) {         //处理异常       }      catch (ClassNotFoundException ex) {         //处理异常      }    }  } }  
 
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