定义自己的Connection Pool

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自定义Connection Pool的源代码及用法

1.存储基本的数据库连接Bean

package BSC.pool;

import java.sql. *;

import java.io.Serializable;

 

/**

 * <p>Title: </p>

 * <p>Description: </p>

 * <p>Copyright: Copyright (c) 2003</p>

 * <p>Company: </p>

 * @author unascribed

 * @version 1.0

 */

 

public class ConnBean implements java.io.Serializable {

 

  private Connection conn=null;

  private boolean inuse=false;

  public ConnBean() {

  }

  public ConnBean(Connection con)

  {

    if(con!=null)conn=con;

  }

  public void setConnection(Connection con)

  {

    conn=con;

  }

  public Connection getConnection()

  {

    return conn;

  }

  public void setInuse(boolean inuse)

  {

    this.inuse =inuse;

  }

  public boolean getInuse()

  {

    return inuse;

  }

  public void close()

  {

    try

    {

      conn.close();

    }

    catch(SQLException sqle)

    {

      System.err.println(sqle.getMessage());

    }

  }

}

2. 连接池管理Bean

 

package BSC.pool;

import java.sql. *;

import java.util.*;

import java.lang.InterruptedException;

import java.io.Serializable;

 

import BSC.pool.ConnBean;

/**

 * <p>Title: </p>

 * <p>Description: </p>

 * <p>Copyright: Copyright (c) 2003</p>

 * <p>Company: </p>

 * @author unascribed

 * @version 1.0

 */

 

public class PoolBean  implements java.io.Serializable {

 

  private String driver=null;

  private String url=null;

  private int size=0;

  private String username="";

  private String password="";

  private ConnBean connBean=null;

  private Vector pool=null;

  private String dbType="1";

  public PoolBean() {

  }

  public void setDriver(String d)

  {

    if(d!=null)driver=d;

  }

  public String getDriver()

  {

    return driver;

  }

  public void setURL(String u)

  {

    if(u!=null)url=u;

  }

  public String getURL()

  {

    return url;

  }

  public void setSize(int s)

  {

    if(s>1)size=s;

  }

  public int getSize()

  {

    return size;

  }

  public void setUsername(String un)

  {

    if(un!=null)username=un;

  }

  public String getUsername()

  {

    return username;

  }

  public void setPassword(String pwd)

  {

    if(pwd!=null)password=pwd;

  }

  public String getPassword()

  {

    return password;

  }

  public void setConnBean(ConnBean cb)

  {

    if(cb!=null)connBean=cb;

  }

  public ConnBean getConnBean() throws Exception

  {

    Connection con=getConnection();

    ConnBean cb=new ConnBean(con);

    cb.setInuse(true) ;

    return cb;

 

  }

  private Connection createConnection() throws Exception

  {

    Connection con=null;

    con=DriverManager.getConnection(url,username,password) ;

    return con;

  }

  public synchronized void initializePool() throws Exception

  {

    if(driver==null)

      throw new Exception("没有提供驱动程序名称!");

    if(url==null)

      throw new Exception("没有提供URL!");

    if(size<1)

      throw new Exception("连接池大小不能小于一!");

    try

    {

        // DriverManager.registerDriver(new COM.ibm.db2.jdbc.app.DB2Driver());

         Class.forName(driver).newInstance();

 

      for(int i=0;i<size;i++)

      {

        Connection con=createConnection();

        if(con!=null)

        {

          ConnBean cb=new ConnBean(con);

          addConnection(cb);

 

        }

      }

    }

    catch(Exception e)

    {

     System.err.println(e.getMessage());

     throw new Exception(e.getMessage() );

    }

 

  }

  private void addConnection(ConnBean cb)

 {

   if(pool==null)pool=new Vector(size);

    pool.addElement(cb);

 }

 

 public synchronized void releaseConnection(Connection con)

 {

   for(int i=0;i<pool.size() ;i++)

   {

     ConnBean cb=(ConnBean)pool.elementAt(i);

     if(cb.getConnection() ==con)

     {

       System.err.println("释放第"+i+"个连接");

       cb.setInuse(false);

       break;

     }

   }

 }

 public synchronized Connection getConnection()

 throws Exception

 {

   ConnBean  cb=null;

   for(int i=0;i<pool.size() ;i++)

   {

     cb=(ConnBean)pool.elementAt(i);

     if(cb.getInuse()==false)

     {

       cb.setInuse(true) ;

       Connection con=cb.getConnection();

       if(!con.isClosed()){

         return con;

       }else{

         pool.removeElement(cb);

       }

     }

   }

   try

   {

     Connection con=createConnection();

     cb=new ConnBean(con);

     cb.setInuse(true);

     pool.addElement(cb);

 

   }

   catch(Exception e)

   {

     System.err.println(e.getMessage() );

     throw new Exception(e.getMessage() );

   }

   return cb.getConnection() ;

 }

 

 public synchronized void emptyPool()

 {

  for(int i=0;i<pool.size() ;i++)

  {

    System.err.println("关闭第"+i+"JDBC连接");

    ConnBean cb=(ConnBean)pool.elementAt(i);

    if(cb.getInuse()==false)

          cb.close();

    else

    {

      try

      {

         java.lang.Thread.sleep(20000);

         cb.close();

      }

      catch(InterruptedException ie)

      {

        System.err.println(ie.getMessage());

      }

    }

  }

 }

  public String getDbType() {

    return dbType;

  }

  public void setDbType(String dbType) {

    this.dbType = dbType;

  }

}

3.用法

import java.sql.*;

import BSC.pool.*;

…其他代码

Connection conn=null;

try{

        poolbean = new PoolBean();

        poolbean.setDriver(this.getDriver());

        poolbean.setURL(this.getUrl());

        poolbean.setSize((new Integer(this.getSize())).intValue());

        poolbean.setUsername(this.getUsername());

        poolbean.setPassword(this.getPassword());

        poolbean.initializePool();

        conn=pool.getConnection();

        …其他代码

}catch(Exception e){

        e.printStackTrace();

}finally{

        try{

       if(conn!=null)

           conn.close();

}catch(SQLException sqle){

      sqle.printStackTrace();

 

}

}

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