connectionpool.java

Java数据库连接池的应用

package com.hoperun.connectionPool;
/**
 * ConnectionPool
 *@author zhou_chenxi
 */
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class ConnectionPool {
 
    //	 sql--query
	private static final String query_="select * from Userinfo";
	
	/**
	 * Main
	 * @param args
	 * @throws SQLException 
	 */
	public static void main(String[] args) throws SQLException {
        //Create a DBConnectionManager Object
		DBConnectionManager connMgr = DBConnectionManager.getInstance();
		 try {    
             Thread.sleep(9);    
         } catch (InterruptedException e) {
             e.printStackTrace();    
         }
		//Create a connection with this name.
		Connection con1 = connMgr.getConnection("PoolTemp");  
        Connection con2 = connMgr.getConnection("PoolTemp");    
        Connection con3 = connMgr.getConnection("PoolTemp");    
        Connection con4 = connMgr.getConnection("PoolTemp");    
        Connection con5 = connMgr.getConnection("PoolTemp",100000); 
        
        //Some JDBC operations on the table Userinfo.
        ResultSet rs = null;
    	Statement stmt = null;
    	stmt=con1.createStatement();	
		rs=stmt.executeQuery(query_);
		System.out.println("Connection1__The user's info:");
        while(rs.next()){
        	System.out.println(rs.getInt("userid"));
        	System.out.println(rs.getString("username"));
        	System.out.println(rs.getInt("age"));
        	System.out.println(rs.getString("addr"));
           }
        rs.close();
        stmt.close();
        //Put the connection back to the pool
		connMgr.freeConnection("PoolTemp", con1);
		connMgr.freeConnection("PoolTemp", con2);
		connMgr.freeConnection("PoolTemp", con3);
		connMgr.freeConnection("PoolTemp", con4);
		connMgr.freeConnection("PoolTemp", con5);
		
		//Release the pool.
		connMgr.release();

	}
}