JSP连接MySQL数据库问题

<%@ page contentType="text/html; 
charset=gb2312" language="java" 
 import="java.sql.*"%>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<%//*******************************
**************** 
 JDBC_ODBC连接MySql数据库，不需要设置数据源***********
**********************/  
 //********** 数据库连接代码开始 ******/   
//以下几项请自行修改String server="localhost";        
//MYSQL 服务器的地址String dbname="test";           
 //MYSQL 数据库的名字String user="root";                
//MYSQL 数据库的登录用户名String pass="chfanwsp";            
//MYSQL 数据库的登录密码String port="3306";    
//SQL Server 服务器的端口号，
默认为1433//数据库连接字符串
 String url ="jdbc:mysql://"+server+":"+port+"/"+dbname+"?
user="+user+"&passWord="+pass+"&useUnicode
=true&characterEncoding=GB2312"; 
//加载驱动程序Class.forName("org.gjt.mm.mysql.Driver").newInstance();
//建立连接Connection conn= DriverManager.getConnection(url); 
//创建语句对象Statement stmt=conn.createStatement
(ResultSet.TYPE_SCROLL_SENSITIVE,
ResultSet.CONCUR_UPDATABLE);
// ****     数据库连接代码结束 *******  
  String sql="select * from username";
ResultSet rs=stmt.executeQuery(sql);
//rs.first();while(rs.next()){out.print("用户名:");
out.print(rs.getString("uid")+" 密码:");
out.println(rs.getString("pwd")+"<br>");}
rs.close();stmt.close();conn.close();%>

package conn;    //导入包import java.sql.*;        
//导入数据库操作的类public class DBConnMySql            
//构造方法，初始化{private Connection conn;        
//连接对象private Statement stmt;    
//语句对象private ResultSet rs;    
//结果集对象private String MySqldriver;
//MYSQL Server驱动程序字符串private String MySqlURL; 
//MYSQL Server连接字符串//*********************************
用  org.gjt.mm.mysql.Driver 驱动 
*  该方法取得连接所需各种参数，组成连接字符串，
然后再建立连接*  server;dbname,user,pass,port 
分别表示MYSQL 服务器的地址，
*  数据库，用户名，密码，端口
**********************************/
public Connection getConnToMySql
(String server,String dbname,String user,String pass,String port)
{//MYSQl驱动程序MySqldriver = "org.gjt.mm.mysql.Driver";    
MySqlURL = "jdbc:mysql://";          
//连接字符串一部分try{//完整的连接字符串MySqlURL 
=MySqlURL+server+":"+port+"/"+dbname+"?user=
"+user+"&password="+pass+"&useUnicode
=true&characterEncoding=GB2312"; 
Class.forName(MySqldriver);conn 
= DriverManager.getConnection(MySqlURL);}
catch(Exception e){System.out.println
("操作数据库出错，请仔细检查");
//System.err.println(e.getMessage());}return conn;}    
//关闭数据库连接public void close(){try{//rs.close();
//stmt.close();conn.close();}catch(SQLException 
sqlexception){sqlexception.printStackTrace();}}}

<meta http-equiv="Content-Type" content="text/html; 
charset=gb2312"><%@ page contentType="text/html; 
charset=gb2312" language="java" import="java.sql.*"  %>
<jsp:useBean id="DBConn" scope="page" class="conn.DBConnMySql"/>
<% //以下几项请自行修改String server="localhost";        
//MYSQL 服务器的地址String dbname="test";       
 //MYSQL 数据库的名字String user="root";            
//MYSQL 数据库的登录用户名String pass="chfanwsp";        
//MYSQL 数据库的登录密码String port="3306";           
 //SQL Server 服务器的端口号，默认为1433Connection 
conn=DBConn.getConnToMySql
(server,dbname,user,pass,port);
Statement stmt=conn.createStatement
(ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_READ_ONLY);
String sql="select * from username";
String sql1="insert into username (uid,pwd) values
('梦想年华','梦想年华')";stmt.executeUpdate(sql1);
ResultSet rs=stmt.executeQuery(sql);while(rs.next())
{out.print("用户名:");out.print(rs.getString("uid")+" 密码:");
out.println(rs.getString("pwd")+"<br>");}
//rs.close();//stmt.close();//conn.close();DBConn.close();%>