jsp程序和数据库的连接为什么老出错？

               <%@ page language="java" import="java.util.*,java.sql.*" pageEncoding="gbk"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'mysql.jsp' starting page</title>
    
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">    
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->  </head>
  
  <body>
   
<%
String driverName="com.mysql.jdbc.Driver";
String userName="root";
String userPasswd="root";
String dbName="mysql";
String tableName="lhl";
String url="jdbc:mysql://localhost/"+dbName+"?user="+userName+"&password="+userPasswd;
Class.forName("com.mysql.jdbc.Driver").newInstance();
Connection connection=DriverManager.getConnection(url);
Statement statement = connection.createStatement();
String sql="SELECT * FROM "+tableName;
ResultSet rs = statement.executeQuery(sql);
ResultSetMetaData rmeta = rs.getMetaData();
int numColumns=rmeta.getColumnCount();
out.print(" | ");
out.print("name");
out.print(" | ");
out.print("password");
out.print("<br>");
while(rs.next()) {
out.print(rs.getString(1)+" ");
out.print("|");
out.print(rs.getString(2));
out.print("<br>");
}
out.print("<br>");
out.print("数据库操作成功，恭喜你");
rs.close();
statement.close();
connection.close();
%>
  </body>
</html>