用一个jsp实现对数据库发访问

<%@ page language="java" import="java.util.*" pageEncoding="gb2312"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<%@ page contentType="text/html; charset=gb2312" %>   
<%@ page language="java" %>   
<%@ page import="com.mysql.jdbc.Driver" %>   
<%@ page import="java.sql.*" %>   
<%   
//驱动程序名   
String driverName="com.mysql.jdbc.Driver";   
//数据库用户名   
String userName="root";   
//密码   
String userPasswd="123";   
//数据库名   
String dbName="zzga";   
//表名   
String tableName="t_device";   
//联结字符串   
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);   
//获得数据结果集合   
ResultSetMetaData rmeta = rs.getMetaData();   
//确定数据集的列数，亦字段数   
int numColumns=rmeta.getColumnCount();   
out.print(" 精度 &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp&nbsp &nbsp");
out.print("纬度&nbsp &nbsp &nbsp &nbsp &nbsp &nbsp&nbsp &nbsp");
out.print("  地址 ");
out.print("<br>");
// 输出每一个数据值     
while(rs.next()) {

out.print(rs.getString(4)+" ");

out.print("|");

out.print(rs.getString(5));
out.print("|");

out.print(rs.getString(3));

out.print("<br>");

}  
out.print("数据库操作成功，恭喜你");   
rs.close();   
statement.close();   
connection.close();   
%>
</html>