jsp 获得post数据 结合mysql例子

jsp文件源码如下：

<%@page language="java" pageEncoding="gb2312"%>

<%@page import="java.util.*"%>
<%@page import="com.mysql.jdbc.Driver"%>
<%@page import="java.sql.*"%>
<%@page import="com.mysql.jdbc.ResultSetMetaData"%>



<%
String post_username = request.getParameter("username");
String post_password = request.getParameter("password");
boolean match_flag = false;
String result= null;
%>

<%
String path = request.getContextPath();
String basePath = request.getScheme() + "://"
+ request.getServerName() + ":" + request.getServerPort()
+ path + "/";

/** 链接数据库参数 **/
String driverName = "com.mysql.jdbc.Driver"; //驱动名称
String DBUser = "tag"; //mysql用户名
String DBPasswd = "tag"; //mysql密码
String DBName = "tagproject"; //数据库名

//数据库完整链接地址
String connUrl = "jdbc:mysql://localhost:3306/" + DBName + "?user="
+ DBUser + "&password=" + DBPasswd;

//加载数据库驱动
Class.forName(driverName).newInstance();

//链接数据库并保存到 conn 变量中
Connection conn = DriverManager.getConnection(connUrl);

//申明～？
Statement stmt = conn.createStatement();

//设置字符集
stmt.executeQuery("SET NAMES UTF8");

//要执行的 sql 查询
//String sql = "SELECT idsend,numbersend,timesend,contentsend FROM sendmessage ORDER BY add_time DESC LIMIT 15";
String sql = "SELECT username,password FROM user";

//取得结果
ResultSet rs = stmt.executeQuery(sql);
%>




"post_username" = <%=post_username%>;//在页面中显示出post数据中的username参数
"post_password" = <%=post_password%>;
<p>

<%
/** 打印结果 **/
while (rs.next()) {

%>
db username=
<%=rs.getString("username") %>
;
db password=
<%=rs.getString("password") %>
;


<%
if( (rs.getString("username").equals(post_username) ) && (rs.getString("password").equals(post_password)) )
{



%>

//找到匹配
<%
break;
}
%>

<%
}
%>

<%
if(!match_flag)
{

%>
//不匹配
<%
}
%>

<%
/** 关闭连接 **/
conn.close();
stmt.close();
rs.close();
%>