数据库
登陆页面
index.jsp
<%@ page language="java" contentType="text/html" pageEncoding="UTF-8"%>
<html>
<head>
<title>www.school.com</title>
</head>
<body>
<h1>登录</h1>
<hr>
<form action="DL.jsp" method="post">
<tr>
<td colspan="2">用户登录</td>
</tr>
<tr>
<td>登录ID：</td>
<td><input type="text" name="id"></td>
</tr>
<tr>
<td>登录密码：</td>
<td><input type="password" name="password"></td>
</tr>
<tr>
<td colspan="2"><input type="submit" value="登录">
</tr>
</table>
</form>
</body>
</html>
判断验证页面 DL.jsp
<%@page import="java.nio.channels.SeekableByteChannel"%> <%@ page language="java" contentType="text/html" pageEncoding="UTF-8"%> <%@ page import="java.sql.*"%> <html> <head> <title>www.school.com</title> </head> <body> <%!public static final String DBDRIVER = "com.mysql.jdbc.Driver"; public static final String DBURL = "jdbc:mysql://localhost:3306/text"; public static final String DBUSER = "root"; public static final String DBPASS = "201906";%> <% Connection conn = null; PreparedStatement pstmt = null; ResultSet rs = null; boolean flag = false; String name = null; %> <% try { Class.forName(DBDRIVER); conn = DriverManager.getConnection(DBURL, DBUSER, DBPASS); String sql = "SELECT name FROM dome WHERE uid=? AND upwd=?"; pstmt = conn.prepareStatement(sql); pstmt.setString(1, request.getParameter("id")); pstmt.setString(2, request.getParameter("password")); rs = pstmt.executeQuery(); if (rs.next()) { name = rs.getString(1); flag = true; } } catch (Exception e) { e.printStackTrace(); } finally { try { if (rs != null) rs.close(); if (pstmt != null) pstmt.close(); if (conn != null) conn.close(); if (flag) { request.getRequestDispatcher("CG.jsp").forward(request, response); } else { response.sendRedirect("YH.jsp"); } } catch (Exception e) { e.printStackTrace(); } } %> </body> </html>>
成功页面
CG.jsp
<%@ page language="java" contentType="text/html" pageEncoding="UTF-8"%>
<html>
<head>
<title>www.school.com</title>
</head>
<body>
<h1>登录成功</h1>
<h1>欢迎来到本页<font color="red">
</body>
</html>
登录失败返回登录页面
YH.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<meta charset="UTF-8">
<meta http-equiv="refresh" content="3;url=index.jsp">
<title>登录失败</title>
<script type="text/javascript">
function info() {
//循环执行,1秒执行一次
window.setInterval("daojishi()", 1000);
}
function daojishi() {
if(document.getElementById("msg").innerHTML!=1){
document.getElementById("msg").innerHTML=document.getElementById("msg").innerHTML-1;
}
}
</script>
</head>
<body "info()">
<h1>用户名或密码错误,</h1><span id="msg"></span><h1>3秒返回登录页面</h1>
</body>
</html>
