1.安装MySQL数据库，建立用户表 uid uname upwd 并插入3条数据
2.制作jsp登录页面 login.jsp 提交到dologin.jsp，使用jdbc连数据库，判断输入的用户名密码是否存在
3.如果存在，把用户名保存在SESSION中，跳转到welcome.jsp，welcome.jsp中读取session中的用户名，显示欢迎你xxx
4.若不存在，跳到登录页面。
login.jsp
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <!DOCTYPE HTML > <html> <head> <title>登录界面</title> <!-- <link rel="stylesheet" type="text/css" href="styles.css"> --> <style type="text/css"> .contentArea{450px;position:absolute;top:80px;left:250px;height:500px;} </style> </head> <body style="background:url(images/3.jpg)"> <div class="contentArea"> <p style="font-family:黑体；font-size:56；color：yellow"></p> 登录<br/><br/><br/> <form action="db.jsp" method="post" > ID：<input type="text" name="uid"><br/><br/> 密码：<input type="password" name="upwd"><br/> <br/> 验证码：<img src="number.jsp"/> <input type="text" name="code"/> <br/><br/> <input type="submit" value="登录"><br/><br/><br/><br/> </form> </div> </body > </html>
dologin.jsp
<%@ page contentType="image/jpeg" language="java" import="java.util.*,java.awt.*,java.awt.image.*,javax.imageio.*" pageEncoding="utf-8"%> <% //获取登录的用户名 String name = request.getParameter("uname"); //获取登录密码 String pwd = request.getParameter("upwd"); //判断 if (name.equals("zs") && pwd.equals("123"))//判断字符串是否相等不是等号是eqyals //转发到ok页面 request.getRequestDispatcher("ok.jsp").forward(request,response); else //转发到no页面 request.getRequestDispatcher("login.jsp").forward(request,response); %>
ok.jsp
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <% 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 'index.jsp' starting page</title> <!-- <link rel="stylesheet" type="text/css" href="styles.css"> --> <style type="text/css"> .contentArea{450px;position:absolute;top:150px;left:250px;height:500px;} </style> </head> <body style="background:url(images/3.jpg)"> <div class="contentArea"> <h1 style="color: red">登录成功</h1> </div> </body> </html>
no.jsp
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <% 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 'index.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"> --> <style type="text/css"> .contentArea{450px;position:absolute;top:150px;left:250px;height:500px;} </style> </head> <body style="background:url(images/3.jpg)"> <div class="contentArea"> <h1 style="color: red" >登录失败</h1> <h2>点击重新<a href="login.jsp">登录</a></h2> </div> </body> </html>
db.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/jspwork"; public static final String DBUSER = "root"; public static final String DBPASS = "root";%> <% 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 uname FROM num_one WHERE uid=? AND upwd=?"; pstmt = conn.prepareStatement(sql); pstmt.setString(1, request.getParameter("uid")); pstmt.setString(2, request.getParameter("upwd")); 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.getSession().setAttribute("uname",name); request.getRequestDispatcher("welcome.jsp").forward(request,response); // request.getRequestDispatcher("ok.jsp").forward(request, response); } else { response.sendRedirect("no.jsp"); } } catch (Exception e) { e.printStackTrace(); } } %> </body> </html>
