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。
<%@ 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></title> <style type="text/css"> body{ font-size:13px; font-family:"宋体";} /*全局控制*/ body,form,input,p{ padding:0; margin:0; border:0;} /*重置浏览器的默认样式*/ form{ width:350px; height:250px; padding-top:20px; margin:50px auto; /*使表单在浏览器中居中*/ background:#3aa7ea; /*为表单添加背景颜色*/ border-radius:20px; /*设置圆角边框*/ border:3px solid #4faccb; } p{ margin-top:15px; text-align:center; } p span{ width:40px; display:inline-block; text-align:right; } .num,.pass{ /*对文本框设置共同的宽、高、边框、内边距*/ width:152px; height:18px; border:1px solid #38a1bf; padding:2px 2px 2px 22px; } .num{ /*定义第一个文本框的背景、文本颜色*/ background:url(images/1.jpg) no-repeat 5px center #FFF; color:#999; } .pass{ /*定义第二个文本框的背景*/ background:url(images/2.jpag) no-repeat 5px center #FFF; } .btn01,.btn02{ width:60px; height:25px; border-radius:3px; /*设置圆角边框*/ border:1px solid #6b5d50; margin-left:30px; } .btn01{ background:#3aa7ea;} /*设置第一个按钮的背景色*/ </style> </head> <body> <form action="dologin.jsp" method="post" autocomplete="on"> <p> <span>账号：</span> <input type="text" name="user" class="num" /> </p> <p> <span>密码：</span> <input type="password" name="password" class="pass"/> </p> <p><span>验证码</span><input type="text" name="code"/>qwer</p> <p> <input type="submit" class="btn01" value="登录"/> </p> </form> </body> </html>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <%@ page import="java.sql.*" %> <% 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 'dologin.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 Name = request.getParameter("user"); //获取输入的用户名 String ps = request.getParameter("password"); // 密码 String code = request.getParameter("code"); //验证码 Name.trim(); //去空格 ps.trim(); PreparedStatement pre = null; Connection con =null; Statement sql; ResultSet rs; request.setCharacterEncoding("utf-8"); try{ Class.forName("com.mysql.jdbc.Driver"); }catch(Exception e){ out.print("<h1>加载错误"+e); } String user = "root"; String password="root"; con = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/test",user,password); try{ sql = con.createStatement(); String SQLL = "select * from user where uname=? and upwd=?"; pre=con.prepareStatement(SQLL); pre.setString(1,Name); pre.setString(2,ps); rs = pre.executeQuery(); if(rs.next()){ String na = rs.getString(2); session.setAttribute("uname",na); response.sendRedirect("welcome.jsp"); }else{ %> <script > //弹窗提示 alert('输入密码或用户名错误'); </script> <% response.sendRedirect("index.jsp"); } }catch(SQLException e){ out.print("<h1>查询错误"+e); } %> </body> </html>
<%@ 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 'welcome.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> 欢迎<%=session.getAttribute("uname") %>！ </body> </html>