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。
//连接数据库
1 package session; 2 3 import java.sql.Connection; 4 import java.sql.DriverManager; 5 import java.sql.PreparedStatement; 6 import java.sql.ResultSet; 7 import java.sql.SQLException; 8 9 10 public class Datalink { 11 12 13 //获取连接 14 protected Connection getConnection(){ 15 Connection conn=null; 16 try { 17 Class.forName("com.mysql.jdbc.Driver"); 18 // 2.建立连接 19 conn = DriverManager.getConnection( 20 "jdbc:mysql://localhost:3306/mysql", "root", "root"); 21 } catch (Exception e) { 22 e.printStackTrace(); 23 } 24 return conn; 25 } 26 27 28 //关闭连接 29 protected void closeAll(Connection con,PreparedStatement ps,ResultSet rs){ 30 try { 31 if(rs != null) 32 rs.close(); 33 if(ps != null) 34 ps.close(); 35 if(con != null) 36 con.close(); 37 38 } catch (SQLException e) { 39 e.printStackTrace(); 40 } 41 } 42 43 }
1 <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> 2 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 3 <html> 4 <head> 5 <title>用户登录</title> 6 </head> 7 <body> 8 <form name="form1" method="post" action="dologin.jsp"> 9 用户名： 10 <input type="text" name="userName"> 11 密码： 12 <input type="password" name="pwd"> 13 <input type="submit" value="登录"> 14 </form> 15 </body> 16 </html>
1 <%@ page contentType="text/html;charset=UTF-8" language="java"%> 2 <html> 3 <head> 4 <title>Title</title> 5 </head> 6 <body> 7 <% 8 String uname = request.getParameter("username"); 9 String upwd = request.getParameter("password"); 10 11 String realUname = ""; 12 String reaslPassword = ""; 13 14 Class.forName("com.mysql.jdbc.Driver"); 15 16 Connection connection = DriverManager.getConnection( 17 "jdbc:mysql://localhost:3306/mysql", "root", "root"); 18 19 PreparedStatement preparedStatement = connection 20 .prepareStatement("SELECT * FROM dl where uname = ?"); 21 preparedStatement.setString(1, uname); 22 23 ResultSet rs = null; 24 try { 25 rs = preparedStatement.executeQuery(); 26 } catch (SQLException e) { 27 e.printStackTrace(); 28 } 29 30 while (rs.next()) { 31 realUname = rs.getString("uname"); 32 reaslPassword = rs.getString("upwd"); 33 } 34 35 if (uname.equals(realUname) && upwd.equals(reaslPassword) 36 && inputVcode.equals(inputVcode)) { 37 HttpSession httpSession = request.getSession(); 38 httpSession.setAttribute("username", uname); 39 httpSession.setAttribute("password", upwd); 40 response.sendRedirect("welcome.jsp"); 41 } else { 42 response.sendRedirect("index.jsp"); 43 } 44 %> 45 </body> 46 </html>
1 <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> 2 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 3 <html> 4 <head> 5 <title>session</title> 6 </head> 7 8 <body> 9 <% 10 String uname = (String) session.getAttribute("uname"); 11 if (uname == null) { 12 response.sendRedirect("index.jsp"); 13 } 14 %> 15 欢迎您！<%=uname%> 16 </body> 17 </html>
