登录验证页面
login.html：（完成前端页面的操作）
<html><head><title>用户登录</title><meta http-equiv="content-type" content="text/html; charset=gb2312"></head><script language="javascript">function check(){if (document.all.userName.value == ""){alert("对不起，登录帐号不能为空!");return false;}if (document.all.userPWD.value == ""){alert("对不起，登录密码不能为空!");return false;}return true;}</script> <body><h2>用户登录</h2><hr><form name="form1" method="post" action="chkuser.jsp" onSubmit="return check()">登录帐号：<input type="text" id="userName" name="userName"><br>登录密码：<input type="password" id="userPWD" name="userPWD"><br><input type="submit" name="submit" value="提交"><input type="reset" name="reset" value="重填"></form> </body>
</html>
package test;import java.sql.*;public class DBBean {Connection con = null;Statement stat = null;//更新PreparedStatement pstat = null;//动态更新ResultSet rs = null;//查询//无参数的构造函数public DBBean() {}//取得数据库连接public Connection getCon(){try{//Class.forName("com.mysql.jdbc.Driver").newInstance();//String url = "jdbc:mysql://localhost:3306/userdb?user=root&password=root&useUnicode=true&characterEncoding=gb2312";Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver").newInstance(); Connection con=DriverManager.getConnection("jdbc:sqlserver://localhost:1433;databaseName=userdb","sa","123");//con = DriverManager.getConnection(url);}catch(Exception ex){ex.printStackTrace();}return con; }//执行数据库查询并返回查询结果public ResultSet query(String sql){try{con = getCon();stat = con.createStatement();rs = stat.executeQuery(sql);}catch(Exception ex){ex.printStackTrace();}return rs;}//执行数据库更新public void update(String sql){try{con = getCon();stat = con.createStatement();stat.executeUpdate(sql);}catch(Exception ex){ex.printStackTrace();}}//执行数据库更新public void update(String sql,String[] args){try{con = getCon();pstat = con.prepareStatement(sql);for (int i=0;i<args.length;i++){pstat.setString(i+1,args[i]);}pstat.executeUpdate();}catch(Exception ex){ex.printStackTrace();}}//关闭数据库连接public void close(){try{if (rs != null)rs.close();if (stat != null)stat.close();if (pstat != null)pstat.close();if (con != null)con.close();}catch(Exception ex){ex.printStackTrace();} } }
package test;（保存用户的信息）public class UserBean {//属性名称与表单元素相同时，可实现自省String userName = null;String userPWD = null;boolean logined = false;//无参数的构造方法public UserBean() {}//读取userName属性public String getUserName() {return userName;}//设置userName属性public void setUserName(String userName) {this.userName = userName;}//读取userPWD属性public String getUserPWD() {return userPWD;}//设置userPWD属性public void setUserPWD(String userPWD) {this.userPWD = userPWD;}//读取logined属性public boolean isLogined() {return logined;}//设置logined属性public void setLogined(boolean logined) {this.logined = logined;}}
<%@ page language="java" import="java.util.*" pageEncoding="gb2312"%>
<%@ page import="java.sql.*"%>
<%@ page import="test.DBBean"%>
<%@ page import="test.UserBean"%><jsp:useBean id="myDBbean" class="test.DBBean"></jsp:useBean><jsp:useBean id="user" class="test.UserBean" scope="session"></jsp:useBean>
<jsp:setProperty name="user" property="*" /><html><head><title>用户登录验证</title></head><body><h2>用户登录验证</h2><hr><%//user对象中的userName和userPWD是通过自省完成赋值的String userName = user.getUserName();String userPWD = user.getUserPWD();String sql = "select * from user1 where userName='"+userName+"' and userPwd='"+userPWD+"'";if (user.isLogined()){out.println("您已经登录过了!");}else{ResultSet rs = myDBbean.query(sql);if (rs.next()){user.setLogined(true);out.println("恭喜您登录成功!");}else{user.setLogined(false);out.println("对不起，您的帐号或密码不正确!");} } %></body>
</html>