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用servlet校验密码2

news 来源：原创 2024/5/19 2:38:42

一.HTML：

 1 <!DOCTYPE html>
 2 <html>
 3 <head>
 4 <meta charset="UTF-8">
 5 <title>西南石油大学电子邮件系统</title>
 6 <link rel="stylesheet" type="text/css" href="css/style.css">
 7 <script type="text/javascript" src="js/login.js"></script>
 8 </head>
 9 
10 <body>
11 
12     <div class="top">
13         <div class="r1">
14             <div class="r2">
15                 <div class="logo"></div>
16             </div>
17             <a href="" target="" class="help">帮助</a>
18         </div>
19     </div>
20 
21     <div class="content">
22         <div class="loginBar">
23             <div class="box">
24                 <div class="tab">
25                     账号登录
26                     <div class="dragbar"></div>
27                 </div>
28             </div>
29             <div class="boxc">
30                 <div style="height: 10px;"></div>
31                 <div style="margin-left: 42px; width: 270px; height: 30px;">
32                     <div class="hh" id="hd">用户登录</div>
33                 </div>
34                 <form method="post" onsubmit="return ajax()"  >
35                 <input type="text" class="text" name="username" id="username" style="ime-mode: disabled" _autocomplete="off" placeholder="用户名" />
36                     <input type="password" class="text" name="password" id="password" _autocomplete="off" placeholder="密码" />
37                     <div style="height: 10px;"></div>
38                     <div class="bl">
39                         <span style="float: left;"> <font style="color: red; font-family: 宋体; clear: both;">学生选择@stu.swpu.edu.cn</font>
40                         </span> <span style="float: right;"> <a href="" style="outline: none; color: #999;">忘记密码</a>
41                         </span>
42                     </div>
43                     <input type="submit" class="btn" value="登 录" style="background: url(img/login_btn.jpg)" />
44                 </form>
45 
46             </div>
47         </div>
48     </div>
49 
50     <div class="bottom">西南石油大学</div>
51 
52 </body>
53 </html>

View Code

二.JS:

 1 //创建Ajax对象，不同浏览器有不同的创建方法，其实本函数就是一个简单的new语句而已。  
 2           function createXMLHttpRequest() {
 3             var XMLHttpRequest1;
 4             if (window.XMLHttpRequest) {
 5               XMLHttpRequest_test = new XMLHttpRequest();
 6             } else if (window.ActiveXObject) {
 7               try {
 8                 XMLHttpRequest_test = new ActiveXObject("Msxml2.XMLHTTP");
 9               } catch (e) {
10                 XMLHttpRequest_test = new ActiveXObject("Microsoft.XMLHTTP");
11               }
12             }
13             return XMLHttpRequest_test;
14           }
15  
16           function ajax() {
17             var un=document.getElementById("username").value;
18             var pw=document.getElementById("password").value;
19             var XMLHttpRequest_test = createXMLHttpRequest();
20             //指明相应页面  
21             var url = "LoginServlet";
22             XMLHttpRequest_test.open("POST", url, true);
23             //请求头，保证不乱码  
24             XMLHttpRequest_test.setRequestHeader("Content-Type",
25                 "application/x-www-form-urlencoded");
26             //将两个参数传到servlet
27             XMLHttpRequest_test.send("userName=" +un+ "&passWord=" + pw);
28 
29             //处理从servlet返回的结果
30             XMLHttpRequest_test.onreadystatechange = function() {
31               //这个4代表已经发送完毕之后  
32               if (XMLHttpRequest_test.readyState == 4) {
33                 //200代表正确收到了返回结果  
34                 if (XMLHttpRequest_test.status == 200) {
35                   //弹出返回结果  
36                   //alert(XMLHttpRequest_test.responseText);
37                   var result=XMLHttpRequest_test.responseText;
38                   if(result=="1"){
39                       //登陆成功
40                       alert("登陆成功!您好:"+un+"您的密码为:"+pw);
41 
42                   }else if(result=="2"){
43                       //更换class
44                     var hh = document.getElementById("hd");
45                       hh.className="msg";
46                       hh.innerText = "用户名或密码不能为空";
47 
48                   }else{
49                       //更换class
50                     var hh = document.getElementById("hd");
51                       hh.className="msg";
52                       hh.innerText = "用户名或密码错误";
53                   }
54                 } else {
55                   //如果不能正常接受结果，你肯定是断网，或者我的服务器关掉了。  
56                   alert("网络连接中断！");
57                 }
58               }
59             }
60                 return false;//阻止提交，也就是防止原页面刷新导致修改的界面一闪而过
61           }

View Code

三.servlet:

  1 package com.swpu;
  2 
  3 import java.io.IOException;
  4 import java.io.PrintWriter;
  5 import java.sql.Connection;
  6 import java.sql.DriverManager;
  7 import java.sql.ResultSet;
  8 import java.sql.Statement;
  9 
 10 import javax.servlet.ServletException;
 11 import javax.servlet.annotation.WebServlet;
 12 import javax.servlet.http.HttpServlet;
 13 import javax.servlet.http.HttpServletRequest;
 14 import javax.servlet.http.HttpServletResponse;
 15 
 16 /**
 17  * Servlet implementation class LoginServlet
 18  */
 19 @WebServlet("/LoginServlet")
 20 public class LoginServlet extends HttpServlet {
 21     private static final long serialVersionUID = 1L;
 22     private String User;
 23     private String Password;
 24     
 25     String sql=null;
 26     Connection conn=null;
 27     Statement stmt=null;
 28     ResultSet rs=null;
 29     
 30     boolean isLoing=false;
 31        
 32     /**
 33      * @see HttpServlet#HttpServlet()
 34      */
 35     public LoginServlet() {
 36         super();
 37         // TODO Auto-generated constructor stub
 38     }
 39 
 40     /**
 41      * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
 42      */
 43     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 44         // TODO Auto-generated method stub
 45         response.getWriter().append("Served at: ").append(request.getContextPath());
 46     }
 47 
 48     /**
 49      * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
 50      */
 51     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 52         // TODO Auto-generated method stub
 53         response.setContentType("text/html;charset=UTF-8");
 54         response.setCharacterEncoding("utf-8");
 55         PrintWriter out=response.getWriter();
 56         //获取参数
 57         User=request.getParameter("userName");
 58         Password=request.getParameter("passWord");
 59         
 60         //连接数据库检测用户名和密码
 61         try {
 62             //连接数据库
 63             DriverManager.registerDriver(new com.mysql.jdbc.Driver());
 64             conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/homework?useUnicode=true&characterEncoding=UTF-8","root","root");
 65             stmt=conn.createStatement();
 66             sql="select password from login_tb where user='"+User+"'";
 67             rs=stmt.executeQuery(sql);
 68             
 69             if(rs.next()) {
 70                 //获取输入用户名的密码进行检验，若与输入的一致则isLogin置为true，反之置false
 71                 String pw=rs.getString("password");
 72                 if (pw.equals(Password)) {
 73                     isLoing=true;
 74                 }else {
 75                     isLoing=false;
 76                 }
 77             }else {
 78                 //若未查询到用户的存在也置为false
 79                 isLoing=false;
 80             }
 81             
 82         } catch (Exception e) {
 83             // TODO: handle exception
 84             e.printStackTrace();
 85         }finally {
 86             try {
 87                 if(rs!=null)
 88                     rs.close();
 89                 if(stmt!=null)
 90                     stmt.close();
 91                 if(conn!=null)
 92                     conn.close();
 93             } catch (Exception e2) {
 94                 // TODO: handle exception
 95                 e2.printStackTrace();
 96             }
 97         }
 98 
 99         if(isLoing) {
100             //这个字符串将会在js中被接收
101             //1代表登录成功
102             //2代表用户名或密码为空
103             //3代表用户名或密码错误
104             out.write("1");
105         }else if(User==""||Password==""){
106             out.write("2");
107         }else {
108             out.write("3");
109         }
110             out.close();
111     }
112 
113 }