第六周作业

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。

 1 <%@ page language="java" import="java.util.*" contentType="text/html;charset=utf-8"%>
 2 <html>
 3 <head>
 4 <title>
 5 用户登录
 6 </title>
 7 </head>
 8 <body bgcolor="#e3e3e3">
 9 <center>
10 <form action="check.jsp" method="post">
11 <table>
12   <caption>用户登录</caption>
13   <tr><td>用户名:</td><td><input type="text" name="username" size="20"/></td></tr>
14   <tr><td>密码:</td><td><input type="text" name="pwd" size="20"/></td></tr>
15   <tr><td><input type="submit" value="登录"/><td><input type="reset" value="重置"/>
16   </table>
17 </form>
18   如果您还没有注册，请单击<a href="register.jsp">这里</a>注册！
19 </body>
20 </center>
21 </html>

 1 <%@ page language="java" import="java.util.*" contentType="text/html;charset=utf-8"%>
 2 <%
 3 String path = request.getContextPath();
 4 String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
 5 %>
 6  
 7 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
 8 <html>
 9   <head>
10     <base href="<%=basePath%>">
11     
12     <title>注册页面</title>
13     
14     <meta http-equiv="pragma" content="no-cache">
15     <meta http-equiv="cache-control" content="no-cache">
16     <meta http-equiv="expires" content="0">    
17     <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
18     <meta http-equiv="description" content="This is my page">
19     <!--
20     <link rel="stylesheet" type="text/css" href="styles.css">
21     -->
22 <script language="javascript">  
23 function isValid(form)  
24 {  
25 if (form.username.value=="")  
26  {  
27  alert("用户名不能为空");  
28  return false;  
29  }  
30 if (form.pwd.value!=form.pwd2.value)  
31 {  
32 alert("两次输入的密码不同！");  
33 return false;  
34 }  
35 else  if (form.pwd.value=="")  
36 {  
37 alert("用户密码不能为空！");  
38 return false;  
39 }  
40 else return true;  
41 }  
42 </script>  
43 </head>
44  
45   <body>
46   <center>
47    <body bgcolor="#e3e3e3">
48   <h2>用户注册</h2>
49   <form action="check2.jsp" method="post" onSubmit="return isValid(this);">
50 <table>
51   <tr><td>用户名:</td><td><input type="text" name="username" size="20"/></td></tr>
52   <tr><td>输入密码:</td><td><input type="text" name="pwd" size="20"/></td></tr>
53   <tr><td>再次确认密码:</td><td><input type="text"name="pwd2" size="20"/></td><tr>
54   <tr><td><input type="submit" value="注册"/><td><input type="reset" value="重置"/>
55   </table>
56 </form>
57   </center>
58    <br>
59   </body>
60 </html>

check.jsp(判断用户登录）

 1 <%@ page language="java" import="java.sql.*" contentType="text/html;charset=utf-8"%>
 2 <%
 3 String path = request.getContextPath();
 4 String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
 5 %>
 6 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
 7 <html>
 8   <head>
 9     <base href="<%=basePath%>">
10     <title>My JSP 'check.jsp' starting page</title>
11     <meta http-equiv="pragma" content="no-cache">
12     <meta http-equiv="cache-control" content="no-cache">
13     <meta http-equiv="expires" content="0">    
14     <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
15     <meta http-equiv="description" content="This is my page">
16     <!--
17     <link rel="stylesheet" type="text/css" href="styles.css">
18     -->
19  </head>
20   <body>
21 <%
22    request.setCharacterEncoding("utf-8");
23    String users=request.getParameter("username");
24    String pass=request.getParameter("pwd");
25    boolean flag=false;
26    PreparedStatement sql=null;  
27    ResultSet rs=null;
28    Connection conn=null;
29 %>
30  
31 <% 
32     String driver = "com.mysql.jdbc.Driver";  
33     String url = "jdbc:mysql://127.0.0.1:3307/login";  
34     String use = "root";   
35     String password = "960404";  
36     Class.forName(driver);  
37     conn= DriverManager.getConnection(url,use,password);  
38     sql =conn.prepareStatement("select * from student where username=? and password=?");
39     sql.setString(1,users);
40     sql.setString(2,pass);
41     rs=sql.executeQuery();
42     if (rs.next()) {  
43     flag=true;
44      }
45    rs.close();
46    sql.close();
47    conn.close();
48   %>
49 <!-- 判断是否是正确的登录用户 -->
50 <% if (flag==true){ %>
51 <jsp:forward page="show.jsp"/>
52 <%} 
53 else
54 if (flag==false){
55 %>
56 <jsp:forward page="login_fali.jsp"/>
57 <%} %>
58 </body>
59 </html>

check2.jsp（判断用户注册）

 1 <%@ page language="java" import="java.sql.*" contentType="text/html;charset=utf-8"%>
 2 <%
 3 String path = request.getContextPath();
 4 String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
 5 %>
 6  
 7 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
 8 <html>
 9   <head>
10     <base href="<%=basePath%>">
11     
12     <title>检验注册页面</title>
13     <meta http-equiv="pragma" content="no-cache">
14     <meta http-equiv="cache-control" content="no-cache">
15     <meta http-equiv="expires" content="0">    
16     <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
17     <meta http-equiv="description" content="This is my page">
18     <!--
19     <link rel="stylesheet" type="text/css" href="styles.css">
20     -->
21  
22   </head>
23   
24   <body>
25     <br>
26    <%
27    request.setCharacterEncoding("utf-8");
28    String users=request.getParameter("username");
29    String pass=request.getParameter("pwd");
30    %>
31    <% 
32     String driver = "com.mysql.jdbc.Driver";  
33     String url = "jdbc:mysql://127.0.0.1:3307/login";  
34     String use = "root";   
35     String password = "960404";  
36     Class.forName(driver);  
37     Connection conn= DriverManager.getConnection(url,use,password);  
38     PreparedStatement sql =conn.prepareStatement("insert into student(username,password)values(?,?)");
39     sql.setString(1,users);
40     sql.setString(2,pass); 
41     int rtn=sql.executeUpdate();
42     sql.close();
43     conn.close();
44     %>
45     
46   </body>
47 </html>

show.jsp(登录成功)

 1 <%@ page language="java" import="java.util.*" contentType="text/html;charset=utf-8"%>
 2 <%
 3 String path = request.getContextPath();
 4 String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
 5 %>
 6  
 7 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
 8 <html>
 9   <head>
10     <base href="<%=basePath%>">
11     <title>登录成功</title>
12     <meta http-equiv="pragma" content="no-cache">
13     <meta http-equiv="cache-control" content="no-cache">
14     <meta http-equiv="expires" content="0">    
15     <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
16     <meta http-equiv="description" content="This is my page">
17     <!--
18     <link rel="stylesheet" type="text/css" href="styles.css">
19     -->
20  
21   </head>
22   
23   <body>
24    登录成功. <br>
25   </body>
26 </html>

login_fail.jsp(注意还是要跳转回原来的登录页面的）

 1 <%@ page language="java" import="java.sql.*" contentType="text/html;charset=utf-8"%>
 2 <%
 3 String path = request.getContextPath();
 4 String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
 5 %>
 6  
 7 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
 8 <html>
 9   <head>
10     <base href="<%=basePath%>">
11     
12     <title>登录失败</title>
13     
14     <meta http-equiv="pragma" content="no-cache">
15     <meta http-equiv="cache-control" content="no-cache">
16     <meta http-equiv="expires" content="0">    
17     <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
18     <meta http-equiv="description" content="This is my page">
19     <!--
20     <link rel="stylesheet" type="text/css" href="styles.css">
21     -->
22  
23   </head>
24   
25   <body>
26   <% out.println("登录失败");%> 
27   <% response.setHeader("refresh","5;url=login.jsp");%>
28   </body>
29 </html>