jsp登录页面雏形

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 4 <html>
 5 <head>
 6 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 7 <title>欢迎页面</title>
 8 </head>
 9 <body>
10 <%
11 session.invalidate();//销毁session
12 
13 %>
14 
15 <a href="denglu.jsp" >亲，请登录</a>
16 <a href="zhuce.jsp">注册</a>
17 </body>
18 </html>

欢迎界面：

尚未注册，直接登录的时候：

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 4 <html>
 5 <head>
 6 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 7 <title>登录</title>
 8 </head>
 9 <body>
10 <form action="test_denglu.jsp" method="post"> 
11 <table width="300" height="300" border="0" align="center">
12    <tr height="80" align="center">
13        <td colspan="2"><font size="24">OO登录</font></td></tr>
14    <tr height="30">
15        <td width="80" align="right">用户名：</td>                          
16        <td><input type="text" name="username"></td></tr>
17    <tr height="30">
18        <td width="80" align="right"> 密&nbsp;&nbsp;码：</td>
19        <td> <input type="password" name="password"></td></tr>
20        <tr><td height="40" align="center" colspan="2">
21        <input type="submit" value="登录">
22        </td></tr>
23  </table>
24 </form>
25 </body>
26 </html>

进入注册界面：

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 4 <html>
 5 <head>
 6 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 7 <title>注册</title>
 8 </head>
 9 <body>
10 <form action="test_zhuce.jsp" method="post"> 
11 <table width="300" height="300" border="0" align="center">
12    <tr height="80" align="center">
13        <td colspan="2"><font size="24">OO注册</font></td></tr>
14    <tr height="30">
15        <td width="80" align="right">用户名：</td>                          
16        <td><input type="text" name="username"></td></tr>
17    <tr height="30">
18        <td width="80" align="right"> 密&nbsp;&nbsp;码：</td>
19        <td> <input type="password" name="password"></td></tr>
20        <tr><td height="40" align="center" colspan="2">
21        <input type="submit" value="提交">
22        </td></tr>
23  </table>
24 </form>
25 </body>
26 </html>

注册成功，跳转登录界面：

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8" import="java.sql.*"%>
 3 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 4 <html>
 5 <head>
 6 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 7 <title>检测跳转中</title>
 8 </head>
 9 <body>
10 <%
11 String name = new String(request.getParameter("username").getBytes("ISO-8859-1"),"UTF-8");
12 String pw = request.getParameter("password"); 
13 
14 String str = "select * from USERS WHERE username = '" + name + "'";
15 String str1 = "insert into users values(xuhao.nextval,'" + name + "','" + pw +"')";
16 
17 try{
18     
19      //连接数据库
20      Connection conn = null;
21      Class.forName("oracle.jdbc.driver.OracleDriver");
22      String strURL = "jdbc:oracle:thin:@localhost:1521:SP";
23      conn = DriverManager.getConnection(strURL, "test", "123");
24      System.out.println("数据库连接成功");
25      Statement st = conn.createStatement();
26      ResultSet rs = st.executeQuery(str);
27      if(rs.next()){
28          if(name.equals(rs.getString(2))){
29              out.println("对不起，用户名已使用。");
30              out.println("<br>建议使用用户名：" + name +"99"); 
31              response.setHeader("refresh", "5;URL=zhuce.jsp");
32          }
33      }else{
34          int a = st.executeUpdate(str1);
35          if(a == 1){
36              out.println("恭喜你，注册成功");
37              session.setAttribute("username", name);
38              response.setHeader("refresh", "3;URL=denglu.jsp");
39          }
40      }
41      
42      rs.close();
43      st.close();
44      conn.close();
45 }catch(Exception e){
46     e.printStackTrace();
47 }
48 %>
49 <br><br>
50 

52 </body>
53 </html>

登录时，密码出错：5秒后重新登录

账号密码输入正确，进入主页面：

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 4 <html>
 5 <head>
 6 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 7 <title>主页面</title>
 8 </head>
 9 <body>
10 主页面
11 <%
12 Object obj = session.getAttribute("username");
13 if(obj != null){
14     String str = obj.toString();
15     out.println(str + "登陆成功");
16 }else{
17     out.println("登录超时，请重新登录"); 
18     response.setHeader("refresh", "5;URL=denglu.jsp");
19 }
20 %>
21 <br>
22 
23 <a href="yemian.jsp">退出账号</a>
24 
25 </body>
26 </html>

jsp登录页面 雏形

jsp登录页面雏形