第八周作业
1.登陆
输入用户名密码，判断用户名和密码相同，登陆成功，session中保存用户的用户名，进入主页main.jsp，主页有一个退出按钮，点击，回到登陆页login.jsp。要求：退出登录后，如果在浏览器直接输入主页main.jsp，访问不了，直接跳到登陆页。
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>login</title>
</head>
<body>
<form name="form" action="index.jsp" method="post">
用户名：<input type="text" name="uname"><br>
密码：<input type="password" name="upwd"><br>
<input type="submit" value="登录" >
</form>
</body>
</html>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>dologin</title>
</head>
<body>
<%
request.setCharacterEncoding("utf-8");
String uname=request.getParameter("uname");
String upwd=request.getParameter("upwd");
if(uname.equals(upwd)){
session.setAttribute("uname", uname);
request.getRequestDispatcher("me.jsp").forward(request,response);
}else{
request.getRequestDispatcher("MyJsp.jsp").forward(request,response);
}
%>
</body>
</html>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>main</title>
</head>
<body>
<h1>登陆成功！</h1>
<%
String uname = (String) session.getAttribute("uname");
if (uname == null)
response.sendRedirect("index.jsp");
%>
<form name="form1" action="me.jsp" method="post">
<input type="submit" value="退出登录">
</form>
</body>
</html>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<html>
<head>
<title>no</title>
</head>
<body>
<h1>登陆失败！！</h1>
<%response.setHeader("refresh", "5;url=index.jsp");%>
</body>
</html>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>logout</title>
</head>
<body>
<%
session.invalidate();
response.setHeader("refresh", "5;url=index.jsp");
%>
</body>
</html>
