<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
String username="";
String password="";
request.setCharacterEncoding("UTF-8");
username=request.getParameter("username");
password=request.getParameter("password");
//如果用户名和密码都等于admin，则登录成功；
if("admin".equals(username) && "admin".equals(password))
{
session.setAttribute("loginUser",username);
request.getRequestDispatcher("login_success.jsp").forward(request, response);
}else{
response.sendRedirect("login_failure.jsp");//如果登录名或密码错误，则登录失败；
}
%>
login.jsp页面的代码：
<%@ page language="java" import="java.util.*" contentType="text/html; charset=UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>imooc-login</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<div id="container">
<div class="logo">
<a href="dologin.jsp"><img src="assets/006.jpg" alt="" /></a>
</div>
<div id="box">
<form action="dologin.jsp" method="post">
<p class="main">
<label>用户名:</label>
<input name="username" value="" />
<label>密码：</label>
<input type="password" name="passsword" />
</p>
<p class="space">
<input type="submit" value="登录" class="login" style=""/>
</p>
</form>
</div>
</div>
</body>
</html>
login_success.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<div id="container">
<div class="logo">
<a href="dologin.jsp"><img src="assets/006.jpg" alt="" /></a>
</div>
<div id="box">
<%
String loginUser="";
if(session.getAttribute("loginUser")!=null){
loginUser = session.getAttribute("loginUser").toString();
}
%>
欢迎您<font color="red"><%=loginUser%></font>，登陆成功！
</div>
</div>
</body>
</html>
login_failure.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<div id="container">
<div class="logo">
<img src="assets/006.jpg" alt="" />
</div>
<div id="box">
登陆失败！请检查用户名或密码！<br/>
<a href="login.jsp">返回登录</a>
</div>
</div>
</body>
</html>
这些就是所有页面的代码了
你最好吧别的页面的代码，也发上来。