本文实例讲述了纯JSP实现的简单登录的方法。分享给大家供大家参考，具体如下：
文件共有四个web.xml、login.jsp、logout.jsp、welcome.jsp四个文件
测试环境：Tomcat 6.0.x
假设项目名称是LoginSample，我的目录结构是这样的
...\webapps\LoginSample\WEB-INF\web.xml
...\webapps\LoginSample\login.jsp
...\webapps\LoginSample\logout.jsp
...\webapps\LoginSample\welcome.jsp
web.xml源码清单：
<web-app xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"
version="2.4">
<welcome-file-list>
<welcome-file>welcome.jsp</welcome-file>
</welcome-file-list>
</web-app>
login.jsp源码清单：
<%@ page contentType="text/html;charset=UTF-8" %>
<html>
<head>
<title>JSP简单登录实例</title>
</head>
<body>
<h2>请登录</h2>
<form method="POST" >
Login Name: <input type="text" name="Name"><br>
Login Password: <input type="text" name="Password" ><br>
<input type="submit" value="Send"><br>
<form>
<%
if (request.getParameter("Name") != null
&& request.getParameter("Password") != null) {
String Name = request.getParameter("Name");
String Password = request.getParameter("Password");
if (Name.equals("a") && Password.equals("a")) {
session.setAttribute("Login", "OK");
session.setAttribute("myCount", new Integer(1));
response.sendRedirect("welcome.jsp");
}
else {
%>
登录失败:用户名或密码不正确～
<%
}
}
%>
</body>
</html>
logout.jsp源码清单：
<%@ page contentType="text/html;charset=UTF-8" %>
<html>
<%
session.setAttribute("Login", "");
%>
<body>
<h2>你已经退出登录</h2>
</body>
</html>
welcome.jsp源码清单：
<%@ page contentType="text/html" pageEncoding="UTF-8" import="java.util.*"%>
<html>
<body>
<h2>欢迎页面(测试session)</h2>
<%
String Login = (String)session.getAttribute("Login");
int nCount=0;
if (Login != null && Login.equals("OK")) {
Integer myCount = (Integer)session.getAttribute("myCount");
if(myCount!=null)
{
nCount = myCount.intValue();
nCount = nCount + 1;
session.setAttribute("myCount",new Integer(nCount));
}
%>
登录成功,myCount=<%=nCount%></br>
<input type=button value="退出" onclick="javascript:location.href='logout.jsp'">
<%
}
else {
%>
<jsp:forward page="login.jsp"/>
<%
}
%>
</body>
</html>
希望本文所述对大家JSP程序设计有所帮助。