Cookie是小段的文本信息，在网络服务器上生成，并发送给浏览器，通过使用cookie可以标识用户身份，记录用户名和密码，跟踪重复等。
首先创建index.jsp：
<%@page import="java.net.URLDecoder"%>
<%@page import="javax.activation.URLDataSource"%>
<%@ 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>
<%
Cookie[] cookies=request.getCookies();
//从request中获得cookie对象的集合
String user="";
String date="";
if(cookies !=null){
//遍历cookie对象集合
for(int i=0;i<cookies.length;i++){
if(cookies[i].getName().equals("cdp")){
user=URLDecoder.decode(cookies[i].getValue().split("#")[0]);
//获取用户名
date=cookies[i].getValue().split("#")[1];
//获取注册时间
}
}
}
if("".equals(user)&&"".equals(date)){
//如果没有注册
%>
<p>
游客您好，欢迎初次光临！
</p>
<form action="MyJsp.jsp method="post"></form>
请输入姓名:<input name="user" type="text" value=""><br>
<input type="submit" value="确定">
<%
}else{
//已注册
%>
欢迎<b><%=user %>再次光临<br>
你注册的时间是:<%=date %>
<%
}
%>
</body>
</html>
再创建MyJsp.jsp，用于向cookie中写入对象注册信息：
<%@page import="java.net.URLEncoder"%>
<%@page import="java.net.URLDecoder"%>
<%@ 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 ‘MyJsp.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>
<%
request.setCharacterEncoding("GB18030");
//设置请求的编译为GB18030
String user=URLEncoder.encode(request.getParameter("user"),"utf-8");
//获取用户名
Cookie cookie=new Cookie("cdp",user+"#"+new java.util.Date().toLocaleString());
//创建并实例化Cookie对象
cookie.setMaxAge(60*60*24*30);
//设置Cookie有效时间为30天
response.addCookie(cookie);
//保存Cookie
%>
<script type="text/javascript">window.location.href="index.jsp"</script>
</body>
</html>
时间： 2024-08-05 11:17:56