cookie在web应用中实现上次登录时间以及上次访问时间 小案例理解cookie

package org.cookie.demo;

import java.io.IOException;

import java.io.PrintWriter;

import java.util.Date;

import javax.servlet.ServletException;

import javax.servlet.http.Cookie;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

public class CookieServlet extends HttpServlet {

/**

* 主要是通过一个案列来了解cookie的一些特性 用cookie来记载用户上一次登录的时间

*/

public void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

// 设置编码

response.setCharacterEncoding("UTF-8");

response.setContentType("text/html;charset=utf-8");

PrintWriter out = response.getWriter();

out.print("您上次访问的时间是:");

// 首先是后去cookie，记录当前访问时间

Cookie[] cookies = request.getCookies();

for (int i = 0; cookies != null && i < cookies.length; i++) {

if (cookies[i].getName().equals("lastAccessTime")) {

Long longTime = Long.parseLong(cookies[i].getValue());// 得到用户cookie上一次访问的时间

Date date = new Date(longTime);

out.print(date.toLocaleString());

}

}

Cookie cookie=new Cookie("lastAccessTime", System.currentTimeMillis()+"");

cookie.setMaxAge(1*30*24*3600);//设置cookie存放时间为一个月，如果不写的话，cookie默认为浏览器进程

cookie.setPath("/servletproject");//设置cookie路径

response.addCookie(cookie);

}

public void doPost(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

doGet(request, response);

}

}