jsp实现简单用户7天内免登录

%@ page language="java" contentType="text/html; charset=utf-8"
  pageEncoding="utf-8"%>
!DOCTYPE html>
html>
head>
meta charset="utf-8">
title>Insert title here/title>
/head>
body>
form action="LoginServlet" method="post">
  用户名：input type="text" name="username" value="${cookie.cook_name.value }"/>br/>
  input type="checkbox" name="chkCookie" value="7"/>记住我，7天内免登录br/>
  input type="submit" value="登录"/>br/>
  a href="sessionUser.jsp" rel="external nofollow" >验证session/a>
  a href="cookieUser.jsp" rel="external nofollow" >验证cookie/a>
/form>
/body>
/html>

%@ page language="java" contentType="text/html; charset=utf-8"
  pageEncoding="utf-8"%>
!DOCTYPE html>
html>
head>
meta charset="utf-8">
title>Insert title here/title>
/head>
body>
% 
   //从浏览器获取cookie
   Cookie[] cookies = request.getCookies();

   String uname = null;
   
   //判断语句条件小技巧
   if(null != cookies){
    for(Cookie cookie:cookies){
   //遍历本地浏览器中的所有cookie
   if(cookie.getName().equals("cook_name")){
    //把cookie中的用户名取出
    uname = cookie.getValue();
   }
   //out.print("p>name: " + cookie.getName()+"/p>");
   //out.print("p>value: " + cookie.getValue()+"/p>");
    
   }
    
    }
   //判断cookie有没有失效
   if(null != uname){
   out.print("p>用户名："+uname +"/p>");
   }
   else{
   response.sendRedirect("login.jsp");
   }
%>
/body>
/html>

package com.servlet;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 * Servlet implementation class LoginServlet
 */
@WebServlet("/LoginServlet")
public class LoginServlet extends HttpServlet {
 private static final long serialVersionUID = 1L;
    
  /**
   * @see HttpServlet#HttpServlet()
   */
  public LoginServlet() {
    super();
    // TODO Auto-generated constructor stub
  }

 /**
 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
 */
 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 // TODO Auto-generated method stub
 //获取用户登录名
 String username = request.getParameter("username");
 
 //获取7天内是否免登录
 String day7 = request.getParameter("chkCookie");
 int cookie_day = 1;
 if(null != day7  day7.equals("")){
  
  cookie_day = Integer.valueOf(day7);
 }
 
 //创建cookie
 Cookie cookie = new Cookie("cook_name",username);
 
 //设置Cookie有限期
 //cookie.setMaxAge(6);//有效期6秒
 cookie.setMaxAge(3600 * 24 * cookie_day);//设置7天免登录
 
 //写入cookie到浏览器
 response.addCookie(cookie);
 response.sendRedirect("cookieUser.jsp");
 
 
 }

 /**
 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
 */
 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 // TODO Auto-generated method stub
 doGet(request, response);
 }

}