利用Cookie实现免用户名登陆----尚硅谷Javaweb_利用cookie实现免登陆-优快云博客

本文链接：https://blog.youkuaiyun.com/qq_52934831/article/details/122276351

实现思路

在这里插入图片描述

代码

Login.jsp

<%--
  Created by IntelliJ IDEA.
  User: hp
  Date: 2022/1/2
  Time: 14:11
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
 <form action="http://localhost:8080/13_cookie_session/loginServlet" method="get">
     用户名:<input type="text" name="username" value="${cookie.username.value}"> <br>
     密码：<input type="password" name="password" ><br>
     <input type="submit" value="登录">

 </form>
</body>
</html>

LoginServlet

package com.zlh.servlet;

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

public class LoginServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String username = req.getParameter("username");
        String password = req.getParameter("password");
        //登录成功
        if ("Zlh2001".equals(username)&& "xiaozhang".equals(password)){
            Cookie cookie= new Cookie("username",username);
            //设置生存时常为7天
            cookie.setMaxAge(60*60*24*7);
            resp.addCookie(cookie);
            System.out.println("登录成功");
        }
        //登录 失败
        else {
            System.out.println("登录失败");
        }
    }
}