用户免登陆

用户免用户名登陆

1、servlet代码

package com.qbb.web;

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 java.io.IOException;

/**
 * @author QiuQiu&LL
 * @create 2021-01-12  17:46
 * @Description:
 */
@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String username = request.getParameter("username");
        String password = request.getParameter("password");

        if("Qbb".equalsIgnoreCase(username) && "123".equalsIgnoreCase(password)){
            // 登录成功，用户名保存到Cookie中
            Cookie cookie = new Cookie("username", username);
            cookie.setMaxAge(60*60);
            response.addCookie(cookie);
            response.getWriter().write("success!");
        }else {
            // 登录失败
            response.sendRedirect(request.getContextPath()+"/login.jsp");
        }
    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}

2、login.jsp页面代码

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>登录页面</title>
</head>
<body>
  <form action="http://localhost:8080/cookie_session/loginServlet" method="post">
    用户名：<input type="username" name="username" value="${cookie.username.value}"><br>
    密码：<input type="password" name="password" value=""><br>
    <input type="submit" value="登录">
  </form>
</body>
</html>