效果图如下

从数据库中随意使用一个账号登录

登陆成功来到人中心

返回登录界面

实现代码如下

package com.test.controller;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 com.test.service.UserService;/** * Servlet implementation class LoginServlet */@WebServlet("/login_do")public class LoginServlet extends HttpServlet {    private static final long serialVersionUID = 1L;           protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        // TODO Auto-generated method stub        request.setCharacterEncoding("UTF-8");        String username=request.getParameter("username");        String password=request.getParameter("password");                Cookie cookieUsername=new Cookie("username", username);        Cookie cookiePassword=new Cookie("password", password);                UserService userService=new UserService();        boolean isSuccess=userService.login(username, password);                if(isSuccess) {            request.setAttribute("msg", "登陆成功");            cookieUsername.setMaxAge(60*60*24*30);            cookiePassword.setMaxAge(60*60*24*30);                        response.addCookie(cookieUsername);            response.addCookie(cookiePassword);                        request.getRequestDispatcher("personCenter.jsp").forward(request, response);;        }else {            request.setAttribute("msg", "用户名或密码错误");            request.getRequestDispatcher("login.jsp").forward(request, response);        }    }}

<%@ page language="java" contentType="text/html; charset=utf-8"    pageEncoding="utf-8"%>
    <%String username="";String password="";Cookie[] cookies=request.getCookies();if(cookies!=null&&cookies.length>0){    for(int i=0;i
    
     
登录
${requestScope.msg }
     
     
      用户名
      
      
      
密码