2022-5-12

package com.home;

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;
import java.text.SimpleDateFormat;
import java.util.Date;

@WebServlet(name = "CookieWork", urlPatterns = "/cookie01")
public class CookieWork extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //设置响应的消息体的数据格式以及编码
        resp.setContentType("text/html;charset=utf-8");
        //1.获取所有Cookie
        Cookie[] cookies = req.getCookies();
        boolean a = false;
        if (cookies != null && cookies.length > 0) {
            for (Cookie cookie : cookies) {
                String name = cookie.getName();
                if ("lastTime".equals(name)) {
                    a = true;
                    Date date = new Date();
                    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
                    String format = sdf.format(date);
                    cookie.setValue(format);
                    cookie.setMaxAge(60 * 60 * 24 * 30 * 12);
                    resp.addCookie(cookie);
                    String value = cookie.getValue();
                    resp.getWriter().write("欢迎回来,您上次访问时间为:" + value + "");
                    break;
                }
            }
        }
        if (cookies == null || cookies.length == 0 || a == false) {
            Date date = new Date();
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            String format = sdf.format(date);

            Cookie cookie = new Cookie("lastTime", format);
            cookie.setMaxAge(60 * 60 * 24 * 30 * 12);
            resp.addCookie(cookie);
            resp.getWriter().write("您好，欢迎您首次访问");
        }

    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doPost(req, resp);
    }
}