【Java】【cookie和session】Cookie

package com.stu.demo;

import jericho.tools.MyDatetime;

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.io.PrintWriter;

@WebServlet(name = "Demo")
public class Demo extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    request.setCharacterEncoding("utf-8");
    response.setCharacterEncoding("utf-8");
    PrintWriter out = response.getWriter();
    
    if (request.getParameter("type").equals("clear")) {
    //      清除cookie
        Cookie cookie = new Cookie("lastAccessTime","");
        cookie.setPath("/");
        cookie.setMaxAge(0); // 设置保存时间为0视为清除
        response.addCookie(cookie);
    }else{
        Cookie[] cookies = request.getCookies();
        for (int i = 0; i < cookies.length && cookies[i] != null; i++) {
            if (cookies[i].getName().equals("lastAccessTime")) {
                out.println("上次访问时间：" + new MyDatetime(cookies[i].getValue()).get());
            } else {
    //          记录访问时间
                out.println("第一次访问");
            }
        }
        Cookie cookie = new Cookie("lastAccessTime", System.currentTimeMillis() + "");
        cookie.setMaxAge(720 * 3600); // 设置保存时间则保存到硬盘上，不设置则保存到浏览器内存中
        cookie.setPath("/");
        response.addCookie(cookie);
    }
}

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