帮助网站实现提示客户端计算机上次访问网站的时间

package net.wen.cookie; 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.net.URLDecoder;import java.net.URLEncoder;import java.text.SimpleDateFormat;import java.util.Date; @WebServlet(name = "TimeCookieServlet", urlPatterns = "/timeCookie")public class TimeCookieServlet extends HttpServlet {    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {     }     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        response.setContentType("text/html;charset=utf-8");         //制作当前时间字符串        SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月dd号，hh时mm分ss秒");        String curdata = sdf.format(new Date());        //因为我们即将传给cookie的值不能含有中文，所以进行编码        curdata = URLEncoder.encode(curdata,"utf-8");         Cookie[] cookies = request.getCookies();        Cookie timeCookie = new Cookie("timeCookie", curdata);        if(cookies!=null)//如果不是第一次访问        {            for (Cookie cookie : cookies) {                if(cookie.getName().equals("timeCookie")){                    String value = cookie.getValue();                    //解码                    value = URLDecoder.decode(value,"utf-8");                    response.getWriter().write("上次访问时间："+value);                    break;                }            }        }        if(cookies==null){//第一次访问            response.getWriter().write("第一次访问");        }        timeCookie.setMaxAge(9999);        response.addCookie(timeCookie);    }}