实现获取用户上一次访问时间的功能，当用户访问服务器，如果是非第一次访问的话，需要将上次访问服务器的时间给用户显示出来

web.xml

    
        login.html
    

    
        Login
        com.exercise.login.Login
    
    
        Login
        /Login
    

 核心代码 

package com.exercise.login;


import javax.servlet.ServletException;
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;

public class Login extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //设置字符编码方式
        request.setCharacterEncoding("UTF-8");
        response.setContentType("text/html;charset=utf-8");
        String lastAccessTime=null;
        cookie[]cookies=request.getcookies();
        // 遍历cookie数组，取出上次访问时间
        for(int i=0;cookies!=null&&i