Java：使用Cookie记录客户端浏览器上次访问时间

浅浅的花香味﹌ 2022-12-25 12:55 132阅读 0赞

package cn.gpxxg.web.servlet;
    
    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.UnsupportedEncodingException;
    import java.net.URLDecoder;
    import java.net.URLEncoder;
    import java.text.DateFormat;
    import java.text.SimpleDateFormat;
    import java.util.Date;
    
    @WebServlet("/servletCookieDemo03")
    public class ServletCookieDemo03 extends HttpServlet {
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            request.setCharacterEncoding("utf-8");
    
            // 1、设置返回的格式
            response.setContentType("text/html;charset=utf-8");
    
            boolean flag = false;
            Cookie[] cookies = request.getCookies();
            for (Cookie cookie : cookies) {
                String name = cookie.getName();
                if ("lastTime".equals(name))
                {
                    // 找到了lastTime的cookie，获取值
                    flag = true;
                    String value = cookie.getValue();
                    System.out.println("解码前：" + value);
                    value = URLDecoder.decode(value, "utf-8");
                    System.out.println("解码后：" + value);
    
                    // 设置新的cookie,记录最新的时间
                    setLastTime(response, cookie);
    
                    // 输出到页面上
                    response.getWriter().write("<h1>欢迎回来，您上次的时间为" + value + "<h1>");
                    break;
                }
            }
    
            if (flag == false)
            {
                // 如果是一次来，提示欢迎新客户来，希望有一个好的购物体验
    
                // 1、设置返回的格式
                response.setContentType("text/html;charset=utf-8");
    
                // 2、记录当前时间到cookie，发送到客户端浏览器
                this.setLastTime(response, null);
    
                // 3、返回内容
                response.getWriter().write("<h1>欢迎新客户来，希望有一个好的购物体验</h1>");
            }
    
        }
    
        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            this.doPost(request, response);
        }
    
        public void setLastTime(HttpServletResponse response, Cookie cookie1) throws UnsupportedEncodingException {
    
            // 如果是lastTime的cookie,删除掉重新赋值
            if (cookie1 != null && "lastTime".equals(cookie1.getName()))
                cookie1.setMaxAge(0);
    
            // 时间格式
            Date date = new Date();
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月dd日 HH时mm分ss秒");
            String format = sdf.format(date);
            System.out.println("编码前：" + format);
            format = URLEncoder.encode(format, "utf-8");
            System.out.println("编码后：" + format);
    
            // 设置coolkie为当前时间
            Cookie cookie = new Cookie("lastTime", format);
            System.out.println(cookie);
    
            // 设置cookie的有效时间为1天
            cookie.setMaxAge(86400);
    
            response.addCookie(cookie);
    
        }
    }