关于Cookie的一些小饼干

protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //解决中文乱码问题
        req.setCharacterEncoding("utf-8");
        resp.setCharacterEncoding("utf-8");
        resp.setContentType("text/html;charset=utf-8");

        PrintWriter out = resp.getWriter();
        javax.servlet.http.Cookie[] cookies = req.getCookies();//服务器端从客户端获取饼干

        //判断cookies是否存在
        if(cookies!=null){
            out.write("上次登录的时间为：");
            for(int i=0;i<cookies.length;i++){
                Cookie cookie=cookies[i];
                if(cookie.getName().equals("lasttime")){
                    long lasttime = Long.parseLong(cookie.getValue());
                    Date date = new Date(lasttime);
                    out.write(date.toLocaleString());
                }
            }
        }else {
            out.write("你好，这是您第一次登录本站");
        }

        //服务器端给客户端响应一个cookie
        Cookie cookie = new Cookie("lasttime", System.currentTimeMillis()+"");
        cookie.setMaxAge(24*60*60);//设置cookie的生命周期为一天
        resp.addCookie(cookie);
    }

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

    }
}

还有如果用Cookie传递中文数据的要编码解码：

Cookie cookie = new Cookie("name", URLEncoder.encode("撒旦","utf-8"));//编码
out.write(URLDecoder.decode(cookie.getValue(),"utf-8"));//解码