Java计算精准时间差

适用场景为某个活动倒计时或者定时器

            SimpleDateFormat f = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            Date date1 = new Date();
            Thread.sleep(1000);
            Date date2 = new Date();
            
            String createTime = f.format(date1);
            String nowTime = f.format(date2);
            int timeValue = 0;
            try {
          		//
                date1 = f.parse(createTime);
                date2 = f.parse(nowTime);
                //单位为毫秒
                long diff = date2.getTime() - date1.getTime();
                //时间差，精确到分钟
                long diffMinutes = diff / (60 * 1000);
                //精确到小时
                long diffMinutes = diff / (60 * 60 * 1000);
                //精确到天
                long diffMinutes = diff / (24 * 60 * 60 * 1000);
            } catch (Exception e) {
                e.printStackTrace();
            }