java按天生成两位流水号

直接利用redis的incrBy即可。

    private String getNewTaskNo() {
        String today = DateTimeUtil.dateToStr(new Date(), "yyyyMMdd");
        Long newNo = redisUtil.incrBy(today, 1);
        redisUtil.expire(today, 3600 * 24);
        return today + "-" + newNo;
    }

如果要精确控制expire的time，则可以使用

        Calendar calendar = Calendar.getInstance();
        calendar.setTime(new Date());
        calendar.set(Calendar.HOUR_OF_DAY, 24);
        calendar.set(Calendar.MINUTE, 0);
        calendar.set(Calendar.SECOND, 0);
        int lockTime = (int) ((calendar.getTimeInMillis() - System.currentTimeMillis()) / 1000);

如果要前面填充一个0，则：

    private String getNewTaskNo() {
        String today = DateTimeUtil.dateToStr(new Date(), "yyyyMMdd");
        Long newNo = redisUtil.incrBy(today, 1);
        redisUtil.expire(today, 3600 * 24);
        if (newNo < 10) {
            return today + "-" + "0" + newNo;
        }
        return today + "-" + newNo;
    }