public static List<String> getRecentTriggerTime(String cron) {
        List<String> list = new ArrayList<String>();
        try {
            CronTriggerImpl cronTriggerImpl = new CronTriggerImpl();
            cronTriggerImpl.setCronExpression(cron);
            // 这个是重点，一行代码搞定
            List<Date> dates = TriggerUtils.computeFireTimes(cronTriggerImpl, null, 20);
            SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            for (Date date : dates) {
                list.add(dateFormat.format(date));
            }

        } catch (ParseException e) {
            e.printStackTrace();
        }
        return list;
    }