判断是否是有效的cron表达式

    public static boolean isValidExpression(final String cronExpression){        CronTriggerImpl trigger = new CronTriggerImpl();        try {            trigger.setCronExpression(cronExpression);            Date date = trigger.computeFirstFireTime(null);            return date != null && date.after(new Date());        } catch (Exception e) {            LOGGER.error("[TaskUtils.isValidExpression]:failed. throw ex:" , e);        }        return false;    }