public static boolean isValidExpression(String cronExpression) {

        try {
            new CronExpression(cronExpression);
        } catch (ParseException pe) {
            return false;
        }

        return true;
    }
Indicates whether the specified cron expression can be parsed into a
valid cron expression

@param cronExpression the expression to evaluate
@return a boolean indicating whether the given expression is a valid cron
        expression
server/core/src/main/java/com/ke/schedule/server/core/common/CronExpression.java