class JobSchedulerConfiguration extends AbstractConfiguration {

    void validateCron() {
        if (this.cronExpression == null) {
            this.throwExceptionAndLogError("cronExpression must not be null for CRON Scheduler");
        } else if (!CronExpression.isValidExpression(this.cronExpression)) {
            this.throwExceptionAndLogError("cronExpression : " + this.cronExpression + " is not valid");
        }
        if (this.initialDelay != null) {
            this.throwExceptionAndLogError("initialDelay must not be set for CRON Scheduler");
        }
        if (this.fixedDelay != null) {
            this.throwExceptionAndLogError("fixedDelay must not be set for CRON Scheduler");
        }
    }

}