in src/main/groovy/grails/plugins/quartz/config/TriggersConfigBuilder.groovy [198:211]
private prepareCronTriggerAttributes(Map triggerAttributes) {
prepareTriggerAttribute(
triggerAttributes,
Constants.CRON_EXPRESSION,
Constants.DEFAULT_CRON_EXPRESSION,
{
if (!CronExpression.isValidExpression(it.toString())) {
throw new IllegalArgumentException(
"Cron expression '${it}' in the job class ${jobName} is not a valid cron expression"
)
}
}
)
}