My application loads some cron patterns from a properties file. I'm using the @Scheduled annotation like this:
@Scheduled(cron = "${config.cronExpression:0 0 11,23 * * *}")
Now I want to disable some tasks and the easiest solution would be to enter a cron pattern which will never run. In order to do this, I thought about using a cron expression that only executes at a specific day in the past. But unfortunately the Spring cron expressions don't allow to add a year or a date in the past.
Is there any pattern that will never run?
As of Spring 5.1.0 the @Scheduled annotation can accept "-" as the cron expression to disable the cron trigger.
Per the Javadocs:
The special value
"-"indicates a disabled cron trigger, primarily meant for externally specified values resolved by a${...}placeholder.
Care must be taken if this value is used within a properties YAML file, as the hyphen has a special syntactical meaning in YAML of denoting a list entry. An easy solution is to put quotes around it so that it's interpreted as a literal string instead of a list entry:
cron-expression: "-"