问题
My application loads some cron patterns from a properties file. Im 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 wich 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?
回答1:
Per the Javadocs, as of Spring 5.1.0 the @Scheduled annotation can accept "-" as the cron expression to disable the cron trigger.
The special value "-" indicates a disabled cron trigger, primarily meant for externally specified values resolved by a ${...} placeholder.
回答2:
If it was a cron expression, you could have used below which makes the cron run on 2099
59 59 23 31 12 ? 2099
But spring scheduler does not take a year as input. This is what I have found to defer it for some extended period. Below will run on 29 Feb which will be a leap year.
0 0 0 29 2 ?
回答3:
If you're stuck pre Spring 5.1.0 (SpringBoot < 2.1), your only option may be to disable the bean/service with the @Scheduled method altogether, for example by using a @ConditionalOnProperty("my.scheduleproperty.active") annotation and not setting the property (or setting it to false)
来源：https://stackoverflow.com/questions/36403671/spring-cron-scheduler-disable-pattern