Spring Scheduled task does not start on application startup

java spring spring-scheduled
v1shnu picture v1shnu · Feb 15, 2017 · Viewed 21.1k times · Source

I have a @Scheduled task in my application which is setup using CRON and run every 4 hours. The problem I face is that the CRON job does not start immediately after application startup but it starts only 4 hours after the application startup.

I tried to use a @PostConstruct method inside the task to invoke it, but that results in an error due to an uninitialized Spring context.

Please tell me how I can make the Scheduled task run immediately on application deployment and then on every 4 hours after the deployment.

EDIT:
I would not use a @PostConstruct since my scheduled method depends on other Beans , which are not initialized when this PostConstruct method runs for some reason.

Answer

Tomas F. picture Tomas F. · Feb 15, 2017

By 0 */4 * * * you specify "At minute 0 past every 4th hour (0:00, 4:00, 8:00 etc.)", which is not at startup time and then every 4 hours as I think you want. You can specify initial delay and rate by:

@Scheduled(initialDelay=0, fixedRate=4*60*60*1000)

If you are worried about hard-coded values, you can still provide config value:

@Scheduled(initialDelay=0, fixedRateString = "${some.config.string}")

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