[Use Case]: Autostart for Scheduled Asynchronous methods

[njr-11]

As a ...

• Application user/user of the configuration itself
• API user (application developer)
• SPI user (container or runtime developer)
• Specification implementer

I need to be able to ...

arrange for an Asynchronous method to be automatically submitted/scheduled upon application startup

Which enables me to ...

more conveniently code applications that have business logic that should run on a schedule

Additional information

This requirement was discussed in a topic titled "Defining Jakarta EE 12 Scope in Program Plan" on the jakarta.ee-community mailing list.

One way to achieve this might be with a boolean autoSchedule field,

 @Asynchronous(runAt = @Schedule(daysOfWeek = DayOfWeek.TUESDAY, hours = 1),
               autoSchedule = true)
 public void weeklyTask() {
     ...
 }

Alternatively, instead of a boolean, we could use a long value, being a delay (in milliseconds? seconds? which unit is best?) to automatically start after. The default of -1 would mean don't automatically schedule on application startup, keeping existing applications compatible.

 @Asynchronous(runAt = @Schedule(daysOfWeek = DayOfWeek.TUESDAY, hours = 1),
               scheduleAfter = 1000)
 public void weeklyTask() {
     ...
 }

If we wanted, we could also allow it for one-time Asynchronous methods without a Schedule, in which case the name would need to be something more general like autoSubmit or submitAfter instead of autoSchedule or scheduleAfter.

[hantsy]

As EJB and Spring do, make sure all @Scheduled based scheduled tasks are scanned at deployment time and started automatically as the application is deployed.

Developers can control more details of the scheduled task by programmatic APIs, auto or not, conditionally generate the schedule settings, etc.