Possible to change ejb parameter at runtime for @Schedule annotation?

Question

Probably a silly question for someone with ejb experience...

I want to read and change the minute parameter dynamically for one of my EJB beans that uses the Java EE scheduler via the @Schedule annotation. Anyone know how to do this at runtime as opposed to hardcoding it in the class like below? If i were to do it programatically could i still use the @Schedule annotation?

 @Schedule(dayOfWeek = "0-5", hour = "0/2", minute = "0/20", timezone = "America/Los_Angeles")
 private void checkInventory() {
 }

Answer 1

@Schedule is for automatic timers created by the container during deployment.

On the other hand, you can use TimerService which allows you to define at runtime when the @Timeout method should be called.

This might be interesting material for your: The Java EE 6 Tutorial - Using the Timer Service.

EDIT: Just to make this answer more complete. If it's a matter of is it possible than the answer would be - yes, it is.

There is a way to "change the parameters" of automatic timer created with @Schedule. Nevertheless it's quite extraordinary - it cancels the automatic timer and creates a similar programmatic one:

// Automatic timer - run every 5 seconds
// It's a automatic (@Schedule) and programmatic (@Timeout) timer timeout method
// at the same time (which is UNUSUAL)
@Schedule(hour = "*", minute = "*", second = "*/5")
@Timeout
public void myScheduler(Timer timer) {

    // This might be checked basing on i.e. timer.getInfo().
    firstSchedule = ...

    if (!firstSchedule) {
        // ordinary code for the scheduler
    } else {

        // Get actual schedule expression.
        // It's the first invocation, so it's equal to the one in @Schedule(...)
        ScheduleExpression expr = timer.getSchedule();

        // Your new expression from now on
        expr.second("*/7");

        // timers is TimerService object injected using @Resource TimerService.

        // Create new timer based on modified expression.
        timers.createCalendarTimer(expr);

        // Cancel the timer created with @Schedule annotation.
        timer.cancel();
    }
}

Once again - personally, I would never use such code and would never want to see anything like this in a real project :-) Either the timer is:

• automatic and is created by @Schedule by hard-coding the values or by defining them in ejb-jar.xml,
• programmatic and is created by the application code which can have different values in the runtime.