The Java EE 5 Tutorial (PDF) - Oracle Software Downloads

Using theTimer Service
2. Enter the admin username and password to log in to the Admin Console.
3. Click Web Services in the left pane of the Admin Console.
4. Click helloservice.
5. Click Test.
6. Under Methods, enter a name as the parameter to the sayHello method.
7. Click the sayHello button.
This will take you to the sayHello Method invocation page.
8. Under Method returned, you’ll see the response from the endpoint.
Using theTimer Service
666
Applications that model business work flows often rely on timed notifications. The timer
service of the enterprise bean container enables you to schedule timed notifications for all types
of enterprise beans except for stateful session beans. You can schedule a timed notification to
occur at a specific time, after a duration of time, or at timed intervals. For example, you could set
timers to go off at 10:30 AM on May 23, in 30 days, or every 12 hours.
When a timer expires (goes off), the container calls the method annotated @Timeout in the
bean’s implementation class. The @Timeout method contains the business logic that handles the
timed event.
The Timeout Method
Methods annotated @Timeout in the enterprise bean class must return void and take a
javax.ejb.Timer object as the only parameter. They may not throw application exceptions.
@Timeout
public void timeout(Timer timer) {
System.out.println("TimerBean: timeout occurred");
}
CreatingTimers
To create a timer, the bean invokes one of the createTimer methods of the TimerService
interface. (For details on the method signatures, see the javax.ejb.TimerService API
documentation.) When the bean invokes createTimer, the timer service begins to count down
the timer duration.
The bean described in “The timersession Example” on page 668 creates a timer as follows:
The Java EE 5Tutorial • June 2010