@Schedule annotation run every few minutes (or seconds)

Question

I would like to try to use the @Schedule annotation in the following way:

public class MyTestServlet extends HttpServlet {
    private static JcanLogger LOG = JcanLoggerFactory.getLogger(ServiceTestServlet.class);

    @EJB CronService cronService;

    public void service(HttpServletRequest req, HttpServletResponse resp) throws .... {
    ....
    cronService.iLive(); 
}
---
    @Local // because the ejb is in a servlet (there is no other jvm)
public interface CronService {

    public void iLive();
    public void runsEveryMinute();
}
---
@Singleton
public class CronServiceBean implements CronService {
    private static final JcanLogger LOG = JcanLoggerFactory.getLogger(CronServiceBean.class);

    @Schedule(minute="*")
    public void runsEveryMinute() {
        LOG.info(" runs EveryMinute ");
    }

    public void iLive() {
        LOG.info("iLive");

    }
 ---
 LOG
 ... 
 CronServiceBean:34  ] iLive

Based on the log, the CronService live and well, but the scheduled task 'runsEveryMinute' doesnt work.

How should it work using an EJB scheduled task?

Answer 1

As per the Javadoc for the @Schedule annotation, the default values are:

• * for all fields except hour, minute, and second; and
• 0 for hour, minute, and second, by default.

By specifying minute="*" and leaving hour at its default of 0, it requests that the timer run every minute after midnight for one hour (i.e., 00:00, 00:01, 00:02, ..., 00:59) and then not again until the next day. Instead, use:

@Schedule(hour="*", minute="*")

To run every few seconds (e.g., 10 seconds), you can use a cron-like syntax:

@Schedule(hour = "*", minute = "*", second = "*/10", persistent = false)

By default, the scheduler persists events. Setting persistent = false will prevent them from building up over time, if so desired.