Open a file at @Timeout of a timerservice

Question

Every time I try to open a file at the @Timeout, Java returns Null Pointer Exception

@Singleton
public class EngineTrans {


@Resource
private TimerService timerService;

public void createProgrammaticalTimer() {

    ScheduleExpression everyTenSeconds = new     ScheduleExpression().second("*/15").minute("*").hour("4-20");
    timerService.createCalendarTimer(everyTenSeconds, new TimerConfig(
            "passed message " + new Date(), false));


}
@Timeout
public void handleTimer() {
    System.out.println("timer received - contained message is: " + new Date());

    File xmlFile = new   File(FacesContext.getCurrentInstance().getExternalContext().getRealPath(""));
}
}

Any ideas?

Answer 1

There is no JSF context within an @Timeout method. Perform the getRealPath call in the createProgrammaticalTimer method, and then pass it to the @Timeout method via the first parameter of the TimerConfig constructor (the "info" parameter). If necessary, create an inner class to hold all the data you need to pass to the @Timeout method:

@Singleton
public class EngineTrans {
  @Resource
  private TimerService timerService;

  private static class TimeoutData {
    private final Date date = new Date();
    private final String resourcePath;
    ...
  }

  public void createProgrammaticalTimer() {
    ...
    String resourcePath = FacesContext.getCurrentInstance().getExternalContext().getRealPath("...");
    TimeoutData timeoutData = new TimeoutData(resourcePath);
    timerService.createCalendarTimer(everyTenSeconds, new TimerConfig(timeoutData, false));
  }

  @Timeout
  public void handleTimer(Timer timer) {
    TimeoutData timeoutData = (TimeoutData)timer.getInfo();
    ...
  }
}