CODEWITHSUNDEEP
javaplayframeworkakkascheduler
rampurearun
rampurearun

Reputation: 41

How to run akka scheduler in Java Play Framework on a particular day of the week?

I have to create a scheduler which runs at a particular day of week. For example my scheduler should run on every Monday at 11:50 PM. Please help me through the task.

PS: I went through these links How to schedule task daily + onStart() in Play 2.0.4? suggests using a cronJob expression to calculate next execution time. Is there a way to do using akka by default i.e. without a cronJob expression?

Upvotes: 2

Views: 2003

Answers (2)

Sankalp Mathur
Sankalp Mathur

Reputation: 1

public void onStart(Application application) {
  try{
      Duration.create(timeToNextMonday(), TimeUnit.MILLISECONDS),
      Duration.create(7, TimeUnit.DAYS),
      new Runnable() {
          @Override
          public void run() {
              JPA.withTransaction(new F.Callback0() {
                  @Override
                  public void invoke() throws Throwable {
                      System.out.println("Printing time : " + new Date());
                  }
              });
          }
      },
      Akka.system().dispatcher());
  }
  catch (Throwable t){
      HashMap<String,String> params = new HashMap<>();
      Logger.error("{}:params:{}", "error while starting cron for Historical TW questions", params, t);
  }
  super.onStart(application);
}
//In minutes
private long timeToNextMonday(){
    Calendar now = Calendar.getInstance();

    while (now.get(Calendar.DAY_OF_WEEK) != Calendar.MONDAY) {
        now.add(Calendar.DATE, 1);
    }

    now.set(Calendar.HOUR,11);
    now.set(Calendar.AM_PM,Calendar.PM);
    now.set(Calendar.MINUTE,50);
    now.set(Calendar.SECOND,00);
    now.set(Calendar.MILLISECOND,00);

    return now.getTime().getTime() - Calendar.getInstance().getTime().getTime();
}

Upvotes: 0

Didac Montero
Didac Montero

Reputation: 2086

schedule(initialDelay: Duration, frequency: Duration, receiver: ActorRef, message: Any)

You just need to calculate the initialDelay on the scale (minutes, hours, days) that you want. In your case, you have to find out the time until the next Monday. That's not an issue related with Akka, just plain Java:

//In minutes
private long timeToNextMonday(){
    Calendar now = Calendar.getInstance();
    now.set(Calendar.HOUR, 23);
    now.set(Calendar.MINUTE, 50);
    int weekday = now.get(Calendar.DAY_OF_WEEK);
    System.out.println(now.getTime());
    if (weekday != Calendar.MONDAY){
        // calculate how much to add
        // the 2 is the difference between Saturday and Monday
        int days = (Calendar.SATURDAY - weekday + 2) % 7;
        now.add(Calendar.DAY_OF_YEAR, days);
    }
    Date date = now.getTime();
    return (now.getTime().getTime() - System.currentTimeMillis())/(1000*60);
}

And then the schedule call itself is pretty straightforward:

Akka.system().scheduler().schedule(
    Duration.create(timeToNextMonday, TimeUnit.MINUTES),
    Duration.create(7, TimeUnit.DAYS),
    actor, actorMessage,
    Akka.system().dispatcher(), null);

Upvotes: 2

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