Timer Schedule TimerTask for same hour every day

[Tomer]

If the current time is 18:50 and i schedule Repeating daily TimerTask
to 18:52 then everything is file its being run at 18:52 daily however
if i schedule it to 18:48 then its being run immediately (and i dont
want that) as i run the application
However i wanted it to be run every day at 18:48! how can i achieve
that?

following is my test code:

public class TestTimer {

public static class TestTimerTask extends TimerTask {

public void run() {
System.out.println(new Date() + " timer run...");
}
}

public static void main(String[] args) throws Exception {
Timer timer = new Timer();
Calendar date = Calendar.getInstance();
// Timer starts yesterday (so that surely will run today when time
comes.
// date.setTimeInMillis(new Date().getTime() - 1000 * 60 * 60 * 24);
DateFormat sdf = new SimpleDateFormat("HH:mm");
Date dateToBackup = null;
try {
dateToBackup = sdf.parse("18:32");
} catch (ParseException e) {
e.printStackTrace();
}
Calendar calendar = Calendar.getInstance();
calendar.setTime(dateToBackup);
date.set(Calendar.HOUR, calendar.get(Calendar.HOUR));
date.set(Calendar.MINUTE, calendar.get(Calendar.MINUTE));
date.set(Calendar.SECOND, calendar.get(Calendar.SECOND));
date.set(Calendar.MILLISECOND, 0);

// Schedule to run every day.
timer.schedule(
new TestTimerTask(),
date.getTime(),
1000 * 60 * 60 * 24
);
Thread.sleep(120000);
}

}

Thanks

Tomer

 

[Arne Vajhøj]

If the current time is 18:50 and i schedule Repeating daily TimerTask
to 18:52 then everything is file its being run at 18:52 daily however
if i schedule it to 18:48 then its being run immediately (and i dont
want that) as i run the application
However i wanted it to be run every day at 18:48! how can i achieve
that?

Timer timer = new Timer();
Calendar date = Calendar.getInstance();
// Timer starts yesterday (so that surely will run today when time
comes.
// date.setTimeInMillis(new Date().getTime() - 1000 * 60 * 60 * 24);
DateFormat sdf = new SimpleDateFormat("HH:mm");
Date dateToBackup = null;
try {
dateToBackup = sdf.parse("18:32");
} catch (ParseException e) {
e.printStackTrace();
}
Calendar calendar = Calendar.getInstance();
calendar.setTime(dateToBackup);
date.set(Calendar.HOUR, calendar.get(Calendar.HOUR));
date.set(Calendar.MINUTE, calendar.get(Calendar.MINUTE));
date.set(Calendar.SECOND, calendar.get(Calendar.SECOND));
date.set(Calendar.MILLISECOND, 0);

Why not just roll one day forward ?

// Schedule to run every day.
timer.schedule(
new TestTimerTask(),
date.getTime(),
1000 * 60 * 60 * 24
);
Thread.sleep(120000);
}

}

Arne

 

[ilkinulas]

if timer execution time is earlier then the current time then
roll one day forward.

public void scheduleTimer(int hour, int minute) {
Calendar now = new GregorianCalendar();
int hourNow = now.get(Calendar.HOUR_OF_DAY);
int minuteNow = now.get(Calendar.MINUTE);

Calendar firstExecutionDate = new GregorianCalendar();
firstExecutionDate.set(Calendar.HOUR_OF_DAY, hour);
firstExecutionDate.set(Calendar.MINUTE, minute);
firstExecutionDate.set(Calendar.SECOND, 0);
firstExecutionDate.set(Calendar.MILLISECOND, 0);
if (hour<hourNow || (hour==hourNow && minute<minuteNow)) {
//Do not execute today, first execution will be tomorrow.
firstExecutionDate.add(Calendar.DAY_OF_MONTH, 1);
}

long oneDay = 1000L * 60L * 60L * 24L;

Timer timer = new Timer();
timer.schedule(new MyTask(), firstExecutionDate.getTime(), oneDay);

}

 

[Roedy Green]

However i wanted it to be run every day at 18:48! how can i achieve
that?

I don't think that is a sensible way to handle the problem. You would
need an JVM sitting in RAM 24-7.

Better to use some light weight chron feature of the OS.

 

[Arne Vajhøj]

I don't think that is a sensible way to handle the problem. You would
need an JVM sitting in RAM 24-7.

Better to use some light weight chron feature of the OS.

cron

There is that little aspect called portability.

But if it is a server running 24 x 7 it should probably
use Java EE and scheduling has been part of Java EE since
version 1.4 !

Arne

 

[Tomer]

Why not just roll onedayforward ?





Arne

I didnt want to roll one day forward because i didnt want to have
special cases in my code like checking if the current time is later
than scheduled time and in that case roll one day forward, but now
that i see i have no choice, then i would need to check for that
special case and roll one day forward.

Thanks,

Tomer

 

[Arne Vajhøj]

I didnt want to roll one day forward because i didnt want to have
special cases in my code like checking if the current time is later
than scheduled time and in that case roll one day forward, but now
that i see i have no choice, then i would need to check for that
special case and roll one day forward.

I think your problem includes a condition, so it I don't think
you can avoid a condition in your code.

Arne