Schedule Task in java using Timer

Question

I have created timezone specific schedule task event using java. My code is bellow.

Timer timer = new Timer();
Calendar date = Calendar.getInstance(TimeZone.getTimeZone("Asia/Colombo"));
date.set(Calendar.HOUR_OF_DAY, 0);
date.set(Calendar.MINUTE, 0);
date.set(Calendar.SECOND, 0);
timer.schedule(new TimerTask() {
    public void run() {
        System.out.println("Runs everday morning 12.00 AM");
    }
 }, date.getTime(), 1000 * 60 * 60 * 24);

But the problem is when call to this method it runs this task soon. I need to run this job 12.00 in Asia/Colombo time zone every day. How to do that?

Answer 1

You're scheduling your first execution in the past (midnight of the current day), and therefore your task will be executed immediately.

According to the javadoc :

[...] if the scheduled first time is in the past, it is scheduled for immediate execution.

The easiest way to fix this, is by adding 1 day to your scheduled first execution time:

date.add(Calendar.DATE, 1);

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Additionally, you probably want to schedule the execution of this task as fixed rate instead of fixed delay . If you don't, your task will be executed a little bit later every day, depending on the actual time it takes to complete the task. Again, see the javadoc for details.