Question

I have many threads running, but I want to execute a particular thread (a TimerTask’s run() method) to run to its completion and I don’t want any interruption by any other threads.

I think synchronized(this) { } wont ensure its completion.

Please suggest me a correct way to do this.

Answer 1

You can catch InterruptedException and set interrupt status once your work is completed.

Noncancelable tasks

Some tasks simply refuse to be interrupted, making them noncancelable. However, even noncancelable tasks should attempt to preserve the interrupted status in case code higher up on the call stack wants to act on the interruption after the noncancelable task completes. Listing 6 shows a method that waits on a blocking queue until an item is available, regardless of whether it is interrupted. To be a good citizen, it restores the interrupted status in a finally block after it is finished, so as not to deprive callers of the interruption request. (It can’t restore the interrupted status earlier, as it would cause an infinite loop — BlockingQueue.take() could poll the interrupted status immediately on entry and throws InterruptedException if it finds the interrupted status set.)

public Task getNextTask(BlockingQueue<Task> queue) {
boolean interrupted = false;
try {
    while (true) {
        try {
            return queue.take();
        } catch (InterruptedException e) {
            interrupted = true;
            // fall through and retry
        }
    }
} finally {
    if (interrupted)
        Thread.currentThread().interrupt();
}
}