Question

So right now I have a fairly basic Executor service that I use to break my program into threads, like so:

ExecutorService threadPool = Executors.newFixedThreadPool(12);
for (int i = 0; i < objectArray.length; i++) {
    threadPool.submit(new ThreadHandler(objectArray[i], i));
          // The i is used elsewhere
}

I was wondering if there was a good way to detect / close “crashed” or “frozen” threads? I took a look at the documentation but it doesn’t really seem to fit in with how I’m using this at all…

Can someone help me with this? Thanks

Answer 1

threadPool.submit returns Future<T> Object. So using this future Object you can have handle on your task execution.
By using isCancelled() and isDone method you can check task has been canceled or done. Even more get() is blocking call which throws exception on interpret or cancel or in executionexception.

List<Future<?>> list = new ArrayList<Future<?>>();
for (int i = 0; i < objectArray.length; i++) {
    Future<?> task=threadPool.submit(new ThreadHandler(objectArray[i], i));
          // The i is used elsewhere
    list.add(task);
}
for(Future future : list){
   try{
       future.get();
   }catch(CancellationException cx){
   ...
   }catch(ExecutionException ex){
   ...
   }catch(InterruptedException ix){
   ...
   }

}