Why is UncaughtExceptionHandler not called by ExecutorService?

Question

I\'ve stumbled upon a problem, that can be summarized as follows:

When I create the thread manually (i.e. by instantiating java.lang.Thread) the U

Answer 1

Quote from the book Java Concurrency in Practice(page 163),hope this helps

Somewhat confusingly, exceptions thrown from tasks make it to the uncaught exception handler only for tasks submitted with execute; for tasks submitted with submit, any thrown exception, checked or not, is considered to be part of the task’s return status. If a task submitted with submit terminates with an exception, it is rethrown by Future.get, wrapped in an ExecutionException.

Here is the example:

public class Main {

public static void main(String[] args){


    ThreadFactory factory = new ThreadFactory(){

        @Override
        public Thread newThread(Runnable r) {
            // TODO Auto-generated method stub
            final Thread thread =new Thread(r);

            thread.setUncaughtExceptionHandler( new Thread.UncaughtExceptionHandler() {

                @Override
                public void uncaughtException(Thread t, Throwable e) {
                    // TODO Auto-generated method stub
                    System.out.println("in exception handler");
                }
            });

            return thread;
        }

    };

    ExecutorService pool=Executors.newSingleThreadExecutor(factory);
    pool.execute(new testTask());

}



private static class TestTask implements Runnable {

    @Override
    public void run() {
        // TODO Auto-generated method stub
        throw new RuntimeException();
    }

}

I use execute to submit the task and the console outputs "in exception handler"