Re: FutureTask.cancel() - can anyone explain the mechanism?

From:

Piotr Kobzda <pikob@gazeta.pl>

Newsgroups:

comp.lang.java.help

Date:

Thu, 17 Sep 2009 19:48:55 +0200

Message-ID:

<h8tsq8$j2u$1@inews.gazeta.pl>

The Dude wrote:

         public Integer call() {

            try {

                while(true) {
                    final String message = this.blockingQueue.take();
                    System.out.println(message);
                }
            }
            catch (Throwable t) {
                System.out.println("Throwable caught in call() " + t.getCause
().getMessage());

The problem seems to be here (also in your other exception handlers).
Instead of the above try:

System.out.println("Throwable caught in call() " + t);

             }
            finally {
                System.out.println("Entered call() finally block.");
            }

            return new Integer((int)0);
        }
    }

    public static void main(String[] args) {

        final ExecutorService executor = Executors.newSingleThreadExecutor
();

        final MyCallable myCallable = new MyCallable();

        final Future<?> myFuture = executor.submit(myCallable);

        myCallable.put("Go Southend United FC!");

        myFuture.cancel(true);

This may cause no execution of your callable at all. Some delay is
needed before cancel.

HTH,
piotr