Java set a callback from ExecutorService

Question

I have a fixedThreadPool that I am using to run a bunch of worker threads to achieve parallel execution of a task with many components.

When all threads have finishe

Answer 1

So, I was wondering if it's possible to attach a callback function to the event of a thread finishing using the ExecutorService.

Not directly, no, but there are a couple of ways you could accomplish this. The easiest way that comes to mind is to wrap your Runnable in another Runnable that does the reaping of the results.

So you'd do something like:

threadPool.submit(new ResultPrinter(myRunnable));
...

private static class ResultPrinter implements Runnable {
    private final MyRunnable myRunnable;
    public ResultPrinter(MyRunnable myRunnable) {
        this.myRunnable = myRunnable;
    }
    public void run() {
        myRunnable.run();
        Results results = myRunnable.getResults();
        // print results;
    }
}