Java – Is it a good way to use java.util.concurrent.FutureTask


First of all, I must say that I am quite new to the API java.util.concurrent, so maybe what I am doing is completely wrong.

What do I want to do?

I have a Java application that basically runs 2 separate processing (called myFirstProcess, mySecondProcess), but these processing must be run at the same time.

So, I tried to do that:

public void startMyApplication() {
    ExecutorService executor = Executors.newFixedThreadPool(2);
    FutureTask<Object> futureOne = new FutureTask<Object>(myFirstProcess);
    FutureTask<Object> futureTwo = new FutureTask<Object>(mySecondProcess);
    while (!(futureOne.isDone() && futureTwo.isDone())) {
        try {
            // I wait until both processes are finished.
        } catch (InterruptedException e) {
    }"Processing finished");
    // Do some processing on results

myFirstProcess and mySecondProcess are classes that implements Callable<Object>, and where all their processing is made in the call() method.

It is working quite well but I am not sure that it is the correct way to do that.
Is a good way to do what I want? If not, can you give me some hints to enhance my code (and still keep it as simple as possible).

Best Solution

You'd be better off using the get() method.


Both of which wait for notification from the thread that it finished processing, this saves you the busy-wait-with-timer you are now using which is not efficient nor elegant.

As a bonus, you have the API get(long timeout, TimeUnit unit) which allows you to define a maximum time for the thread to sleep and wait for a response, and otherwise continues running.

See the Java API for more info.