CompletableFASync.java

class CompletableFASync {

    private static CompletableFuture<Integer> doubleMe(final Integer number) {
        return CompletableFuture.completedFuture(number * 2);
    }

    public static void main(String[] args) throws InterruptedException {

        // Just an example future that returns double of an integer and convert it to String.
        final CompletionStage<String> processedCompletableFuture =
                doubleMe(20).thenApply(Object::toString);

        System.out.println("Main thread name = " + Thread.currentThread());
        //Just to make sure that we don't end
        Thread.sleep(3000);
    }
}