A simple example which shows how to work around the common Fork Join Pool in Java 8

gistfile1.java

public class ForkJoinTaskPoolTest {

    public static void main(String args[]) throws Exception {
        ThreadTest test = new ThreadTest();
        test.executeTasks();
    }

    void executeTasks() throws Exception {
        final List<Integer> firstRange = buildIntRange();
        final List<Integer> secondRange = buildIntRange();

        ForkJoinPool forkJoinPool = new ForkJoinPool(4);
        forkJoinPool.submit(() -> {
            firstRange.parallelStream().forEach((number) -> {
                try {
                    Thread.sleep(5);
                } catch (InterruptedException e) { }
            });
        });

        ForkJoinPool forkJoinPool2 = new ForkJoinPool(4);
        forkJoinPool2.submit(() -> {
            secondRange.parallelStream().forEach((number) -> {
                try {
                    Thread.sleep(5);
                } catch (InterruptedException e) {
                }
            });
        });

        Thread.sleep(20_000);
    }


    private List<Integer> buildIntRange() {
        List<Integer> numbers = new ArrayList<>(5);
        for (int i=0; i<60_000; i++)
            numbers.add(i);
        return Collections.unmodifiableList(numbers);
    }
}

main method should be ForkJoinTaskPoolTest test = new ForkJoinTaskPoolTest();