Java 8 並列ストリームでカスタム スレッド プールを使用するにはどうすればよいですか?

// CPU-intensive tasks in separate threads leveraging parallel streams
ExecutorService es = Executors.newCachedThreadPool();

es.execute(() -> runTask(1000)); // Incorrect task
es.execute(() -> runTask(0));
es.execute(() -> runTask(0));
es.execute(() -> runTask(0));
es.execute(() -> runTask(0));
es.execute(() -> runTask(0));

final int parallelism = 4;
ForkJoinPool forkJoinPool = null;
try {
    forkJoinPool = new ForkJoinPool(parallelism);
    final List<Integer> primes = forkJoinPool.submit(() -> {
        // Parallel task here, for example:
        return IntStream.range(1, 1_000_000).parallel()
                .filter(PrimesPrint::isPrime)
                .boxed()
                .collect(Collectors.toList());
    }).get();
    System.out.println(primes);
} catch (Exception e) {
    throw new RuntimeException(e);
} finally {
    if (forkJoinPool != null) {
        forkJoinPool.shutdown();
    }
}