2018-10-31

ForkJoinPool pool = new ForkJoinPool(30);
final long begin = System.currentTimeMillis();
try {
    pool.submit(() ->
            numbers.parallelStream().map(k -> 
                {try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }return k;
            }).collect(Collectors.toList())).get();
} catch (InterruptedException e) {
    e.printStackTrace();
} catch (ExecutionException e) {
    e.printStackTrace();
}