import java.util.Arrays; import java.util.List; import java.util.concurrent.ForkJoinPool; public class FunctionalCollectionsExample { public static void main(String[] args) { List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5); numbers.parallelStream() } } System.setProperty("java.util.concurrent.ForkJoinPool.common.parallelism", "4");