Java8并行流中自定义线程池操作示例

@Test
publicvoidgivenList_whenCallingParallelStream_shouldBeParallelStream(){
  List aList = newArrayList<>();
  Stream parallelStream = aList.parallelStream();
  assertTrue(parallelStream.isParallel());
}

@Testpublic void giveRangeOfLongs_whenSummedInParallel_shouldBeEqualToExpectedTotal() throws InterruptedException, ExecutionException { long firstNum = 1; long lastNum = 1_000_000; List aList = LongStream.rangeClosed(firstNum, lastNum).boxed()
   .collect(Collectors.toList());
  ForkJoinPool customThreadPool = new ForkJoinPool(4);
  long actualTotal = customThreadPool.submit(
   () -> aList.parallelStream().reduce(0L, Long::sum)).get();
  assertEquals((lastNum + firstNum) * lastNum / 2, actualTotal);
}