Java 8方法参数列表的并行流

Question

我有一个方法：

invokList(List<Object> list);

此方法在jar中，我无法访问它的源代码。因此，我需要以并行方式执行invokList，有人可以为此提供帮助吗？

想法是将列表拆分为多个列表，然后并行执行invokList。

我做了这个例子：

            import java.util.Arrays;
            import java.util.Collections;
            import java.util.List;

            public class Test {

                public static void main(String[] args) {
                    List<Integer> list = Arrays.asList(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20);
                    list.parallelStream()
                            .map(Collections::singletonList)
                            .forEach(Test::invokList);
                }

                public static void invokList(List<Integer> list) {
                    try {
                        Thread.sleep(100);
                        System.out.println("The Thread :" + Thread.currentThread().getName() + " is processing this list" + list);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }

Answer 1

Guava has methods Lists.partition and Iterables.partition that do something like what you're asking. Say you have a large List and want to process it in chunks of 5, you could do:

int batchSize = 5;
Lists.partition(list, batchSize)
   .parallelStream()
   .forEach(batch -> invokeList(batch));