并行流

并行流将任务分配给多个线程完成；

parallel

parallel方法将串行流转换为并行流；

public class Parallel_test {
    public static void main(String[] args) {
        Stream<Integer> stream = Stream.of(1,2,3,4,5,6,7,8,9);
        Integer sum = stream.parallel().peek(new Consumer<Integer>(){
                    @Override
                    public void accept(Integer num) {
                        System.out.println(num+Thread.currentThread().getName());
                    }
                }).filter(num->num>5)
                .reduce((result,ele)->result+ele)
                .get();
        System.out.println(sum);
    }
}

输出：

6main 3ForkJoinPool.commonPool-worker-9 5main 4ForkJoinPool.commonPool-worker-9 1main 7ForkJoinPool.commonPool-worker-4 9ForkJoinPool.commonPool-worker-13 8ForkJoinPool.commonPool-worker-2 2ForkJoinPool.commonPool-worker-11 30

parallelStream

获取并行流对象；

List<Author> authors = getAuthors();
authors.parallelStream()
        .map(author -> author.getAge())
        .map(age -> age + 10)
        .filter(age->age>18)
        .map(age->age+2)
        .forEach(System.out::println);