Stream() 切分List

SplitList.java

private static final Integer MAX_NUMBER = 3;
    public static void main(String[] args) {
        List<Integer> list = Arrays.asList(1, 2, 3, 4, 5, 6, 7);
        int limit = countStep(list.size());
        //方法一：使用流遍历操作
        List<List<Integer>> mglist = new ArrayList<>();
        Stream.iterate(0, n -> n + 1)
                .limit(limit)
                .forEach(i -> mglist.add(list
                        .stream()
                        .skip(i * MAX_NUMBER)
                        .limit(MAX_NUMBER)
                        .collect(Collectors.toList())));

        System.out.println(mglist);

        //方法二：获取分割后的集合
        List<List<Integer>> splitList = Stream.iterate(0, n -> n + 1)
                .limit(limit)
                .parallel()
                .map(a -> list
                        .stream()
                        .skip(a * MAX_NUMBER)
                        .limit(MAX_NUMBER)
                        .parallel()
                        .collect(Collectors.toList()))
                .collect(Collectors.toList());
        System.out.println(splitList);
    }

    /**
     * 计算切分次数
     */
    private static Integer countStep(Integer size) {
        return (size + MAX_NUMBER - 1) / MAX_NUMBER;
    }