java随机打乱集合顺序

public static void main(String[] args) {
        List <Integer> intList = new ArrayList<Integer>();   //汉字随机放入的位子
        intList.add(1);
        intList.add(2);
        intList.add(3);
        intList.add(4);
        Collections.shuffle(intList);
        for (int i = 0; i < intList.size(); i++) {
            System.out.println(intList.get(i));
        }

        System.out.println("-----------------");

        Integer[] arr = new Integer[] {1, 2, 3, 4};
        List<Integer> list = Arrays.asList(arr);
        Collections.shuffle(list);
        for (int i = 0; i < list.size(); i++) {
            System.out.println(list.get(i));
        }
    }