java8删除两个list中的重复元素

public static void main(String[] args) {
        List<Integer> months = Lists.newArrayList();
        months.add(1);
        months.add(2);
        months.add(3);
        months.add(4);
        List<Integer> dels = Lists.newArrayList();
        dels.add(1);
        dels.add(2);
        months = months.stream()
                .filter(m1 -> !dels.contains(m1))
                .collect(Collectors.toList());
        for (Integer month : months) {
            System.out.println(month);
        }
    }
输出：
3
4

Process finished with exit code 0