Android list1去除list2中的元素

public static void main(String[] args) {
        List<String> firList = new ArrayList<String>();
        firList.add("1");
        List<String> twoList = new ArrayList<String>();
        twoList.add("2");
        twoList.add("3");
        firList.removeAll(twoList);
        System.out.println(firList.toString());
    }