获取两个list的差集方法

public class ListUtils<T> {
    /**
     * 获取两个list的差集
     * @param totalList 总的List
     * @param containsList 要排除的list
     * @return totallist - containsList
     */
    public List<T> getTwoListDifference(List<T> totalList,List<T> containsList){
        HashMap<T, Boolean> map = new HashMap(0);
        for (int i = 0; i < containsList.size(); i++) {
            map.put(containsList.get(i), true);
        }
        containsList.clear();
        for (int i = 0; i < totalList.size(); i++) {
            if (!map.containsKey(totalList.get(i))) {
                containsList.add(totalList.get(i));
            }
        }
        return containsList;
    }
}