java List去重，并且保持顺序

 	List<T> list = new ArrayList<>();
	Set set = new HashSet();
    List<T> newList = new ArrayList<>();
    for (T element : list) {
        //set能添加进去就代表不是重复的元素
        if (set.add(element.getId())) newList.add(element);
    }
    list.clear();
    list.addAll(newList);
    //list就去重了