Java集合中对象排序问题, 根据对象中的某个属性排序(集合的相关操作)

1. 根据集合中对象的某个属性值, 排序

  List<RoomCartypeParamters> roomCartypeParamtersList = new ArrayList<>();
        //进行排序, 按照指定字段升序排列
        Collections.sort(roomCartypeParamtersList, new Comparator<RoomCartypeParamters>() {
            @Override
            public int compare(RoomCartypeParamters o1, RoomCartypeParamters o2) {
                return o1.getId().compareTo(o2.getId());
            }
        });
        return roomCartypeParamtersList;
    }

2. 附加知识

2.1 set集合转list集合的操作

Set<RoomCartypeParamters> roomCartypeParamtersSet = new HashSet<>();
//可通过new的方式, 将set集合转为arrayList集合
 List<RoomCartypeParamters> roomCartypeParamtersList = new ArrayList(roomCartypeParamtersSet);

2.2 将小集合放入大集合中

List<RoomCartypeParamters> roomCartypeParamtersListAll = new ArrayList<>();
List<RoomCartypeParamters> roomCartypeParamtersList = roomCartypeParamtersMapper.getCarParamtersDetail(roomCartypeParamters);
                roomCartypeParamtersListAll.addAll(roomCartypeParamtersList);