Map> RoomImagesMap = Maps.newHashMap();
RoomImagesMap.put(imageInfo.getRefId(), Lists.newArrayList());
RoomImagesMap.get(imageModel.getRefId()).add(imageModel);
Map> RoomImagesMap = Maps.newHashMap();
RoomImagesMap.put(imageInfo.getRefId(), Lists.newArrayList());
RoomImagesMap.get(imageModel.getRefId()).add(imageModel);
Map<Long, List<ImageModel>> RoomImagesMap = Maps.newHashMap();
定义了一个叫做RoomImagesMap,以Long为键,ImageModel的列表为值的Map
RoomImagesMap.put(imageInfo.getRefId(), Lists.<ImageModel>newArrayList());
将imageInfo的Refid作为键,而一个新的列表作为值插入这个Map
RoomImagesMap.get(imageModel.getRefId()).add(imageModel);
将mageModel插入刚才插入的,以Refid为键的那个Map条目的空白列表中