gistfile1.java

	public <T extends Room> List<Integer> getBatchPlayerAmountOfRooms(List<T> rooms) {
		if (rooms == null || rooms.size() == 0)
			return new ArrayList<Integer>(0);

		Collection<String> uidList = FPUtils.map(rooms, new FPUtils.MapFunc<T, String>() {
			@Override
			public String map(T room) {
				return roomCacheKey(room);
			}
		});

		final Map<String, Integer> cacheAmountList = FPUtils.map2(uidList, new FPUtils.MapFunc<String, Integer>() {
			@Override
			public Integer map(String roomUid) {
				return getLocalRoomPlayerAmountCache().get(roomUid);
			}
		});

		Collection<String> needfetchUids = FPUtils.filterMap(cacheAmountList,
				new FPUtils.MapEntryFilterFunc<String, Integer>() {
					@Override
					public boolean filter(Entry<String, Integer> entry) {
						return entry.getValue() == null;
					}
				}).keySet();

		Map<RoomState, Integer> fetchResult = loadBatchPlayerAmountOfRooms(needfetchUids);
		FPUtils.foreach(fetchResult.entrySet(), new FPUtils.ForeachFunc<Entry<RoomState, Integer>>() {
			@Override
			public void visit(Entry<RoomState, Integer> entry) {
				cacheAmountList.put(entry.getKey().getRoomUid(), entry.getValue());
			}
		});

		return new ArrayList<Integer>(cacheAmountList.values());
	}

	protected Map<RoomState, Integer> loadBatchPlayerAmountOfRooms(Collection<String> roomUids) {
		Collection<RoomState> states = RoomState.loadBatch(roomUids, cacheClient, this);
		return FPUtils.map2(states, new FPUtils.MapFunc<RoomState, Integer>() {

			@Override
			public Integer map(RoomState obj) {
				return obj.getPlayerAmount();
			}

		});
	}