private List<Integer> compareWithHistory(String user_id
			, List<Map.Entry<Integer, Double> > recommendList) throws Exception {

		List<Integer> dishList = new ArrayList<Integer>();
		DishHistoryDao dishHistoryDao = new DishHistoryDao();

		List<?> list;
		for (Entry<Integer, Double> entry : recommendList) {
			list = dishHistoryDao.getByUserIdAndDishId(user_id, entry.getKey());
			if (list == null || list.isEmpty())
				dishList.add(entry.getKey());
		}
		if (dishList.size() >= 10)
			dishList = dishList.subList(0, 10);
		return dishList;
	}