public void getCommentByDishId() {
		int dish_id;
		try {
			dish_id = Integer.valueOf(request.getParameter("dish_id").trim());
		} catch (Exception e) {
			jsonObject.put("RC", RC.PARAMETER_ERROR);
			return;
		}
		String last_time = request.getParameter("last_time");

		List<UserComment> comments;
		try {
			if (last_time == null) {
				comments = new UserCommentDao().getByDishId(dish_id);
			} else {
				comments = new UserCommentDao().getByDishId(dish_id, last_time);
			}
		} catch (Exception e) {
			jsonObject.put("RC", RC.SQL_EXCEPTION);
			return;
		}

		if (comments == null) {
			jsonObject.put("OC", OC.FAILIED);
		} else {
			jsonObject.put("OC", OC.SUCCESS);
			jsonObject.put("comment_count", comments.size());
			jsonObject.put("comments", JSONArray.fromObject(comments));
		}
	}