private void fetchImages(ArrayList<Image> imageList,
			ArrayList<Image> totalImageList, String prefixUrl, String type,
			String orientation) {
		ArrayList<OSSObjectSummary> objectList = new ArrayList<OSSObjectSummary>();
		ObjectListing objectListing = null;
		String nextMarker = null;
		boolean fetchNextFlag = true;
		while (fetchNextFlag) {
			try {
				objectListing = ossClient.listObjects(new ListObjectsRequest(
						BUCKET_NAME, prefixUrl + "big/", nextMarker, "/",
						MAXNUM_PER_FETCH));
				objectList.addAll(objectListing.getObjectSummaries());
				nextMarker = objectListing.getNextMarker();
				if (nextMarker == null) {
					fetchNextFlag = false;
				} else {
					fetchNextFlag = true;
				}
				logger.info("next marker:" + nextMarker);
			} catch (Exception e) {
				logger.error("getMusic objectListing throws exception.");
				e.printStackTrace();
			}
		}
		for (int i = 1; i < objectList.size(); i++) {
			OSSObjectSummary ossObjectSummary = objectList.get(i);
			String key = ossObjectSummary.getKey();
			String name = key.substring((prefixUrl + "big/").length());
			String size = String.valueOf(ossObjectSummary.getSize());
			Image image = new Image(name, HOST_PREFIX + prefixUrl + "small/"
					+ name, HOST_PREFIX + prefixUrl + "big/" + name, type,
					orientation, size);
			RandomInsert(imageList, image);
			RandomInsert(totalImageList, image);
		}
	}