if (url == null) {
            return null;
        }

        final FessConfig fessConfig = getFessConfig();
        String enc = Constants.UTF_8;
        if (StringUtil.isBlank(fessConfig.getCrawlerDocumentFileNameEncoding())) {
            final UrlQueue<?> urlQueue = CrawlingParameterUtil.getUrlQueue();
            if (urlQueue != null) {
                final String parentUrl = urlQueue.getParentUrl();