private int subscribeRdfFiles(final File folder) {
	int count = 0;
	for (final File fileEntry : folder.listFiles()) {
	    if (fileEntry.isDirectory()) {
		subscribeRdfFiles(fileEntry);
	    } else {
		String regex = "([^\\s]+(\\.(?i)(ttl|rdf|n3))$)";
		if (fileEntry.getName().matches(regex)) {
		    System.out.println(fileEntry.getName());

		    String content_type = mimetypes_map
			    .getContentType(fileEntry);

		    FileInputStream fis;
		    try {
			fis = new FileInputStream(fileEntry);
			String content = IOUtils.toString(fis, "UTF-8");
			PostMethod subscription = new PostMethod(url.toString()
				+ "/register");
			subscription.setRequestEntity(new StringRequestEntity(
				content, content_type, "UTF-8"));

			client.executeMethod(subscription);

			if (subscription.getStatusCode() == 201) {
			    LOGGER.info(subscription.getStatusCode() + " :"
				    + subscription.getStatusText() + " "
				    + subscription.getPath());
			    count++;
			} else
			    LOGGER.error(subscription.getStatusCode() + " :"
				    + subscription.getStatusText() + " "
				    + subscription.getPath());

			subscription.releaseConnection();

		    } catch (IOException e) {
			e.printStackTrace();
		    }

		}
	    }
	}
	return count;
    }