private byte[] buildDirectoryMarkup() {
        StringBuilder body = new StringBuilder();
        File directory = new File(baseDirectory + directoryPath);
        File[] listOfFiles = directory.listFiles();
        if (listOfFiles != null) {
            body.append("<!DOCTYPE HTML><html><body>");

            for(File file : listOfFiles) {
                if (file.isFile() || file.isDirectory()) {
                    String relativeFilePath = buildRelativePath(directory.toString(), file.toString());
                    body.append(buildATag(relativeFilePath));
                }
            }

            body.append("</body></html>");
        }
        return body.toString().getBytes();
    }