public static String getPostData(HttpServletRequest req) {

    StringBuilder sb = new StringBuilder();

    try {

        BufferedReader reader = req.getReader();

        reader.mark(10000);

        String line;

        do {

            line = reader.readLine();

            sb.append(line).append("\n");

        } while (line != null);

        reader.reset();

        // do NOT close the reader here, or you won't be able to get the post data twice

    } catch(IOException e) {

        logger.warn("getPostData couldn't.. get the post data", e);  // This has happened if the request's reader is closed

    }

    return sb.toString();

}