public User registerUser(User user) throws IOException {
   UUID filename = UUID.randomUUID();
   String filePath =
       System.getProperty("geofertas.images.dir").toString().concat(filename.toString());
   File newFile = new File(filePath);
   FileUtils.writeByteArrayToFile(newFile, user.getPicture());
   user.setPicturePath(filename.toString());
   Object outcome = userDAO.registerUser(user);
   if (outcome != null) {
     User outcomeUser = (User) outcome;
     File file = new File(filePath);
     outcomeUser.setPicture(FileUtils.readFileToByteArray(file));
     return user;
   }
   return null;
 }