private void validateUser(User user) throws Exception {
StringBuilder errorList = new StringBuilder();
if (user.getUsername() == null
|| user.getUsername().equals("")
|| user.getPassword() == null
|| user.getPassword().equals("")) {
errorList.append("Please, provide username and password");
errorList.append(System.getProperty("line.separator"));
} else if (userService.find(user.getUsername(), Encryptor.MD5(user.getPassword())) == null) {
errorList.append("Please, provide valid username and password");
errorList.append(System.getProperty("line.separator"));
}
if (errorList.length() > 0) {
throw new Exception(errorList.toString());
}
}