if (res == null || res < 0) {
throw new RuntimeException("Couldn't register new oauth user");
}
user = userDao.get(res);
user.setExternalUserType("oauth2." + serverId);
userDao.update(user, null);
} else { // just change password
// check user type before changing password, it must be match oauthServerId
if (!("oauth2." + serverId).equals(user.getExternalUserType())) {
log.error("User already registered!");
return;