@Override
	public User loadUser(String userId) {
		User user = userService.getOne(userId);
		if (user != null) {
			user.setAuthProviderClass(this.getClass().getName());
		}
		return user;
	}
The default login plugin.

This retrieves the user
ngrinder-controller/src/main/java/org/ngrinder/security/DefaultLoginPlugin.java