I am currently using federated authentication via openid in appengine - using google, yahoo, myopenid as the providers
Had a question as to what I should be storing in my db to identify returning users. I am currently storing user.getNickname() - (for google and yahoo this returns the users email address).
User user = userService.getCurrentUser();
String username = user.getNickname();
I use this to store and retrieve user specific data.
Is this the right way to proceed? Is the getNickName() unique? I see that User also has a user.getUserId() method and a user.getEmailId() method.
should I be using user.getUserId() instead?