Good question. Unfortunately, I still don't have a good answer for that (but I am working on it).
Facebook's killing off of offline_access is a *GOOD* thing. Their approach is quite a bit closer to what the OAuth 2 spec does with refresh tokens (essentially, using the access token as its own refresh token). But, I still don't have a good answer for you on the *best* way to do this.
Certainly one way to do it (albeit cumbersome) is to directly query the UserConnections table to get the access token and then use RestTemplate to directly do the refresh yourself...followed by updating the UserConnection table, if necessary. That will work...but it's certainly not the best way to do it.
I'm also not certain that I would refresh every day...what if the user hasn't used your application in several weeks? Then you're refreshing for no reason. I'd tend to refresh only on realization that the token you have is no good.
This is a good opportunity for discussion on the topic, though. My thinking is that this would be handled much the same way as refresh tokens, only with a Facebook twist. I'm always open to ideas on how to do this, though.
Spring Social Project Lead