I see that RestFB has added access to Reactions in the Post, Photo and Video objects, but it does not seem to have access from a Url. What would be the best way to get the Reactions on a Url? Do I need to call the Graph API directly?
RestFB does not support reactions on open graph objects. So you should call the opengraph id as you mentioned in the comment above and work with the
fetchConnection call. As Type you should use
Connection<Reactions.ReactionItem> con = client.fetchConnection("<ogid>/reactions", Reactions.ReactionItem.class);
I think this should work. The code is untested ;)