Microblogging engine in Java

Question

Is anybody aware of any open source Twitter/Identica-like microblogging engines written in Java? My basic requirements are that users should be able to

1. Write short comments on some entities in the web application
2. Customize privacy features, like "do not show name/email"
3. Like/dislike comments

and optionally, track user locations.

The ones I've found so far were written in ASP.net (Yonkly), PHP (StatusNet, Floopo, Jisko) or Python (Jaiku).

Answer 1

You could start with the Atmosphere Framework with its JQuery plugin to implement Comet techniques.