Hi @alpax and thanks for your query. Could you kindly clarify which Tobii hardware and platform you are working with?
Assuming that you are using one of the Tobii Consumer range of eye trackers (EyeX/4C) then I am afraid at this time we do produce Java specific bindings as the Tobii Core SDK targets the .NET platform.
That being said, a number of other users have tried to bridge the Tobii Stream Engine with Java and have shared their efforts online for which you can find one such project @ https://github.com/coylz/TobiiStreamEngineForJava
These projects are not supported by Tobii but may serve your needs. Please try them out and kindly let us know how you get on!