Basically, my title asks everything 
The technical answer is NO, but that is because Unity doesn’t use Java. It does have a language called JavaScript (very different to Java) that is fully capable of doing an FPS - I’m guessing that is what you are referring to in which case the answer is YES.
So, what your telling me is, I can have a 100% fully functional online FPS with Unity, with no C# scripting at all? I need to know because I want to focus on 1 single language.
(Sorry if this is annoying, I just need certainty.) 