Competitor to Unity with Java

[rupy]

So I'm thinking about building this C++ engine, but I really don't like working in C++/C, so I'm thinking of having the core engine be C++ and then you script the game in Java very similar to Unity. Has anything like this been done before.

Also do you know if there are many other small open source game engines like this one out there:

http://www.gameplay3d.io