The Best Way To Learn Java ...With Robots 📎
Robocode is an integrated IRDE (Integrated Robot Development Environment) :-) initially created by IBM. It is easy to install and use. You can develop, compile and deploy your robot without leaving the IRDE. You will have to extend from a Robot class, react to (scan-, hit-) events etc. and learn Java with lots of fun.
If you already know Java - don't use it - it's addictive.