Rayze is simple maze game made with raycasting engine. This project also has level editor for this game. You can create levels and save them to .maps file and later load them into the game and play. Editor is made using Java Swing and MVC pattern.
If you want to know more about how raycasting works check out this page. Also check out this page to see how you can implement it in Java.
For know you'll need to clone whole repository and import it in e.g. Eclipse or InteliJ IDEA.
git clone https://github.com/boris-ns/Rayze.git