Yeah, some kind people over Reddit also shared some nice repositiories like this one: https://github.com/takari/polyglot-maven

Which would have been great if I found it earlier, since it allows you to use maven but write Java.

The only edge 1JPM has compared to that project is that auto-complete and even more advanced features of your IDE work with it, since you can also move your JPM.java file into ./src/main/java.