What is the best way to do Java development in Emacs?

What modes are the best?

And any tips or tricks that make developing java in emacs a bit better.

Is Emacs good for Java?

Emacs is a one-fits-all solution to programming and of course it also fits Java. That said, Java is a very special case. As you know, Java has very powerful reflection features and IDEs like Intellij or NetBeans use these to live with the language.

Is vim good for Java development?

Unfortunately, for most of that long time, Vim was not a viable option for Java (or Scala) development. But something has changed in the last year or two: the Language Server Protocol (LSP) has become really good. Honestly though, for most people, I still wouldn't recommend using Vim for Java development.

For anything else than casual Java editing, many people recommend the Java Development Environment for Emacs.