Why do people immediately ask this kind of question when one mentions using vim or emacs for Java? I haven't found it to be any different than python or JS.
Because java codebases tend to be larger and programmers relie more on IDE features.
With Emacs and JDE it is nice.
Although Android Studio has been decent enough so I use Emacs less for Android development at the moment.
Just use a fuzzy finder a lot and it's pretty easy.