Getting all classes in Android project

I am trying to find a way to get a list of all the classes I've made in my Android project, probably using the reflections library.

I've seen other threads on this in the past, but many are years old, and there are occasional comments saying that older methods no longer work based on Gradle upgrades and such.

Older thread here: Find all classes in a package in Android

So I am curious if there is a commonly-accepted or known, definitive approach for how this is done as of 2016.