Retrieve all classes by package - Android [duplicate]

This question already has an answer here:

• Find all classes in a package in Android 7 answers

I'm wondering if there is a way to access all classes in a given package (by name) using Android (java).

I've tried using Reflections or accessing the dex files - but all my attempts failed probably due to the way gradle load the classes that is different from the way the JVM does.