For some reason, Android file methods confused me, so I just decided to test all outputs and post it here

Android file methods output.txt

Environment.getExternalStorageDirectory()
 - /storage/emulated/0

Environment.getExternalStoragePublicDirectory("") // Error on `null`
 - /storage/emulated/0

Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES)
 - /storage/emulated/0/Pictures

getExternalFilesDir(null) // Parameter "" returns the same
 - /storage/emulated/0/Android/data/com.nowhere.testexternalstorage/files

getExternalFilesDir(Environment.DIRECTORY_PICTURES)
 - /storage/emulated/0/Android/data/com.nowhere.testexternalstorage/files/Pictures

getExternalFilesDirs(null) // Parameter "" returns the same
 - /storage/emulated/0/Android/data/com.nowhere.testexternalstorage/files
 - /storage/6363-3466/Android/data/com.nowhere.testexternalstorage/files

getExternalMediaDirs()
 - /storage/emulated/0/Android/media/com.nowhere.testexternalstorage
 - /storage/6363-3466/Android/media/com.nowhere.testexternalstorage
 
getExternalCacheDirs()
 - /storage/emulated/0/Android/data/com.nowhere.testexternalstorage/cache
 - /storage/6363-3466/Android/data/com.nowhere.testexternalstorage/cache
 
getDir("", 0)
 - /data/user/0/com.nowhere.testexternalstorage/app_

getDir("somename", 0)
 - /data/user/0/com.nowhere.testexternalstorage/app_somename
 
getFilesDir
 - /data/user/0/com.nowhere.testexternalstorage/files

getCacheDir
 - /data/user/0/com.nowhere.testexternalstorage/cache

getDataDir: Throws Error `java.lang.NoSuchMethodError: No virtual method getDataDir()Ljava/io/File; in class Lcom/nowhere/testexternalstorage/MainActivity; or its super classes (declaration of 'com.nowhere.testexternalstorage.MainActivity' appears in /data/app/com.nowhere.testexternalstorage-2/split_lib_slice_4_apk.apk)`

Wow. There is pattern.

getExternalBlahDir: /storage/emulated/0/Android/data/com.name.packname/Blah

getBlahDir: /data/user/0/com.name.packname/Blah

Environment.getExternalStorageBlah: /storage/emulated/0

Non-Environment class, that is, context methods return a path with com.name.packname in it.

So ... if you want a directory with your project name on it in the internal storage (in File explorer or Nautilus in Ubuntu), use Environment.getExternalStoragePublicDirectory("YOUR PROJECT NAME")?