Refactor, remove use of commons-io and optimize

[msand]

No description provided.

[pke]

@IgorBelyayev what do you think? Could this be merged?
It would also get rid of the gradle warning

WARNING: Configuration 'provided' is obsolete and has been replaced with 'compileOnly'.
It will be removed in version 5.0 of the Android Gradle plugin.
For more information, see http://d.android.com/r/tools/update-dependency-configurations.html.
WARNING: Configuration 'compile' is obsolete and has been replaced with 'implementation' and 'api'.
It will be removed in version 5.0 of the Android Gradle plugin.