How to play mp3 with native code?

Hi Corona developers,

I am working on a music app.

There are mp3 files downloaded in Documents folder, for example : song1.mp3.

Does anyone know what’s the proper way to play this file with media player and audio manger?

MediaPlayer mediaPlayer = MediaPlayer.create(context, ?); mediaPlayer.prepare(); mediaPlayer.start();

How do I use

​public static java.io.File getDocumentsDirectory(android.content.Context context)

in http://docs.coronalabs.com/native/android/html/com/ansca/corona/CoronaEnvironment.html

Thank you.

Keng-Fu