import android.app.*;
import android.media.*;
import android.net.*;

// do not call in ui thread.
// waits until playback done.

static void androidPlayMp3(Activity androidContext, File mp3) {
  final MediaPlayer mPlayer = MediaPlayer.create(androidContext, Uri.fromFile(mp3));
  
  final new Flag done;
  mPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
    public void onCompletion(MediaPlayer mp) {
      mPlayer.release();
      done.raise();
    }
  });

  mPlayer.start();
  done.waitUntilUp();
}

Began life as a copy of #1001270