Cannot resolve mediaplayer$onpreparedlistener

Hi
I am trying to add play/pause/stop to audio file stored in assets folder
the file is to be played from html file in webview. when i tried putting
the code together i am getting this error "cannot resolve MediaPlayer$OnPreparedListener"
see my code below

@JavascriptInterface
public void playAudio(final String s) {
if (this.mp != null) {
if (this.mp.isPlaying()) {
this.mp.pause();
}
else {
this.mp.start();
}
}
else {
try {
final AssetFileDescriptor openFd = this.mContext.getAssets().openFd(s);
(this.mp = new MediaPlayer()).setDataSource(openFd.getFileDescriptor(), openFd.getStartOffset(), openFd.getLength());
openFd.close();
this.mp.prepare();
this.mp.setOnPreparedListener((MediaPlayer$OnPreparedListener)new MediaPlayer$OnPreparedListener() {
public void onPrepared(final MediaPlayer mediaPlayer) {
}
});
this.mp.start();
}
catch (IllegalArgumentException ex) {
Log.e(this.TAG, "Err-1: " + ex.toString());
ex.printStackTrace();
}
catch (IllegalStateException ex2) {
Log.e(this.TAG, "Err-2: " + ex2.toString());
ex2.printStackTrace();
}
catch (IOException ex3) {
Log.e(this.TAG, "Err-3: " + ex3.toString());
ex3.printStackTrace();
}
}
}
Kindly help