Android : Media Player Class in Android the implementation scenario

for last three weeks I have worked on a Media Player in Android.I am trying to find a solution of how can I make my Media Player to change the song when it's already playing one.

Here is my Listener on the RecyclerView

    musicList.addOnItemTouchListener(
            new RecyclerItemClickListener(getApplicationContext(), new RecyclerItemClickListener.OnItemClickListener() {
                @Override
                public void onItemClick(View view, final int position) {

                    currentPosition = position;

                    if(!mediaPlayer.isPlaying()){
                        musicThread.start();
                    } else {
                        mediaPlayer.reset();

                    }

                }
            })
    );
}

and my Thread is this:

    final Thread musicThread = new Thread(new Runnable(){
        @Override
        public void run() {

            try {
                URL = getMusicURL(myDataset[currentPosition]);

                try {
                    mediaPlayer.setDataSource(URL);
                    //mediaPlayer.prepare(); // might take long! (for buffering, etc)
                    mediaPlayer.prepareAsync(); // prepare async to not block main thread
                } catch (IOException e) {
                    e.printStackTrace();
                    Log.i("TEST","Eroare: "+e.getMessage());
                }
            } catch (StorageApiException e) {
                e.printStackTrace();
                Log.i("TEST","Eroare: "+e.getMessage());
            }

        }
    });