AndroId MediaPlayer prepareAsync method

Patrice Cote picture Patrice Cote · Apr 25, 2012 · Viewed 24.9k times · Source

I have a strange problem. I use the prepareAsync method with the MediaPlayer, but the listener that I declared just never gets fired. I try to stream a live .mp3 feed from the Internet (radio station). I use an inline method for the listener, but I also tried implementing the interface without any success. Here's a portion of my code :

In the member section :

String url = "http://<my_url>.mp3";
MediaPlayer mediaPlayer = new MediaPlayer();

In Activity onCreate() :

ToggleButton playButton = (ToggleButton) findViewById(R.id.playToggleButton);
playButton.setOnClickListener(this);
playButton.clearFocus();
playButton.setClickable(false);

mediaPlayer.setOnPreparedListener(new OnPreparedListener() {
    public void onPrepared(MediaPlayer mp) {
        ToggleButton playButton = (ToggleButton) findViewById(R.id.playToggleButton);
        playButton.setClickable(true);
        mp.start();
    }
});

preparePlayer();

Then, here's the preparePlayer() method :

private void preparePlayer() {
    if (mediaPlayer == null) {
        mediaPlayer = new MediaPlayer();
    }
    mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
    try {
        mediaPlayer.setDataSource(url);
        mediaPlayer.prepareAsync();

    } catch (IllegalArgumentException e) {
        Toast.makeText(
                MyStreamActivity.this,
                getResources().getString(R.string.erreurIllegalArgument),
                Toast.LENGTH_LONG).show();
        e.printStackTrace();
    } catch (IllegalStateException e) {
        Toast.makeText(
                MyStreamActivity.this,
                getResources().getString(R.string.erreurIllegalState),
                Toast.LENGTH_LONG).show();
        e.printStackTrace();
    } catch (IOException e) {
        Toast.makeText(
                MyStreamActivity.this,
                getResources().getString(R.string.erreurIO),
                Toast.LENGTH_LONG).show();
        e.printStackTrace();
    }
}

And (just for the record), the onDetroy() where I do the cleaning :

private void releaseMediaPlayer() {
    if (mediaPlayer != null) {
        if(mediaPlayer.isPlaying()) {
            mediaPlayer.stop();
        }
        mediaPlayer.release();
        mediaPlayer = null;
    }
}

@Override
protected void onDestroy() {
    super.onDestroy();
    releaseMediaPlayer();
}

Answer

petey picture petey · Apr 25, 2012

You are setting the OnPreparedListener in your Activity's create method and later on, possibly, creating a new MediaPlayer in your preparePlayer() method. Any newly created MediaPlayer's wont have the prepareListener set. You should also add an errorlistener to find out whats going on.

You may want to move the setOnPreparedListener call inside the

  if (mediaPlayer == null) {
    mediaPlayer = new MediaPlayer();
}

as well as setting a setOnErrorListener like so:

if (mediaPlayer == null) {
    mediaPlayer = new MediaPlayer();
    mediaPlayer.setOnErrorListener(....);
    mediaPlayer.setOnPreparedListener(new OnPreparedListener() {
        public void onPrepared(MediaPlayer mp) {
            ToggleButton playButton = (ToggleButton) findViewById(R.id.playToggleButton);
            playButton.setClickable(true);
            mp.start();
        }
    });
}

Please change e.printStackTrace(); to

Log.e("tag", e.getMessage(), e);  

Hope this helps, let us know if you have any log data as this will also be useful.