CODEWITHSUNDEEP
androidandroid-servicemediaplaybackforeground
Rico Nguyen
Rico Nguyen

Reputation: 401

Using Android Service to play media

I refer this tut http://code.tutsplus.com/tutorials/create-a-music-player-on-android-user-controls--mobile-22787 to create app to play mp3 file. But when I press back button, playback is stopped. Certainly, on onDestroy() method, I don't implement stop service like this tut.

Thanks for help.

public class MainActivity extends Activity {

    //song list variables
    private ArrayList<Song> songList;
    private ListView songView;

    //service
    private MusicService musicSrv;
    private Intent playIntent;
    //binding
    private boolean musicBound=false;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        //retrieve list view
        songView = (ListView)findViewById(R.id.song_list);
        //instantiate list
        songList = new ArrayList<Song>();
        //get songs from device
        getSongList();
        //sort alphabetically by title
        Collections.sort(songList, new Comparator<Song>(){
            public int compare(Song a, Song b){
                return a.getTitle().compareTo(b.getTitle());
            }
        });
        //create and set adapter
        SongAdapter songAdt = new SongAdapter(this, songList);
        songView.setAdapter(songAdt);
    }

    //connect to the service
    private ServiceConnection musicConnection = new ServiceConnection(){

        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            MusicBinder binder = (MusicBinder)service;
            //get service
            musicSrv = binder.getService();
            //pass list
            musicSrv.setList(songList);
            musicBound = true;
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {
            musicBound = false;
        }
    };

    //start and bind the service when the activity starts
    @Override
    protected void onStart() {
        super.onStart();
        if(playIntent==null){
            playIntent = new Intent(this, MusicService.class);
            bindService(playIntent, musicConnection, Context.BIND_AUTO_CREATE);
            startService(playIntent);
        }
    }

    //user song select
    public void songPicked(View view){
        musicSrv.setSong(Integer.parseInt(view.getTag().toString()));
        musicSrv.playSong();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        //menu item selected
        switch (item.getItemId()) {
        case R.id.action_shuffle:
            //shuffle
            break;
        case R.id.action_end:
            stopService(playIntent);
            musicSrv=null;
            System.exit(0);
            break;
        }
        return super.onOptionsItemSelected(item);
    }

    //method to retrieve song info from device
    public void getSongList(){
        //query external audio
        ContentResolver musicResolver = getContentResolver();
        Uri musicUri = android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
        Cursor musicCursor = musicResolver.query(musicUri, null, null, null, null);
        //iterate over results if valid
        if(musicCursor!=null && musicCursor.moveToFirst()){
            //get columns
            int titleColumn = musicCursor.getColumnIndex
                    (android.provider.MediaStore.Audio.Media.TITLE);
            int idColumn = musicCursor.getColumnIndex
                    (android.provider.MediaStore.Audio.Media._ID);
            int artistColumn = musicCursor.getColumnIndex
                    (android.provider.MediaStore.Audio.Media.ARTIST);
            //add songs to list
            do {
                long thisId = musicCursor.getLong(idColumn);
                String thisTitle = musicCursor.getString(titleColumn);
                String thisArtist = musicCursor.getString(artistColumn);
                songList.add(new Song(thisId, thisTitle, thisArtist));
            } 
            while (musicCursor.moveToNext());
        }
    }

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

}

Music Service

public class MusicService extends Service implements 
MediaPlayer.OnPreparedListener, MediaPlayer.OnErrorListener,
MediaPlayer.OnCompletionListener {

    //media player
    private MediaPlayer player;
    //song list
    private ArrayList<Song> songs;
    //current position
    private int songPosn;
    //binder
    private final IBinder musicBind = new MusicBinder();

    public void onCreate(){
        //create the service
        super.onCreate();
        //initialize position
        songPosn=0;
        //create player
        player = new MediaPlayer();
        //initialize
        initMusicPlayer();
    }

    public void initMusicPlayer(){
        //set player properties
        player.setWakeMode(getApplicationContext(), 
                PowerManager.PARTIAL_WAKE_LOCK);
        player.setAudioStreamType(AudioManager.STREAM_MUSIC);
        //set listeners
        player.setOnPreparedListener(this);
        player.setOnCompletionListener(this);
        player.setOnErrorListener(this);
    }

    //pass song list
    public void setList(ArrayList<Song> theSongs){
        songs=theSongs;
    }

    //binder
    public class MusicBinder extends Binder {
        MusicService getService() { 
            return MusicService.this;
        }
    }

    //activity will bind to service
    @Override
    public IBinder onBind(Intent intent) {
        return musicBind;
    }

    //release resources when unbind
    @Override
    public boolean onUnbind(Intent intent){
        player.stop();
        player.release();
        return false;
    }

    //play a song
    public void playSong(){
        //play
        player.reset();
        //get song
        Song playSong = songs.get(songPosn);
        //get id
        long currSong = playSong.getID();
        //set uri
        Uri trackUri = ContentUris.withAppendedId(
                android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
                currSong);
        //set the data source
        try{ 
            player.setDataSource(getApplicationContext(), trackUri);
        }
        catch(Exception e){
            Log.e("MUSIC SERVICE", "Error setting data source", e);
        }
        player.prepareAsync(); 
    }

    //set the song
    public void setSong(int songIndex){
        songPosn=songIndex; 
    }

    @Override
    public void onCompletion(MediaPlayer mp) {
        // TODO Auto-generated method stub
    }

    @Override
    public boolean onError(MediaPlayer mp, int what, int extra) {
        // TODO Auto-generated method stub
        return false;
    }

    @Override
    public void onPrepared(MediaPlayer mp) {
        //start playback
        mp.start();
    }

}

Upvotes: 0

Views: 4615

Answers (4)

Rico Nguyen
Rico Nguyen

Reputation: 401

Good example for startforeground(): https://github.com/commonsguy/cw-android/tree/master/Notifications/FakePlayer

Good example for interact with service: http://code.tutsplus.com/tutorials/create-a-music-player-on-android-user-controls--mobile-22787

Upvotes: 1

Rico Nguyen
Rico Nguyen

Reputation: 401

God dang it, because the stupid snippet code

@Override
public boolean onUnbind(Intent intent){
    player.stop();
    player.release();
    return false;
}

Upvotes: 0

Muhammad Naderi
Muhammad Naderi

Reputation: 3248

try this:

in the onStartCommand, after your codes for playing mps, return START_STICKY

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    // play mp3 code here
    return START_STICKY;
}

UPDATE AFTER CODE:

You bounded your service to your play intent which is related to your activity, so when you destroy your activity, eq. press back, the service will be unBinded simple solution will be to not bind the service to your activity, and put your services codes in the onBind Section in the onStartCommand and return it as START_STICKY this way your service will continue to run in background until you call DestroySelf() which probably should be called when the music finishes

Upvotes: 0

Rico Nguyen
Rico Nguyen

Reputation: 401

I realize that because I created MusicSrv in MainActivity, when Activity's destroyed MusicSrv gone. But if I do not create MusicSrv in MainActivity, how can I set list song or put MainActivity into MusicSrv to update UI.

Upvotes: 0

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