Playing Music with Android Service

Operations that are time-consuming and suitable for background execution, such as music playback, should be performed in a Service rather than an Activity. Below, we’ll introduce a music player implementation using a Service.

Step 1: Create a MusicService¶

In Android Studio, right-click on the package name, select New → Service → Service.

Create Service

When created this way, the Service declaration is automatically added to the manifest file.

Service Manifest

Step 2: Implement MusicService¶

The MusicService handles music playback logic, overriding onCreate() for player initialization.

public class MusicService extends Service {
    private String path = "mnt/sdcard/123.mp3"; // Local audio file path
    private MediaPlayer player;

    @Override
    public IBinder onBind(Intent intent) {
        return new MyBinder(); // Return control methods to MainActivity
    }

    @Override
    public void onCreate() {
        super.onCreate();
        player = new MediaPlayer();
        try {
            player.setDataSource(path);
            player.prepare(); // Synchronous preparation for local files
        } catch (IOException e) {
            e.printStackTrace();
        }
        Log.e("Service", "Music prepared for playback");
    }

    // Inner class to expose music control methods
    public class MyBinder extends Binder {
        public boolean isPlaying() {
            return player.isPlaying();
        }

        public void play() {
            if (player.isPlaying()) {
                player.pause();
            } else {
                player.start();
            }
            Log.e("Service", "Music playback control triggered");
        }

        public int getDuration() {
            return player.getDuration(); // Duration in milliseconds
        }

        public int getCurrentPosition() {
            return player.getCurrentPosition(); // Current progress in milliseconds
        }

        public void seekTo(int ms) {
            player.seekTo(ms); // Seek to specified position
        }
    }
}

Step 3: Design the Layout¶

Add a button and a progress bar to control playback.

<Button
    android:id="@+id/play"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:onClick="play"
    android:text="Play" />

<SeekBar
    android:id="@+id/sb"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" />

Step 4: Implement MainActivity¶

The Activity binds to MusicService to control playback and update the UI.

public class MainActivity extends AppCompatActivity {
    private MusicService.MyBinder musicControl;
    private Button playBtn;
    private SeekBar seekBar;
    private static final int UPDATE_PROGRESS = 0;
    private Handler handler = new Handler(Looper.getMainLooper()) {
        @Override
        public void handleMessage(Message msg) {
            if (msg.what == UPDATE_PROGRESS) {
                updateProgress();
            }
        }
    };

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

        playBtn = findViewById(R.id.play);
        seekBar = findViewById(R.id.sb);

        // Start and bind to the service
        Intent intent = new Intent(this, MusicService.class);
        startService(intent);
        bindService(intent, new MyConnection(), BIND_AUTO_CREATE);

        // SeekBar listener
        seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            @Override
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
                if (fromUser) {
                    musicControl.seekTo(progress);
                }
            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {}

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {}
        });
    }

    // Service connection to get MyBinder instance
    private class MyConnection implements ServiceConnection {
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            musicControl = (MusicService.MyBinder) service;
            updatePlayText();
            seekBar.setMax(musicControl.getDuration());
            seekBar.setProgress(musicControl.getCurrentPosition());
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {}
    }

    @Override
    protected void onResume() {
        super.onResume();
        if (musicControl != null) {
            handler.sendEmptyMessage(UPDATE_PROGRESS);
        }
    }

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

    @Override
    protected void onStop() {
        super.onStop();
        handler.removeCallbacksAndMessages(null); // Stop progress updates
    }

    // Update progress bar periodically
    private void updateProgress() {
        int current = musicControl.getCurrentPosition();
        seekBar.setProgress(current);
        handler.sendEmptyMessageDelayed(UPDATE_PROGRESS, 500); // Update every 500ms
    }

    // Toggle play/pause and update button text
    public void play(View view) {
        musicControl.play();
        updatePlayText();
    }

    private void updatePlayText() {
        if (musicControl.isPlaying()) {
            playBtn.setText("Pause");
            handler.sendEmptyMessage(UPDATE_PROGRESS);
        } else {
            playBtn.setText("Play");
        }
    }
}

Step 5: Add Permissions¶

Include storage access permission for local files:

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

Effect¶

Music Player Demo

Bonus: Network Music Playback¶

To play music from a URL, use asynchronous preparation and a listener:

private MediaPlayer player;

public void playNetworkMusic() {
    if (player == null) {
        player = new MediaPlayer();
        try {
            player.setDataSource("http://www.w3school.com.cn/i/horse.mp3");
            player.prepareAsync(); // Asynchronous preparation for network files
            player.setOnPreparedListener(mp -> mp.start()); // Start after preparation
        } catch (IOException e) {
            e.printStackTrace();
        }
    } else {
        if (player.isPlaying()) {
            player.pause();
        } else {
            player.start();
        }
    }
}

Add network permission:

<uses-permission android:name="android.permission.INTERNET" />

This implementation separates UI (Activity) from background logic (Service), ensuring smooth music playback without blocking the UI thread.