Question

This is my first attempt at creating a service and incorporating it in my application. For some reason, I can’t call any of the public methods (for the location).

The Activity

public class MileageActivityV2 extends Activity {
    MileageService mService;
    Boolean mBound;

    @Override
    public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.example_activity);
    }

    @Override
    protected void onStart() {
    super.onStart();

    // bind to MileageService
    Intent intent = new Intent(this, MileageService.class);
    bindService(intent, mConnection, Context.BIND_AUTO_CREATE);

    mService.getCurrentLocation();
    }

    @Override
    protected void onStop() {
    super.onStop();

    // unbind from the service
    if (mBound) {
        unbindService(mConnection);
        mBound = false;
    }
    }

    private ServiceConnection mConnection = new ServiceConnection() {
    @Override
    public void onServiceConnected(ComponentName className, IBinder service) {
        // get the MileageService instance
        LocalBinder binder = (LocalBinder) service;
        mService = binder.getService();
        mBound = true;
    }

    @Override
    public void onServiceDisconnected(ComponentName arg0) {
        mBound = false;
    }
    };
}

The Service

public class MileageService extends Service implements IMileageService{

    private final IBinder binder = new LocalBinder();
    private List<Location> allLocations;
    private Location startLocation;
    private Location lastLocation;
    private Location currentLocation;
    private float totalDistance = 0;
    NotificationManager nMgr;

    /**
     * Class used for the client Binder. Since we know this service always runs
     * in the same process as the clients, dealing with IPC is not necessary.
     */
    public class LocalBinder extends Binder {
    public MileageService getService() {
        // return this instance of MileageService so clients can call public methods
        return MileageService.this;
    }
    }

    @Override
    public void onCreate() {
    nMgr = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);

    // display a notification about the service starting
    showNotification();
    }

    @Override
    public void onDestroy() {
    // cancel the persistent notification
    nMgr.cancel(R.string.mileage_service_started);

    // tell the user we stopped
    Toast.makeText(this, R.string.mileage_service_stopped, Toast.LENGTH_SHORT).show();
    }

    @Override
    public IBinder onBind(Intent intent) {
    return binder;
    }

    /**
     * Show a notification while this service is running.
     */
    private void showNotification() {
    // In this sample, we'll use the same text for the ticker and the
    // expanded notification
    CharSequence text = getText(R.string.mileage_service_started);

    // Set the icon, scrolling text and timestamp
    Notification notification = new Notification(R.drawable.car_1, text, System.currentTimeMillis());

    // The PendingIntent to launch our activity if the user selects this
    // notification
    PendingIntent contentIntent = PendingIntent.getActivity(this, 0, new Intent(this, MileageActivity.class), 0);

    // Set the info for the views that show in the notification panel.
    notification.setLatestEventInfo(this, getText(R.string.mileage_service_started), text, contentIntent);

    // Send the notification.
    // We use a string id because it is a unique number. We use it later to
    // cancel.
    nMgr.notify(R.string.mileage_service_started, notification);
    }

    private static final int BUMP_MSG = 1;

    private Handler mHandler = new Handler() {

    @Override
    public void handleMessage(Message msg) {
        switch (msg.what) {
        case BUMP_MSG:
        break;
        default:
        super.handleMessage(msg);
        }
    }
    };

    @Override
    public List<Location> getLocations() {
    return this.allLocations;
    }

    @Override
    public Location getCurrentLocation() {
    return this.currentLocation;
    }

    @Override
    public Location getStartLocation() {
    return this.startLocation;
    }

    @Override
    public Location getLastLocation() {
    return this.lastLocation;
    }

    @Override
    public Float getDistance() {
    return this.totalDistance;
    }
}

Answer 1

Your issue is that in your onStart method, your service hasn’t actually started. The call

Intent intent = new Intent(this, MileageService.class);
bindService(intent, mConnection, Context.BIND_AUTO_CREATE);

is asynchronous. You need to wait for the service to become bound before you call any methods on this. There are many ways to do that, but the quickest would be to add the call mService.getCurrentLocation(); to the end of the onServiceConnected method. Note that this is going to run on the main thread of the app so don’t do blocking operations on it.

As you get further along, you may find that you need to kick off an async task from the end of teh connection to do all the work you want without affecting the ui. There are examples of that around the web.