Local Service Binding Code from Activity to Service

Question

The client code for binding to a service, which is normally in the activity class; I'm trying to move it to the service class, so that the activity class would be as clean and small as possible.

i.e. basically trying to merge the code in the second box here into the first box = as much of it into the service class as possible

Single Line in Activity for Binding to Service

public class MyActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    // Bind to service with this line only:
    AService.bindService(this);
}
}

Static bindService and ServiceConnection Moved to Service

public class AService extends Service {

public String test = "I want to see this";
public static AService aService;
private static boolean isBound;
private static Context context;

// ... IBinder, onBind etc also here on service side

public static void bindService(Context context) {
    try {
        Log.i(TAG, "bindService Start");
        if (!isBound && context != null) {
            Log.i(TAG, "Binding");
            context.bindService(new Intent(context, AService.class),
                    serviceConnection, Context.BIND_AUTO_CREATE);
            isBound = true;
            Log.i(TAG, "Bound");
        }
    } catch (Exception e) {
        Log.e(TAG, "bindService", e);
    }
}

private static ServiceConnection serviceConnection = new ServiceConnection() {
    public void onServiceConnected(ComponentName className, IBinder service) {
        try {
            Log.i(TAG, "onServiceConnected Start");
            aService = ((AService.LocalBinder) service).getService();
            if (aService != null)
                Log.i(TAG, aService.test);
            Log.i(TAG, "onServiceConnected Finish");
        } catch (Exception e) {
            Log.e(TAG, "onServiceConnected", e);
        }
    }

    public void onServiceDisconnected(ComponentName className) {
        try {
            Log.i(TAG, "onServiceDisconnected");
            aService = null;
        } catch (Exception e) {
            Log.e(TAG, "onServiceDisconnected", e);
        }
    }
};


public static void unbind() {
    try {
        Log.i(TAG, "unbind start");
        if (isBound && context != null) {
            Log.i(TAG, "Unbinding");
            context.unbindService(serviceConnection);
            isBound = false;
            context = null;
            Log.i(TAG, "Unbound");
        }
    } catch (Exception e) {
        Log.e(TAG, "unbind", e);
    }
}

}

But onServiceConnected is Never Called?

The log shows everything up to:

...
Bound

• But NOT onServiceConnected Start or beyond
• and no exceptions.
• Note that when the same code was in the Activity, it works (when called with MyActivity.this)

What am I doing wrong?

Answer 1

Is this

AService.bindService(this);

much better than this?

bindService(new Intent(context, AService.class),
                serviceConnection, Context.BIND_AUTO_CREATE);

And does ServiceConnection implementation sit in Activity really annoying your so much? I doubt that.

I don't see any point centralize everything into Service and then call a static method in the actual Service to start this Service from Activity. The best practice is to follow the standard way that Google's recommended to do things, by doing this in your way, you make your code obscure and confuse other people when reading your code (if you work in a team). It doesn't make any sense IMO.

Instead of put all your effort into isolate every single bit of service from activity, I would rather consider more on how to isolate business logic from activity and centralize them into service, and let Activity mostly focus on UI stuff.

Really hope that would help you.