Bdtjtk

I am trying to inject objects that are singletons to 2 activity.

My problem is, Milk and Coffee object after @Inject are null into Activity.
In my opinion I miss something.

Please help me and tell me what is missing in the code

AppComponent:

@Singleton

@Component(modules = {CoffeeModule.class, MilkModule.class})

public interface AppComponent {



    @Component.Builder

    interface Builder {

        @BindsInstance

        Builder appModule(MyMvpApp myMvpApp);



        AppComponent build();



    }

    void inject(MyMvpApp app);

}

CoffeeModule:

@Module

public class CoffeeModule {



    @Provides

    @Singleton

    Coffee getCoffee(){

        return new Coffee();

    }



}

MilkModule:

@Module

public class MilkModule {



    @Provides

    @Singleton

    Milk getMilk(){

        return new Milk();

    }



}

My class App:

public class MyMvpApp extends Application{



    @Override

    public void onCreate() {

        super.onCreate();

        initDagger();

    }



    private void initDagger() {

        AppComponent appComponent = DaggerAppComponent.builder()

                .appModule(this)

                .build();

        appComponent.inject(this);

    }



}

And my Activity on which these objects are null:

public class LoginActivity extends AppCompatActivity {



    @Inject

    Milk milk;



    @Inject

    Coffee coffee;



    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_login);

        Log.i("tag", "" + milk + coffee);

    }

}

@Singleton

@Component(modules = {CoffeeModule.class, MilkModule.class})

public interface AppComponent {



  void inject(LoginActivity app);



  @Component.Builder

  interface Builder {

    @BindsInstance

    Builder appModule(MyMvpApp myMvpApp);



    AppComponent build();

  }

}







public class LoginActivity extends AppCompatActivity {

  @Inject

  Milk milk;



  @Inject

  Coffee coffee;



  @Override

  protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);

    DaggerAppComponent.builder().appModule((MyMvpApp) getApplicationContext()).build().inject(this);

    Log.i("tag", "" + milk + coffee);

  }

}





public class MyMvpApp extends Application {



  @Override

  public void onCreate() {

    super.onCreate();

    initDagger();

  }



  private void initDagger() {

    AppComponent appComponent = DaggerAppComponent.builder()

        .appModule(this)

        .build();

  }

}

You have to add two more lines inside your AppComponent class.

void inject(MyMvpApp app);



//you need to provide milk and coffee here

Milk getMilk();

Coffee getCoffee();

Edit 1 : one more thing you need to inject your activity too in the app component.

void inject(LoginActivity loginActivity);

and call the initDagger method in the activity in the same way you are doing in your Application class.

Edit 2 :If you dont want to repeat the whole thing,then create one method in your application class like this:

 private AppComponent appComponent ;



 public AppComponent getAppComponent(){

  if (appComponent == null) {

        appComponent = DaggerAppComponent.builder()

            .appModule(this)

            .build();

    }

    return appComponent;

}



 public void initDagger(){

  appComponent.inject(this);

}

Inside onCreate of Application class, call these methods.

getAppComponent();

initDagger();

Inside your activity, you can do like this rather than initializing the whole module again and again.

public void initDagger(){

getApplication().getAppCompoment().inject(this);

}