Application

public class App extends DaggerApplication {

    @Inject
    OnFirstRunUseCase onFirstRunUseCase;

    @Override
    public void onCreate() {
        super.onCreate();
        ((AppComponent) applicationInjector()).inject(app); //solving
        onFirstRunUseCase.execute(() -> {}, throwable -> {});
    }

    @Override
    protected AndroidInjector<? extends DaggerApplication> applicationInjector() {
        return DaggerAppComponent
                .builder()
                .application(this)
                .build();
    }
}



//----Logcat Output----//
java.lang.RuntimeException: Unable to create application xx.xx.xxx.App: 
java.lang.NullPointerException: Attempt to invoke virtual method 
'void OnFirstRunUseCase.execute(io.reactivex.functions.Action, 
io.reactivex.functions.Consumer)' on a null object reference