Dagger2 best practices I think :)

ApplicationComponent.java

@Singleton
@Component(
        modules = {
                AppModule.class
        })
public interface ApplicationComponent {

    void inject(MainActivity target);

    final class Initializer {

        private Initializer() {}

        public static ApplicationComponent init(MyApplication app) {
            return DaggerApplicationComponent.builder()
                   .appModule(new AppModule(app))
                   .build();
        }
    }
}

Dinner.java

@Singleton
public class Dinner {
  // codes...
}

MainActivity.java

public class MainActivity extends AppCompatActivity{

    @Inject
    Dinner dinner;

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

        ((MyApplication) getApplication()).getApplicationComponent().inject(this);
    }
}

MyApplication.java

public class MyApplication extends Application {

    private ApplicationComponent applicationComponent;

    public ApplicationComponent getApplicationComponent() {
        return applicationComponent;
    }

    @Override
    public void onCreate() {
        super.onCreate();

        applicationComponent = ApplicationComponent.Initializer.init(this);
    }
}