LayoutAnnotation

BaseActivity.java

public abstract class BaseActivity extends AppCompatActivity {   
    @LayoutRes int getLayout() {
        int layoutResId =-1;
        Class screenType = getClass();
        Layout layout = (Layout) screenType.getAnnotation(Layout.class);
        if (layout == null) {
            throw new IllegalArgumentException(
                    String.format("@%s annotation not found on class %s", Layout.class.getSimpleName(),
                            screenType.getName()));
        }
        layoutResId = layout.value();
        return layoutResId;
    }
    
    @Override protected void onCreate(@Nullable final Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(getLayout());
    }
}
    

BaseFragment.java

public abstract class BaseFragment extends Fragment {
   protected @LayoutRes int getLayout() {
        int layoutResId = Constants.NO_RESOURCE_KEY;
        Class screenType = getClass();
        Layout layout = (Layout) screenType.getAnnotation(Layout.class);
        if (layout == null) {
            throw new IllegalArgumentException(
                    String.format("@%s annotation not found on class %s", Layout.class.getSimpleName(),
                            screenType.getName()));
        }
        layoutResId = layout.value();
        return layoutResId;
    }
    @Override View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
      mContentView = inflater.inflate(getLayout(), container, false);
      return mContentView;
    }
}

Layout.java

import java.lang.annotation.Retention;
import java.lang.annotation.Target;

import static java.lang.annotation.ElementType.TYPE;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

@Retention(RUNTIME) @Target(TYPE)
public @interface Layout {
    int value();
}