Blogpost example ReactScreen

ReactScreen.java

public class ReactScreen extends Activity implements DefaultHardwareBackBtnHandler {

    protected ReactInstanceManager reactInstanceManager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        reactInstanceManager = ReactInstanceManager.builder()
                .setApplication(this.getApplication())
                .setBundleAssetName("react.android.bundle")
                .setJSMainModulePath("index")
                .addPackage(new MainReactPackage())
                .setUseDeveloperSupport(BuildConfig.DEBUG)
                .setInitialLifecycleState(LifecycleState.RESUMED)
                .build();

        ReactRootView reactRootView = new ReactRootView(this);
        reactRootView.startReactApplication(reactInstanceManager, "Index");
        setContentView(reactRootView);
    }
    
    @Override
    public void invokeDefaultOnBackPressed() {
        super.onBackPressed();
    }

    //Implement other lifecycle methods here and delegate to ReactInstanceManager
}