I created a Preloader (based on the following tutorial) that should display a splash screen for the main application.
9.3.4 Using a Preloader to Display the Application Initialization Progress http://docs.oracle.com/javafx/2/deployment/preloaders.htm
public class SplashScreenLoader extends Preloader {
    private Stage splashScreen;
    @Override
    public void start(Stage stage) throws Exception {
        splashScreen = stage;
        splashScreen.setScene(createScene());
        splashScreen.show();
    }
    public Scene createScene() {
        StackPane root = new StackPane();
        Scene scene = new Scene(root, 300, 200);
        return scene;
    }
    @Override
    public void handleApplicationNotification(PreloaderNotification notification) {
        if (notification instanceof StateChangeNotification) {
            splashScreen.hide();
        }
    }
}
I'd like to run preloader each time I run the main application in my IDE (IntelliJ IDEA).
I also followed the packaging rules for preloaders in IntelliJ: https://www.jetbrains.com/idea/help/applications-with-a-preloader-project-organization-and-packaging.html
When I run the main application the preloader doesn't start, so I suppose I'm missing something. I'm new to Preloaders and I don't understand what is the mechanism to connect the main app with the preloader in standalone application.