http://st-doc.us.oracle.com/review/rsb/html/E20483_01/jfxpub-swing.htm

Example 1

public class Test {

    private static void initAndShowGUI() {
        // This method is invoked on the EDT thread
        JFrame frame = new JFrame("FX");
        final JFXPanel fxPanel = new JFXPanel();
        frame.add(fxPanel);
        frame.setVisible(true);

        Platform.runLater(new Runnable() {
            @Override
            public void run() {
            initFX(fxPanel);
            }
       });
    }

    private static void initFX(JFXPanel fxPanel) {
        // This method is invoked on the JavaFX thread
        Scene scene = createScene();
        fxPanel.setScene(scene);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
            initAndShowGUI();
            }
        });
    }
}

Scene scene = createScene(); = It is not known by IDE where to take this code from.