javafx.embed.singleThread=true not working

Hendrik Ebbers hendrik.ebbers at
Mon Feb 3 03:16:30 PST 2014

I’m currently trying the experimental support of the javafx.embed.singleThread flag to mix the EDT and JFX Application Thread. Therefore I created a demo application. But when I start the app the following exception is thrown:
Exception in thread "AWT-EventQueue-0" java.lang.IllegalStateException: Not on FX application thread; currentThread = AWT-EventQueue-0

I think I’m doing something wrong but currently I have no idea why this is not working. Any ideas?

I’m using the folioing JavaFX version:

java version "1.8.0-ea"
Java(TM) SE Runtime Environment (build 1.8.0-ea-b123)
Java HotSpot(TM) 64-Bit Server VM (build 25.0-b65, mixed mode)

Here is the code of the demo application:

public class JFXPanelDemo1 {

    private static JButton swingButton;
    private static Button jfxButton;

    public static void main(String[] args) {

        SwingUtilities.invokeLater(() -> {
            JFrame swingFrame = new JFrame("Integrate JavaFX in Swing");
            swingFrame.getContentPane().setLayout(new BorderLayout());
            swingButton = new JButton("I'm a Swing button");
            swingFrame.getContentPane().add(BorderLayout.NORTH, swingButton);

            swingButton.addActionListener((e) -> {

            JFXPanel jfxPanel = new JFXPanel();
            swingFrame.getContentPane().add(BorderLayout.CENTER, jfxPanel);

            jfxButton = new Button("I'm a JavaFX button");
            StackPane jfxPane = new StackPane(jfxButton);
            Scene jfxScene = new Scene(jfxPane);

            jfxButton.setOnAction((e) -> {



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