Java – Using JavaFX Chart in Swing Application

See the 'JavaFX in Swing' tutorial. You are performing JavaFX operations which should run on the JavaFX thread on the Swing thread (Event Dispatch Thread).

Luckily they learnt from their previous mistakes and now throw exceptions when you perform operations on the wrong thread. That is the exception you encountered.

Use the Platform#runLater as shown in that tutorial

Platform.runLater(new Runnable() {
        @Override
        public void run() {
          //javaFX operations should go here
        }
   });

The construction of the JFXPanel can remain on the EDT (which is also illustrated in that tutorial)

Took your code, turned it into a SSCCE - everything seems to work, which would indicate the problem is elsewhere in your code. Can you reproduce your problem using this code?

import java.awt.Color;
import java.awt.Container;
import javafx.application.Platform;
import javafx.embed.swing.JFXPanel;
import javafx.scene.*;
import javafx.scene.text.*;
import javax.swing.*;

public class SwingJFXCombo {

    public static Container initialize(){

        final JFXPanel fxPanel = new JFXPanel();
        JPanel jp = new JPanel();

        jp.add(fxPanel);
        jp.setVisible(true);
        // Really shouldn't do this, so commented it out
        //jp.setPreferredSize(new Dimension(500, 300));
        jp.setBackground(Color.CYAN);

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

        return jp;
    }

    private static void initFX(JFXPanel fxPanel) {
        Scene scene = initScene();
        fxPanel.setScene(scene);
    }

    private static Scene initScene(){
        Group  root  =  new  Group();
        Scene  scene  =  new  Scene(root, javafx.scene.paint.Color.ALICEBLUE );
        Text  text  =  new  Text();
        text.setX(40);
        text.setY(100);
        text.setFont(new Font(25));
        text.setText("Welcome JavaFX!");
        root.getChildren().add(text);
        return (scene);
    }

    public static void main(String[] args){
        final JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
        frame.add(SwingJFXCombo.initialize());
        frame.pack();
    }
}