import java.awt.Color;
import javafx.application.Application;
import javafx.embed.swing.SwingNode;
import javafx.scene.Scene;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
import javax.swing.JButton;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;


public final class Test extends Application {

    public static void main(String[] args) {
        launch(args);
    }

    private void initSwing(final SwingNode swingNode) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                JPanel panel = new JPanel();
                JButton button = new JButton("Ok");
                button.setBackground(Color.RED);
                panel.add(button);
                swingNode.setContent(panel);
            }
        });
    }

    @Override
    public void start(Stage stage) throws Exception {
        final SwingNode swingNode = new SwingNode();
        initSwing(swingNode);
        StackPane pane = new StackPane();
        pane.setStyle("-fx-background-color: #00FF00");
        pane.getChildren().add(swingNode);

        Scene scene = new Scene(pane, 300, 300);

        stage.setScene(scene);
        stage.setTitle("Button Embedded in JavaFX");
        stage.show();
    }
}