How to update fxml Label from a background worker?

Question

I have a label in my fxml file:

<Label fx:id="labelA"/>

I want to update this in the controller during a background worker is executing. I have tried to do something like this:

public class FXHelloCVController
{
    @FXML
    private Label labelA;
    @FXML
    protected void startMatching(ActionEvent event)
    {   
        SwingWorker<Boolean, String> worker = new SwingWorker<Boolean, String>()
        {
            @Override
            protected Boolean doInBackground() throws Exception
            {

                for(int y=0; y<*something*; y++){
                    if(n.get(y)!=null){
                        ...
                        publish(n.get(y).name);
                        ...
                    }
                }
                return true;
            }

            @Override
            protected void process(List<String> chunks) {
                String n = chunks.get(chunks.size()-1);
                labelA.setText(n);
            }
        };
        worker.execute();
        return;
    }

But when the function "labelA.setText(n)" is called, it appears the following exception:

Exception in thread "AWT-EventQueue-0" java.lang.IllegalStateException: Not on FX application thread; currentThread = AWT-EventQueue-0

What is wrong?

Gianna don't mix Swing with JavaFX instead of this java has something very nice which is Service and Worker classes have a look here:http://docs.oracle.com/javafx/2/threads/jfxpub-threads.htm (it is not too easy to learn at once but once you do is really cool). — GOXR3PLUS, May 22 '16 at 18:06

score 2 · Accepted Answer · edited May 23 '17 at 10:28

Platform.runLater: If you need to update a GUI component from a non-GUI thread, you can use that to put your update in a queue and it will be handle by the GUI thread as soon as possible.

    Platform.runLater(new Runnable() {
        @Override public void run() {
            // update an FXML node (e.g. label)
        }
    });

Source: Platform.runLater and Task in JavaFX

But you're using Swing and JavaFX, which isn't usually.

score 1 · Answer 2 · answered May 22 '16 at 11:43

1

A SwingWorker is for Swing and not for JavaFX. Have a look at the documentation for the corresponding JavaFX concurrency mechanisms.

answered May 22 '16 at 11:43

mipa

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How to update fxml Label from a background worker?

2 Answers2