JavaFX, how do Label and Progressbar update during the method?

[rielyn]

I have a static method of downloading the file:

public class Downloader {
    private static MainLayoutController mlController;
    private static int doneQuantity = 0;
public static void setController(MainLayoutController c) {
    mlController = c;
}

public static void downloadFile(String url, String savePath, int buffSize) {
    try {
        /* Get connection */
        URL connection = new URL(url);
        HttpURLConnection urlconn;

        urlconn = (HttpURLConnection) connection.openConnection();
        urlconn.setRequestMethod("GET");
        urlconn.connect();

        /* Set input stream */
        InputStream in = null;

        in = urlconn.getInputStream();

        /* Find file full path */
        String[] tempArr = url.split("/");

        String fullPath = savePath + tempArr[tempArr.length - 1];

        /* Set Labels */
        //mlController.downloadingLabel.setText(tempArr[tempArr.length - 1]);
        //mlController.downloadedLabel.setText(doneQuantity + "/" + mlController.quantity);
        /*Task task = new Task() {
            @Override
            protected Integer call() throws Exception {
                Platform.runLater(() -> updateTitle(tempArr[tempArr.length - 1]));

                return 101;
            }
        };
        mlController.downloadingLabel.textProperty().bind(task.titleProperty());
        new Thread(task).start();*/

        /* Set write stream */
        OutputStream writer = new FileOutputStream(fullPath);
        byte buffer[] = new byte[buffSize]; // Max bytes per one reception

        /* Download */
        int i = 0;
        double getted_b = 0.0;
        long delta_t = System.nanoTime(), i_sum = 0;

        while ((i = in.read(buffer)) > 0) {
            getted_b += i;
            i_sum += i;

            writer.write(buffer, 0, i);

            if ((System.nanoTime() - delta_t) >= 1E9) { // If the second was over
                int kb, mb;

                mb = new Double(getted_b / (1024 * 1024)).intValue();
                kb = new Double((getted_b / 1024) % 1024).intValue();

                System.out.println(" >> Speed: " + mb + " " + kb + " Mb/sec");
                System.out.println(" >> " + i_sum / (urlconn.getContentLength() / 100) + "%");

                delta_t = System.nanoTime(); // Set to zero
                getted_b = 0.0;
            }
        }

        /* Cleaning */
        writer.flush();
        writer.close();
        in.close();
    } catch (IOException e) {
        System.out.println(e);
    }
}

}

He gets access. label- Mm-hmm. progressbar- and by reference to the controller class. mlController♪ My unsuccessful attempts to update the labels follow the comment. /* Set Labels */♪
Can you tell me how to do this?

[jeanid]

The main idea is that your downloadFile method should be generated in a separate flow rather than in JavaFX Application Thread, and changes to UI elements should be made in Platform.runLater() - ... }. It is possible to go further and make a separate Task Force that carries out all the work and has a message and progress that can be combined.

public class App extends Application {
public static void main(String[] args) throws Exception {

launch(args);

}
public void start(Stage stage) throws Exception {

VBox rootNode = new VBox();
Label label = new Label();
ProgressIndicator progressIndicator = new ProgressIndicator();
Button button = new Button();

button.setOnAction((e) -> {
    DownloadTask downloadTask = new DownloadTask();

    label.textProperty().bind(downloadTask.messageProperty());
    progressIndicator.progressProperty().bind(downloadTask.progressProperty());

    Thread th = new Thread(downloadTask);
    th.setDaemon(true);
    th.start();
});

rootNode.getChildren().add(label);
rootNode.getChildren().add(progressIndicator);
rootNode.getChildren().add(button);

Scene scene = new Scene(rootNode, 400, 200);
stage.setTitle("App");
stage.setScene(scene);
stage.show();

}
class DownloadTask extends Task<Void> {
@Override
protected Void call() throws Exception {
    for (int i = 0; i &lt; 100; i++) {

        updateMessage("Progress " + i);
        updateProgress(i, 100);

        Thread.sleep(10);
    }

    return null;
}

}

♪