Java - Progress Bar Not Progressing

Question

All the coding runs, my only problem is that the progress bar doesn't display the value changes. I set the values, but if I run it the value set, doesn't display on the progress bar. (The bar doesn't fill up)

public void logIn() {
    try {
        while (true) {
            calculate();
            System.out.println(loadingProgress);
            if (loadingProgress < 100) {
                mGUI.pbLoading.setValue(loadingProgress);
                Thread.sleep(random.nextInt(5000) + 100);
            } else {
                mGUI.pbLoading.setValue(100);
                break;
            }
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

public void calculate() {
    random = new Random();
    loadingProgress = loadingProgress + random.nextInt(9) + 1;
}

Answer 1

The calculation has to be done in an extra thread. This is because the currently running thread is blocking the repaint of the UI until the calculation is done.