How to update a ProgressBar and stop It when I want?

Question

In first, I'm using Eclipse IDE. So my question is: I create a progress bar, but I want to make it load according to the place where the program is. I have a refresh button, and when I click it my entire program update. What I want is a progress bar that accompanying the process of updating and ends when it ends.

Sorry if my English isn't the best, but I'm a young Portuguese developer.

my btn code

JButton btnActualizar = new JButton("\u21BB");
    btnActualizar.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent arg0) {


            TxtIpExternoLoja.setText(" ");
            TxtSSIDLoja.setText(" ");
            TxtFirewallLoja.setText(" ");

            TxtIpLojaEtho.setText(" ");
            TxtMaskLojaEtho.setText(" ");
            TxtGWLojaEtho.setText(" ");
            TxtDns1LojaEtho.setText(" ");
            TxtDns2LojaEtho.setText(" ");

            TxtIpLojaWlan.setText(" ");
            TxtMaskLojaWlan.setText(" ");
            TxtGwLojaWlan.setText(" ");
            TxtDns1LojaWlan.setText(" ");
            TxtDns2LojaWlan.setText(" ");

            TxtIpLojaVpn.setText(" ");
            TxtMaskLojaVpn.setText(" ");
            TxtGwLojaVpn.setText(" ");
            TxtDns1LojaVpn.setText(" ");
            TxtDns2LojaVpn.setText(" ");

            // DefaultTableModel model = (DefaultTableModel)
            // tablePing.getModel();
            // model.setRowCount(0);
            TxtTime.setText(" ");

            i = 0;
            t.start();
            btnActualizar.setEnabled(false);
            update();

        }
    });

my progressbar code:

JProgressBar progressBar = new JProgressBar(0, 15);
    GridBagConstraints gbc_progressBar = new GridBagConstraints();
    gbc_progressBar.insets = new Insets(0, 0, 0, 5);
    gbc_progressBar.gridx = 3;
    gbc_progressBar.gridy = 0;
    PanelBotoes.add(progressBar, gbc_progressBar);
    GridBagConstraints gbc_btnImprimir = new GridBagConstraints();
    gbc_btnImprimir.insets = new Insets(0, 0, 0, 5);
    gbc_btnImprimir.gridx = 5;
    gbc_btnImprimir.gridy = 0;
    PanelBotoes.add(btnImprimir, gbc_btnImprimir);
    progressBar.setStringPainted(true);
    progressBar.setValue(0);

    t = new Timer(interval, new ActionListener() {
        public void actionPerformed(ActionEvent ae) {
            if (i == 15) {
                t.stop();
                btnActualizar.setEnabled(true);
            } else {
                i++;
                progressBar.setValue(i);
            }
        }
    });

Answer 1

Take a look at this page: https://docs.oracle.com/javase/tutorial/uiswing/components/progress.html.

Specifically, the section on "Using Determinate Progress Bars" should be what you are looking for. The example code is a little complex, but probably about as simple as it can get with this stuff.

Take note: the example uses a SwingWorker (more on those here) to update the progress value. This is because the progress bar is drawn in the Swing thread and won't be updated if the process is running on that thread too. You will need to update your program on a thread which is not the Swing thread.

---

Edit 1 - For your question update with code

So it looks like you've got the idea with the progress bar code. I've not run it, but what you've got looks like it should work. Your next step is to replace the timer with the update() methods process. To do this you'll need to do the following:

1. Make sure your update() method is running in a thread separate from the swing thread (something like a SwingWorker could be used here).
2. From within the update thread you need to call progressBar.setValue(x) when you want to update the bar, where x = how far your process has got.
3. Add some more calls to progressBar.setValue(x) in the update thread. You can put these wherever you like, but it's probably best to put them before and after long processes.

Note: you have to use threads for progress bars. This means you could run into things like deadlock and race conditions. Be careful!