Question

I can run a bat file in java, I can also get it to send info to java.

Code to run the bat file below. I think i can use an input stream to somehow get progress. I was also thinking maybe I could leave things in the bat file for it to read to get status.

I am hoping someone can give me some code on how to add a basic progress bar to this. I read the demo and examples from oracle but they don’t cover get progress from a bat file.

I updated my code below, I still need to run it and get the line count for the true 100% completion. However, it’s not showing the progress like I thought it would. It runs and stays at 0%, I can tell it’s running still because of task manager.

public class ProgressBar extends JPanel
                          implements ActionListener, 
                                     PropertyChangeListener {

private JProgressBar progressBar;
private JButton startButton;
private JTextArea taskOutput;
private Task task;

class Task extends SwingWorker<Void, Void> {
    /*
     * Main task. Executed in background thread.
     */
    @Override
    public Void doInBackground() {
        Random random = new Random();
        int progress = 0;
        //Initialize progress property.
        setProgress(0);
        //Sleep for at least one second to simulate "startup".
        try {
            Thread.sleep(1000 + random.nextInt(2000));
        } catch (InterruptedException ignore) {}
       // while (progress < 100) {
            //Sleep for up to one second.
            try {
                Thread.sleep(random.nextInt(1000));
            } catch (InterruptedException ignore) {}
            //Make random progress.
            try { 
                String ls_str;   
                Process ls_proc = Runtime.getRuntime().exec("\\WMIRebuild.bat"); 
            //     get its output (your input) stream    
                DataInputStream ls_in = new DataInputStream( 
                    ls_proc.getInputStream()); 
                try { 
                while ((ls_str = ls_in.readLine()) != null) { 
                    System.out.println(ls_str);
                    progress++;
                    } 
                } catch (IOException e) {
                System.exit(0); 
                } 
            } catch (IOException e1) { 
                System.err.println(e1); 
                System.exit(1); 
            }
            setProgress(Math.min(progress, 100));
       // }
        return null;
    }

    /*
     * Executed in event dispatch thread
     */
    public void done() {
        Toolkit.getDefaultToolkit().beep();
        startButton.setEnabled(true);
        taskOutput.append("Done!\n");
    }
}

public ProgressBar() {
    super(new BorderLayout());

    //Create the demo's UI.
    startButton = new JButton("Start");
    startButton.setActionCommand("start");
    startButton.addActionListener(this);

    progressBar = new JProgressBar(0, 18);
    progressBar.setValue(0);

    //Call setStringPainted now so that the progress bar height
    //stays the same whether or not the string is shown.
    progressBar.setStringPainted(true); 

    taskOutput = new JTextArea(5, 20);
    taskOutput.setMargin(new Insets(5,5,5,5));
    taskOutput.setEditable(false);

    JPanel panel = new JPanel();
    panel.add(startButton);
    panel.add(progressBar);

    add(panel, BorderLayout.PAGE_START);
    add(new JScrollPane(taskOutput), BorderLayout.CENTER);
    setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20));
}

/**
 * Invoked when the user presses the start button.
 */
public void actionPerformed(ActionEvent evt) {
    progressBar.setIndeterminate(true);
    startButton.setEnabled(false);
    //Instances of javax.swing.SwingWorker are not reusuable, so
    //we create new instances as needed.
    task = new Task();
    task.addPropertyChangeListener(this);
    task.execute();
}

/**
 * Invoked when task's progress property changes.
 */
public void propertyChange(PropertyChangeEvent evt) {
    if ("progress" == evt.getPropertyName()) {
        int progress = (Integer) evt.getNewValue();
        progressBar.setIndeterminate(false);
        progressBar.setValue(progress);
        taskOutput.append(String.format(
                    "Completed %d%% of task.\n", progress));
    }
}

/**
 * Create the GUI and show it. As with all GUI code, this must run
 * on the event-dispatching thread.
 */
private static void createAndShowGUI() {
    //Create and set up the window.
    JFrame frame = new JFrame("ProgressBarDemo2");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    //Create and set up the content pane.
    JComponent newContentPane = new ProgressBar();
    newContentPane.setOpaque(true); //content panes must be opaque
    frame.setContentPane(newContentPane);

    //Display the window.
    frame.pack();
    frame.setVisible(true);
}

public static void main(String[] args) {
    //Schedule a job for the event-dispatching thread:
    //creating and showing this application's GUI.
    javax.swing.SwingUtilities.invokeLater(new Runnable() {
        public void run() {
            createAndShowGUI();
        }
    });
}

}

Answer 1

Have the progress bar’s frame separate from your main() method. Have it run on a thread of its own. As you read stuff from the batch file ls_in.readLine(), update the progress in the other frame. For example, you can have a method in your frame called addTick() which adds another block to the progress bar, that can be called each time you read a line from your batch file.

---

very rudimentary example:

Thread that reads from process:

    while ((ls_str = ls_in.readLine()) != null) { 
        System.out.println(ls_str);
        progressBar.addTick();
    } 

Progress Bar, runs on its own thread:

    String bar = "#";

    public void addTick()
    {
        if(bar.length() < maxBarLength) {
            bar = bar + "#";
            drawBar(bar);
        }
    }

    public void draw()
    {
        drawBar(bar);
    }

    public void paint()
    {
        // draw some stuff
        draw(bar);
    }

I don’t know, something like that. Obviously the progress bar is going to be different from this, this is just pseudo-code to give you an idea of how the main() method interacts with the progress bar.