Showing batch file execution via swing progress bar

Question

I am trying to execute a batch file and showing its progress through swing progress bar. But stdout.readLine() is returning null. I want to show the output but my InputStream is null. Any suggestion or any other way to do this?

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.event.*;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import javax.swing.*;

public class SwingWorkerExample {

    private final JLabel statusLabel = new JLabel("Status: ", JLabel.CENTER);
    private final JTextArea textArea = new JTextArea(20, 20);
    private JButton startButton = new JButton("Start");
    private JButton stopButton = new JButton("Stop");
    private JProgressBar bar = new JProgressBar();
    private BackgroundTask backgroundTask;
    private final ActionListener buttonActions = new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent ae) {
            JButton source = (JButton) ae.getSource();
            if (source == startButton) {
                textArea.setText(null);
                startButton.setEnabled(false);
                stopButton.setEnabled(true);
                backgroundTask = new BackgroundTask();
                backgroundTask.execute();
                bar.setIndeterminate(true);
            } else if (source == stopButton) {
                backgroundTask.cancel(true);
                backgroundTask.done();
            }
        }
    };

    private void displayGUI() {
        JFrame frame = new JFrame("Swing Worker Example");
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);

        JPanel panel = new JPanel();
        panel.setBorder(
            BorderFactory.createEmptyBorder(5, 5, 5, 5));
        panel.setLayout(new BorderLayout(5, 5));

        JScrollPane sp = new JScrollPane();
        sp.setBorder(BorderFactory.createTitledBorder("Output: "));
        sp.setViewportView(textArea);

        startButton.addActionListener(buttonActions);
        stopButton.setEnabled(false);
        stopButton.addActionListener(buttonActions);
        JPanel buttonPanel = new JPanel();
        buttonPanel.add(startButton);
        buttonPanel.add(stopButton);
        buttonPanel.add(bar);

        panel.add(statusLabel, BorderLayout.PAGE_START);
        panel.add(sp, BorderLayout.CENTER);
        panel.add(buttonPanel, BorderLayout.PAGE_END);

        frame.setContentPane(panel);
        frame.pack();
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }

    private class BackgroundTask extends SwingWorker<Integer, String> {

        private int status;

        public BackgroundTask() {
            System.out.println("state:: "+(this.getState()).toString());
            statusLabel.setText((this.getState()).toString());
        }

        @Override
        protected Integer doInBackground() {

            String[] command = { "cmd.exe", "/C", "Start",
                    "D:\\BackupScripter_cmd_stream.bat" };

            try {
                ProcessBuilder pb = new ProcessBuilder(command);
                pb.redirectErrorStream(true);
                Process p = pb.start();

                //Process p = Runtime.getRuntime().exec(command);
                //System.out.println("exit value: "+ p.exitValue()); 

                String s;
                BufferedReader stdout = new BufferedReader(
                    new InputStreamReader(p.getInputStream()));

                System.out.println("s:: "+stdout.readLine());

                while ((s = stdout.readLine()) != null && !isCancelled()) {
                    System.out.println("s:: "+s);
                    publish(s);
                }
                if (!isCancelled()) {
                    status = p.waitFor();
                }
                p.getInputStream().close();
                p.getOutputStream().close();
                p.getErrorStream().close();
                p.destroy();
            } catch (IOException | InterruptedException ex) {
                ex.printStackTrace(System.err);
            }

            return status;
        }

        @Override
        protected void process(java.util.List<String> messages) {

            System.out.println("messages:: "+messages);
            statusLabel.setText((this.getState()).toString());
            for (String message : messages) {
                textArea.append(message + "\n");
            }
        }

        @Override
        protected void done() {
            statusLabel.setText((this.getState()).toString() + " " + status);
            stopButton.setEnabled(false);
            startButton.setEnabled(true);
            bar.setIndeterminate(false);
        }

    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                new SwingWorkerExample().displayGUI();
            }
        });
    }
}

Answer 1

Issue solved by OP "by removing start as below":

String command = "cmd.exe , /C, D:\\BackupScripter_cmd_stream.bat";
ProcessBuilder pb = new ProcessBuilder(command);