Re: How to send console progress information to gui

=?windows-1252?Q?Arne_Vajh=F8j?= <>
Sat, 18 May 2013 19:38:47 -0400
On 5/2/2013 2:49 PM, mike wrote:

I am using java to send a commdline arg 'mklabel ?config hello.o REL3'.
The output that I get is a new line for each element a put the label on.
In my application I want to show the user the progress of the command.
Can I create an event that contains the information for each line and send it to a listener? Or is there a better way?

Assuming you use Swing for GUI then see the code below for inspiration.



import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;

public class CommandOutputDisplay extends JFrame {
    private static final long serialVersionUID = 1L;
    private JTextArea out;
    private JTextArea err;
    private JTextField cmd;
    private JButton exe;
    public CommandOutputDisplay() {
         getContentPane().setLayout(new BorderLayout());
         JPanel outerr = new JPanel();
         outerr.setLayout(new GridLayout(1, 2));
         JPanel outwrap = new JPanel();
         outwrap.setLayout(new BorderLayout());
         outwrap.add(new JLabel("Output"), BorderLayout.NORTH);
         out = new JTextArea(20, 80);
         outwrap.add(new JScrollPane(out), BorderLayout.CENTER);
         JPanel errwrap = new JPanel();
         errwrap.setLayout(new BorderLayout());
         errwrap.add(new JLabel("Error"), BorderLayout.NORTH);
         err = new JTextArea(20, 80);
         errwrap.add(new JScrollPane(err), BorderLayout.CENTER);
         getContentPane().add(outerr, BorderLayout.CENTER);
         JPanel cmdexe = new JPanel();
         cmdexe.setLayout(new BorderLayout());
         cmdexe.add(new JLabel("Command:"), BorderLayout.WEST);
         cmd = new JTextField("", 80);
         cmdexe.add(cmd, BorderLayout.CENTER);
         exe = new JButton("Execute");
         exe.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
         cmdexe.add(exe, BorderLayout.EAST);
         getContentPane().add(cmdexe, BorderLayout.SOUTH);
    private void execute() {
        try {
            Process p = Runtime.getRuntime().exec(cmd.getText());
            (new GUIReader(p.getInputStream(), out)).start();
            (new GUIReader(p.getErrorStream(), err)).start();
        } catch (IOException e) {
    public static void main(String[] args) {
         SwingUtilities.invokeLater(new Runnable() {
             public void run() {
                 JFrame f = new CommandOutputDisplay();

class GUIReader extends Thread {
    private BufferedReader br;
    private JTextArea ta;
    public GUIReader(InputStream is, JTextArea ta) { = new BufferedReader(new InputStreamReader(is));
        this.ta = ta;
    public void run() {
        String line;
        try {
            while((line = br.readLine()) != null) {
                final String line2 = line;
                EventQueue.invokeLater(new Runnable() {
                    public void run() {
                        ta.append(line2 + "\r\n");
        } catch (IOException e) {

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