1. Java Remote Debug
With Eclipse
Nov.23.2013
Boy.Wang

2. Introduction
Debugee
JVM
Debugger
JDWP
1. Debugee
Java application run on JVM with specific parameters.
2. Debugger
An editor or IDE support JDWP (Java Debug Wire Protocol).

3. Debugee
% java -agentlib:jdwp=transport=dt_socket,server=y,suspend=y,address=6666 -jar _____
% java -agentlib:jdwp=transport=dt_socket,server=y,suspend=y,address=6666 _____
1. server=y
Java application should be a TCP/IP server and wait for connections
2. suspend=y
The Java application (now server) will pause on start up and wait for
debugger to join. If ‘n‘, application will not wait for debugger at start up,
instead it will run as usual and when IDE encounters breakpoint it will
fork the application.
3. address=<debug-port>
A port number on which the debugger will join to debug the application.
Remember, this should be a port that is not already in use.

4. Debugger, Eclipse

6. Example Code
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class DebugRemote
{
public static void main(String args[]) throws InterruptedException
{
final JFrame frame = new JFrame("Remote Debug Demo");
JPanel panel = new JPanel();
final JButton btn = new JButton("On");
btn.setBackground(new Color(50, 200, 100));
frame.getContentPane().add(panel);
panel.add(btn);
frame.setVisible(true);
frame.pack();
btn.addActionListener(new ActionListener()
{

7. public void actionPerformed(ActionEvent arg0)
{
if ("On".equals(btn.getText()))
{
btn.setText("Off");
btn.setBackground(new Color(200, 50, 100));
}
else
{
btn.setText("On");
btn.setBackground(new Color(50, 200, 100));
}
}
});
}
}

8. Appendix

9. Eclipse - Console Option
1. Add following option before -vmargs in the eclipse.ini.
2. -console [port]
Enable the OSGi console.
-startup
...
-console
-vmargs
...

10. Eclipse - Verbose Option
1. Add following option after -vmargs in the eclipse.ini.
2. -verbose:class
Display information about each class loaded.
-vmargs
...
-verbose:class

11. Eclipse - Reference
1. Runtime Option
http://help.eclipse.org/indigo/index.jsp?topic=%2Forg.eclipse.platform.
doc.isv%2Freference%2Fmisc%2Fruntime-options.html