From christianherlambang at gmail.com  Fri May 11 22:01:08 2007
From: christianherlambang at gmail.com (Christian Herlambang)
Date: Fri, 11 May 2007 22:01:08 +0200
Subject: [imapping-dev] Mac Bug: How to and not produce the bug
Message-ID: <c996ed450705111301i617092d3i70ff338ea998541e@mail.gmail.com>

Hello iMap-devs,

1. Who am I?
I am a new working student in FZI. Heiko Haller is my advisor. My
first task is helping other iMapping-devs to solve the mac-bug.

2. Mac Bug: How to and not produce the bug
a. Problem:
imapping-pkm/src/main/java/org.ontoware.imapping.pkm/
PKMApplication.java

freezes after running a few seconds (the rainbow wheel of death)

b. Approach to find the bug
I replace the entire code in PKMApplication with a little JFrame
example (see my attachment) and try to make it run.

Result: it freezes.

Then, I stop the PKMApplication.java and configure the build path in
imapping-pkm. I remove all the required projects on the build path:
imapping-core, imapping-gui, imapping-libs

and run the PKMApplication.java

Result: the program doesn't freeze

3.Summary

I don't know if my founding is a help for the other imapping-devs. I
just want to let you know that the bug is caused by libraries that
PKMApplication import from.

Christian
-------------- next part --------------
package org.ontoware.imapping.pkm;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.*;

public final class PKMApplication {
	  private static JButton good = new JButton("Good");
	  private static JButton bad = new JButton("Bad");
	  private static JButton bad2 = new JButton("Bad2");
	  private static JLabel resultLabel = new JLabel("Ready", JLabel.CENTER);

	  public static void main(String[] args) {
	    JFrame f = new JFrame();
	    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

	    // Layout . . .
	    JPanel p = new JPanel();
	    p.setOpaque(true);
	    p.setLayout(new FlowLayout());
	    p.add(good);
	    p.add(bad);
	    p.add(bad2);
	    
	    Container c = f.getContentPane();
	    c.setLayout(new BorderLayout());
	    c.add(p, BorderLayout.CENTER);
	    c.add(resultLabel, BorderLayout.SOUTH);

	    // Listeners
	    good.addActionListener(new ActionListener() {
	      public void actionPerformed(ActionEvent ev) {
	        resultLabel.setText("Working . . .");
	        setEnabled(false);

	        // We're going to do something that takes a long time, so we
	        // spin off a thread and update the display when we're done.
	        Thread worker = new Thread() {
	          public void run() {
	            // Something that takes a long time . . . in real life, this
	            // might be a DB query, remote method invocation, etc.
	            try {
	              Thread.sleep(5000);
	            }
	            catch (InterruptedException ex) {}

	            // Report the result using invokeLater().
	            SwingUtilities.invokeLater(new Runnable() {
	              public void run() {
	                resultLabel.setText("Ready");
	                setEnabled(true);
	              }
	            });
	          }
	        };

	        worker.start(); // So we don't hold up the dispatch thread.
	      }
	    });

	    bad.addActionListener(new ActionListener() {
	      public void actionPerformed(ActionEvent ev) {
	        resultLabel.setText("Working . . .");
	        setEnabled(false);

	        // We're going to do the same thing, but not in a separate thread.
	        try {
	          Thread.sleep(5000); // Dispatch thread is starving!
	        }
	        catch (InterruptedException ex) {}

	        // Report the result.
	        resultLabel.setText("Ready");
	        setEnabled(true);
	      }
	    });

	    bad2.addActionListener(new ActionListener() {
	      public void actionPerformed(ActionEvent ev) {
	        resultLabel.setText("Working . . . ");
	        setEnabled(false);

	        // The wrong way to use invokeLater().  The runnable() shouldn't
	        // starve the dispatch thread.
	        SwingUtilities.invokeLater(new Runnable() {
	          public void run() {
	            try {
	              Thread.sleep(5000); // Dispatch thread is starving!
	            }
	            catch (InterruptedException ex) {}

	            resultLabel.setText("Ready");
	            setEnabled(true);
	          }
	        });
	      }
	    });

	    f.setSize(300, 100);
	    f.setVisible(true);
	  }

	  // Allows us to turn the buttons on or off while we work.
	  static void setEnabled(boolean b) {
	    good.setEnabled(b);
	    bad.setEnabled(b);
	    bad2.setEnabled(b);
	  }
}