Yesterday ( 25.04.2008 ) was the day of the intellectual property.

But does software fall into this category?

In my opinion you cannot grant patents to ideas – only e.g. to devices. I think you cannot grant a patent like ‘enter the code for the sales discount’. You can only put a copyright on the code (e.g. which queries the database), but copyright means that others cannot (easily) make a duplicate – it doesn’t mean that others cannot ‘use’ this idea (plagiates are forbidden of course). If the granted patents on software can be executed in europe, then many open source programmer – like me – gets a lot of trouble!

Today I discovered a good (english or german) example at ffii.de to demonstrate which patents could be violated if you develop a simple webshop. It was really impressive for me that these patents are actually granted.

To look for the mentioned patent numbers you can use espacenet.com.

Nearly all projects need to log something. You can use System.out.println(String) for that. But if you want to write the message to a file later you have to change all the logging statements in your code.

So it is recommended to use at least the Logger provided by the jdk:

java.util.logging.Logger

Other projects for logging exist e.g. the popular log4j. But this library is complex and the jar file is too big for my purposes.

Today I discovered slf4j, which is small (<25KB) and provides wrappers for the jdk-Logger and log4j. The nice thing about this library is that you can simply put the jar files into the classpath and slf4j will use e.g. the jdk-Logger. I like it more than the jdk-Logger because slf4j offers a nice interface for logging (the methods are easier to use) e.g.:

• info(String)
• info(String, Throwable)
• warn(String)
• warn(String, Throwable)
• error(String)
• error(String, Throwable)

But all logger don’t have a feature to log directly to the user. So I implemented a Handler that prints a JDialog with the message and the full stack trace. The stack trace will be available if the user clicks on the details button.

/*
 * This file is part of the timefinder project.
 * Visit http://www.timefinder.de for more information.
 * Copyright (C) 2008 Peter Karich.
 *
 * This project is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; version 2.1 of the License.
 *
 * This project is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this project; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 * or look at http://www.gnu.org
 */
package de.timefinder.framework;

import java.awt.BorderLayout;
import java.util.logging.Handler;
import java.util.logging.Level;
import java.util.logging.LogRecord;
import javax.swing.Icon;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;

/**
 * This class provides a Log Handler to be publish directly to the user via
 * a JDialog, which offers a details Button.
 * 
 * @author Peter Karich, peat_hal ‘at’ users ‘dot’ sourceforge ‘dot’ net
 */
public class SwingHandler extends Handler {

    @Override
    public void publish(LogRecord record) {
        if (!isLoggable(record)) {
            return;
        }
        int level = record.getLevel().intValue();
        int jOptLevel;

        if (level >= Level.SEVERE.intValue()) {
            jOptLevel = JOptionPane.ERROR_MESSAGE;
        } else if (level >= Level.WARNING.intValue()) {
            jOptLevel = JOptionPane.WARNING_MESSAGE;
        } else {
            jOptLevel = JOptionPane.INFORMATION_MESSAGE;
        }

        logIntoDialog(jOptLevel, record.getMessage(), record.getThrown());
    }

    @Override
    public void flush() {
    }

    @Override
    public void close() throws SecurityException {
    }

    private static void logIntoDialog(final int messageLevel,
            final String errorMessage,
            final Throwable th) {

        if (!SwingUtilities.isEventDispatchThread()) {
            try {
                SwingUtilities.invokeAndWait(new Runnable() {

                    public void run() {
                        logIntoDialog(messageLevel, errorMessage, th);
                    }
                });
            } catch (Exception ex) {
                JOptionPane.showConfirmDialog(null, errorMessage);
            }

            return;
        }

        StringBuilder sb = new StringBuilder();
        sb.append(errorMessage);
        if (errorMessage == null || errorMessage.length() == 0) {
            if (th != null) {
                sb.append(th.getClass().getName());
                sb.append(": ");
            }
            // TODO I18N
            sb.append("Error-Message Not Available>");
        }

        String newErrMessage = sb.toString();
        if (th != null) {
            TFFormatter.printReason(sb, th);
        }

        JScrollPane scroll = new JScrollPane(new JTextArea(sb.toString(), 20, 40));
        JPanel panel = new JPanel(new BorderLayout());
        panel.add(new JTextField(newErrMessage), BorderLayout.CENTER);
        panel.add(scroll, BorderLayout.SOUTH);
        // TODO I18N
        Object[] options = {"Okay", "Details"};
        int n = JOptionPane.NO_OPTION;
        Icon icon;

        switch (messageLevel) {
            case JOptionPane.WARNING_MESSAGE:
                icon = UIManager.getIcon("OptionPane.warningIcon");//NO I18N
                break;
            case JOptionPane.ERROR_MESSAGE:
                icon = UIManager.getIcon("OptionPane.errorIcon");//NO I18N
                break;
            case JOptionPane.INFORMATION_MESSAGE:
                icon = UIManager.getIcon("OptionPane.informationIcon");//NO I18N
                break;
            default:
                icon = UIManager.getIcon("OptionPane.questionIcon");//NO I18N
        }

        boolean visible = false;
        //Switch between Details and No-Details:
        while (n != JOptionPane.YES_OPTION) {
            scroll.setVisible(visible);
            panel.revalidate();

            n = JOptionPane.showOptionDialog(
                    null,
                    panel,
                    newErrMessage,
                    JOptionPane.YES_NO_OPTION,
                    messageLevel,
                    icon,
                    options,
                    options[0]);

            visible = !visible;
        }
    }
}