html contained in jar

From:
"johnmmcparland" <johnmmcparland@googlemail.com>
Newsgroups:
comp.lang.java.programmer
Date:
9 Oct 2006 01:55:02 -0700
Message-ID:
<1160384102.820305.286140@m73g2000cwd.googlegroups.com>
Hi all,

this seems like a commonly asked question, but so far I haven't found
an answer that works.

I wish to have a jar file which by containing a class which extends
JEditorPane and some html files, will display the html files which are
located inside the jar.

At the moment, I have a jar file with the following contents;

META-INF/
META-INF/MANIFEST.MF
help/
help/index.html
ui/
ui/Browser$HTMLBrowser$LinkListener.class
ui/Browser$HTMLBrowser.class
ui/Browser.class
ui/Browser.java

The Browser inner class HTMLBrowser extends JEditorPane to display html
(in this case help/index.html).

The code is below,

package ui;

import java.io.File;
import java.io.IOException;
import java.net.URL;

import javax.swing.JEditorPane;
import javax.swing.JFrame;
import javax.swing.event.HyperlinkEvent;
import javax.swing.event.HyperlinkListener;

public class Browser extends JFrame
{
    private HTMLBrowser browser;
    private static final long serialVersionUID= 1;

    public Browser()
    {
      setTitle("Help");
          browser= new HTMLBrowser();
          setContentPane(browser);
          setSize(800,600);
          setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
          setLocationRelativeTo(null);
          setVisible(true);
    }

    private class HTMLBrowser extends JEditorPane
    {
       private static final long serialVersionUID= 2;
       private static final String dir= "help";
       private static final String startPage= "index.html";

        public HTMLBrowser()
        {
         URL url;
         try
         {
         // Construct the URL
         // This is;
         // current dir + separator + help dir + separator + startPage
         String s= (new File(".")).getCanonicalPath();
         String separator= System.getProperty("file.separator");
         String t= s + separator + dir + separator + startPage;
                        // DEBUG
                        System.out.println(t);
         File f= new File(t);
         url= f.toURL();
         setPage(url);
         }
         catch (Exception e)
         {
            System.out.println( "Problem setting help homepage");
         }
           setEditable(false);
           addHyperlinkListener(new LinkListener(this));
       }

        private class LinkListener implements HyperlinkListener
        {
            private HTMLBrowser browser;

            public LinkListener(HTMLBrowser b)
            {
                browser= b;
            }

            public void hyperlinkUpdate(HyperlinkEvent he)
            {
                if (he.getEventType() == HyperlinkEvent.EventType.ACTIVATED)
                {
                    try
                                    {
                      URL newPage = he.getURL();
                     browser.setPage(newPage);

                                    }
                                    catch (IOException ioe)
                                    {
                        System.out.println( "Error opening new page");
                                    }
                    }
               }
        }

    }

    public static void main(String[] args)
    {
        new Browser();
    }

}

When I run this using "java Browser" (inside ui dir") it works (i.e.
displays the html page I want)
When I run the jar in the directory containing the "help" and "ui"
directories it works fine.
But when I run the jar anywhere else it does not work. The html page
is not displayed. Instead a blank JEditorPane is all that can be seen.

How can I get my class to look at the help/index.html file from within
the jar?

Thanks in advance,

John

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