Question

Error loading class: HelloWorld
java.lang.NoClassDefFoundError
java.lang.ClassNotFoundException: HelloWorld
   at com/ms/vm/loader/URLClassLoader.loadClass (URLClassLoader.java)
   at com/ms/vm/loader/URLClassLoader.loadClass (URLClassLoader.java)
   at com/ms/applet/AppletPanel.securedClassLoad (AppletPanel.java)
   at com/ms/applet/AppletPanel.processSentEvent (AppletPanel.java)
   at com/ms/applet/AppletPanel.processSentEvent (AppletPanel.java)
   at com/ms/applet/AppletPanel.run (AppletPanel.java)
   at java/lang/Thread.run (Thread.java)

from http://www.kndrdsystms.com/twiki/bin/view/Sandbox/WhatDoYouThink

Same applet works from http://www.kndrdsystms.com/Hello.html

Tried many iterations of the applet = "location". Tried many iterations of SetEnv CLASSPATH path in httpd.conf (shows in testenv)

Searched all of twiki.org for java applet issues. Expected at least "You can't do java applets" or "Do this to run java applets" - no joy.

A little push in the right direction would be most kind and helpful.

• TWiki version: 01 Feb 2003
• Perl version: 5.6.1
• Web server & version: Apache/1.3.26 (Unix) Debian GNU/Linux mod_perl 1.26
• Server OS: Linux 2.4.18-686 (Debian)
• Web browser & version: various
• Client OS: various

-- KennethArnold - 15 Jul 2003

Answer

The TWikiDrawPlugin is a Java applet that's embedded into TWiki pages. It might give you a hint about how to do the same. Although ... that plugin is a plugin rather than an attachment to your currect page/topic, so maybe the path problem you see does not appear.

-- TorbenGB - 16 Jul 2003

I looked at TWikiDrawPlugin and its earlier incarnations. (Nice app BTW.) This is certainly the way to go to add to the functionality of TWiki in general and individual sites in particular. My aim is to be able to demonstrate concepts, algorithms, development ideas, etc. with short code snippets/examples inline so to speak with something less trivial than javascript (which is also more likely to be blocked or disabled).

-- KennethArnold - 16 Jul 2003

DOH! It's an HTML thing -

codebase = codebaseURL 
   This optional attribute specifies the base URL of the applet -- the directory or folder that
   contains the applet's code. If this attribute is not specified, then the document's URL is used. 

-- KennethArnold - 16 Jul 2003