NoClassDefFound error when attempting to add an applet to my website

Question

I'm trying to add an applet with multiple jars to an HTML page but i get a NoClassDefFounderror: db.DAO when trying to run the program in my browser. DAO is a class on which TheaterApplet depends. My main JAR is theaterapplet.jar, it uses propproj.jar and firebirdsql-full.jar. i've use the following HTML code:

<APPLET         
CODE = "gui.TheaterApplet"          
WIDTH = "650"
HEIGHT = "650"
ARCHIVE = "propproj.jar,theaterapplet.jar,firebirdsql-full.jar"
>
</APPLET>

edited: this is the theaterapplet.jar output:

C:\Users\Roel>jar tvf theaterapplet.jar
    25 Mon Jan 06 17:49:48 CET 2014 META-INF/MANIFEST.MF
  1436 Mon Jul 29 17:41:04 CEST 2013 doc/allclasses-frame.html
  1256 Mon Jul 29 17:41:04 CEST 2013 doc/allclasses-noframe.html
  3486 Mon Jul 29 17:41:04 CEST 2013 doc/constant-values.html
 11598 Mon Feb 25 16:44:08 CET 2013 doc/db/BestellingDAO.html
  7251 Mon Jul 29 17:41:04 CEST 2013 doc/db/DAO.html
  9171 Mon Feb 25 16:44:08 CET 2013 doc/db/InterfaceBestellingDAO.html
  9613 Mon Feb 25 16:44:08 CET 2013 doc/db/InterfaceKlantDAO.html
  7439 Mon Jul 29 17:41:04 CEST 2013 doc/db/InterfacePlaatsDAO.html
  7116 Mon Jul 29 17:41:04 CEST 2013 doc/db/InterfaceTheaterDAO.html
  7397 Mon Jul 29 17:41:04 CEST 2013 doc/db/InterfaceVoorstellingDAO.html
 12203 Mon Feb 25 16:44:08 CET 2013 doc/db/KlantDAO.html
  9523 Mon Jul 29 17:41:04 CEST 2013 doc/db/PlaatsDAO.html
  9094 Mon Jul 29 17:41:04 CEST 2013 doc/db/TheaterDAO.html
  8914 Mon Jul 29 17:41:04 CEST 2013 doc/db/TheaterException.html
  9370 Mon Jul 29 17:41:04 CEST 2013 doc/db/VoorstellingDAO.html
  5532 Mon Feb 25 16:44:10 CET 2013 doc/db/class-use/BestellingDAO.html
  6047 Mon Jul 29 17:41:04 CEST 2013 doc/db/class-use/DAO.html
  5699 Mon Feb 25 16:44:10 CET 2013 doc/db/class-use/InterfaceBestellingDAO.html

  5613 Mon Feb 25 16:44:10 CET 2013 doc/db/class-use/InterfaceKlantDAO.html
  5650 Mon Jul 29 17:41:04 CEST 2013 doc/db/class-use/InterfacePlaatsDAO.html
  5666 Mon Jul 29 17:41:04 CEST 2013 doc/db/class-use/InterfaceTheaterDAO.html
  5795 Mon Jul 29 17:41:04 CEST 2013 doc/db/class-use/InterfaceVoorstellingDAO.h
tml
  5432 Mon Feb 25 16:44:08 CET 2013 doc/db/class-use/KlantDAO.html
  5464 Mon Jul 29 17:41:04 CEST 2013 doc/db/class-use/PlaatsDAO.html
  5484 Mon Jul 29 17:41:04 CEST 2013 doc/db/class-use/TheaterDAO.html
  8344 Mon Jul 29 17:41:04 CEST 2013 doc/db/class-use/TheaterException.html
  5584 Mon Jul 29 17:41:04 CEST 2013 doc/db/class-use/VoorstellingDAO.html
  1566 Mon Jul 29 17:41:04 CEST 2013 doc/db/package-frame.html
  6725 Mon Jul 29 17:41:04 CEST 2013 doc/db/package-summary.html
  5497 Mon Jul 29 17:41:04 CEST 2013 doc/db/package-tree.html
  6111 Mon Jul 29 17:41:04 CEST 2013 doc/db/package-use.html
  3436 Mon Jul 29 17:41:04 CEST 2013 doc/deprecated-list.html
  8780 Mon Jul 29 17:41:04 CEST 2013 doc/help-doc.html
  4900 Mon Jul 29 17:41:04 CEST 2013 doc/index-files/index-1.html
  4820 Mon Jul 29 17:41:04 CEST 2013 doc/index-files/index-10.html
  4591 Mon Jul 29 17:41:04 CEST 2013 doc/index-files/index-11.html
  5978 Mon Feb 25 16:44:10 CET 2013 doc/index-files/index-12.html
  5775 Mon Feb 25 16:44:10 CET 2013 doc/index-files/index-13.html
  5821 Mon Feb 25 16:44:10 CET 2013 doc/index-files/index-14.html
  4866 Mon Feb 25 16:44:10 CET 2013 doc/index-files/index-15.html
  4740 Mon Jul 29 17:41:04 CEST 2013 doc/index-files/index-2.html
  6185 Mon Jul 29 17:41:04 CEST 2013 doc/index-files/index-3.html
  4582 Mon Jul 29 17:41:04 CEST 2013 doc/index-files/index-4.html
  4929 Mon Jul 29 17:41:04 CEST 2013 doc/index-files/index-5.html
  4570 Mon Jul 29 17:41:04 CEST 2013 doc/index-files/index-6.html
  4590 Mon Jul 29 17:41:04 CEST 2013 doc/index-files/index-7.html
  4859 Mon Jul 29 17:41:04 CEST 2013 doc/index-files/index-8.html
  5493 Mon Jul 29 17:41:04 CEST 2013 doc/index-files/index-9.html
  1538 Mon Jul 29 17:41:04 CEST 2013 doc/index.html
   781 Mon Jul 29 17:41:04 CEST 2013 doc/overview-frame.html
  3956 Mon Jul 29 17:41:04 CEST 2013 doc/overview-summary.html
  5425 Mon Jul 29 17:41:04 CEST 2013 doc/overview-tree.html
    10 Mon Jul 29 17:41:04 CEST 2013 doc/package-list
  2313 Mon Feb 25 16:44:08 CET 2013 doc/resources/background.gif
   291 Mon Feb 25 16:44:08 CET 2013 doc/resources/tab.gif
 10701 Mon Feb 25 16:44:08 CET 2013 doc/resources/titlebar.gif
   849 Mon Feb 25 16:44:08 CET 2013 doc/resources/titlebar_end.gif
  3906 Mon Jul 29 17:41:04 CEST 2013 doc/serialized-form.html
 11613 Mon Feb 25 16:44:10 CET 2013 doc/stylesheet.css
 10216 Mon Jul 29 17:41:04 CEST 2013 doc/util/Util.html
  3825 Mon Jul 29 17:41:04 CEST 2013 doc/util/class-use/Util.html
   680 Mon Jul 29 17:41:04 CEST 2013 doc/util/package-frame.html
  4328 Mon Jul 29 17:41:04 CEST 2013 doc/util/package-summary.html
  4002 Mon Jul 29 17:41:04 CEST 2013 doc/util/package-tree.html
  3650 Mon Jul 29 17:41:04 CEST 2013 doc/util/package-use.html
   508 Mon Jul 29 19:42:16 CEST 2013 .project
   527 Mon Jan 06 16:10:52 CET 2014 .classpath
  1465 Mon Jan 06 16:10:52 CET 2014 db/DAO.class
  2383 Mon Jan 06 16:10:52 CET 2014 gui/TheaterApplet.class
  2500 Mon Jan 06 16:10:52 CET 2014 gui/WinkelwagenPanel.class
  3055 Mon Jan 06 16:10:52 CET 2014 gui/LoginPanel.class
  4775 Mon Jan 06 16:10:52 CET 2014 gui/ZaalPanel.class
  1461 Mon Jan 06 16:10:52 CET 2014 gui/VoorstellingPanel$UitvoeringListEvent.cl
ass
  1695 Mon Jan 06 16:10:52 CET 2014 gui/VoorstellingPanel$VoorstellingListEvent.
class
  4622 Mon Jan 06 16:10:52 CET 2014 gui/VoorstellingPanel.class
  1954 Mon Jan 06 16:10:52 CET 2014 model/Voorstelling.class
  1336 Mon Jan 06 17:44:06 CET 2014 model/Theater.class
  2540 Mon Jan 06 16:10:52 CET 2014 model/Uitvoering.class
   723 Mon Jan 06 16:10:52 CET 2014 model/Rang.class
  2969 Mon Jan 06 16:10:52 CET 2014 model/Controller.class
  1442 Mon Jan 06 16:10:52 CET 2014 model/Plaats.class

Anyone knows what's going wrong?

Answer 1

It's solved now. The applet still won't launch from my desktop computer but it launches from all other computers. Something is clearly going wrong locally. Maybe it's my browsers or maybe it has something to do with my security. All that matters is that it works now.

Answer 2

On the W3 Schools website http://www.w3schools.com/tags/tag_applet.asp in the example it has Bubbles.class. Have you tried using "gui.TheaterApplet.class" for the CODE tag?

The above does not work. Pointed out by Andrew Thompson.

If that doesn't work try using JarSplice to create a fat jar and then there will only be one jar and there might be less errors.

Have you tried using the <object> tag. What browser are you using it on. Your browser may not use the <applet> tags anymore. And also is TheaterApplet.class in the package with the exact name of gui? And I don't think this will change anything but have you tried changing, for example, CODE to code. Just a guess.