First of all, here is my setup:
- Ubuntu 10.04
- Linux 2.6.32-32-generic #62-Ubuntu SMP Wed Apr 20 21:54:21 UTC 2011 i686 GNU/Linux
- Firefox 4
- Java 6
Issue: I am trying to use my linux machine to log into a java based remote office/terminal application for work. I'm pretty sure this used to work on Firefox 3/Ubuntu 9.04.
Currently, I have Firefox 4 installed and I was using the standard openJRE package that is installed with 10.04. When I would try to launch the applet, I would get an HTML window saying the applet was running but then nothing would happen.
I read these two questions:
- How do I get the Java plugin in Firefox 3.6 working?
- Firefox Hangs on ubuntu when loading java applets.
and tried switching to the official sun java 6 packages.
I then tried using the java.com tools to check if I had a working version of the java plugin. The window that is supposed to display the version details in a java applet seems to work but Firefox paints/locks up for about 30 seconds. If I click off of the window with the applet then click back, the applet box just displays junk/the desktop underneath the firefox window.
Any thoughts/suggestions/links that would help me: a. understand what is going on? b. help resolve the issue?
I checked syslog and poked around in /var/log but none of the timestamps on the logs updated when I was having the issue.
Thanks in advance.
I also ran the the below to check if the sun java was the only installed java and it appears that it is.
$ sudo update-java-alternatives -l java-6-sun 63 /usr/lib/jvm/java-6-sun
So the applet seems to work in Chromium which would lead me to believe this is a Firefox issue.
I also got the below error in the jconsole:
java.lang.ClassFormatError: Incompatible magic value 171731060 in class file hob/hltc/JHLTCap01 at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClassCond(ClassLoader.java:632) at java.lang.ClassLoader.defineClass(ClassLoader.java:616) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141) at sun.plugin2.applet.Applet2ClassLoader.findClass(Applet2ClassLoader.java:247) at sun.plugin2.applet.Plugin2ClassLoader.loadClass0(Plugin2ClassLoader.java:250) at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Plugin2ClassLoader.java:180) at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Plugin2ClassLoader.java:161) at java.lang.ClassLoader.loadClass(ClassLoader.java:248) at sun.plugin2.applet.Plugin2ClassLoader.loadCode(Plugin2ClassLoader.java:675) at sun.plugin2.applet.Plugin2Manager.createApplet(Plugin2Manager.java:3025) at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Plugin2Manager.java:1498) at java.lang.Thread.run(Thread.java:662) Exception: java.lang.ClassFormatError: Incompatible magic value 171731060 in class file hob/hltc/JHLTCap01
I tried clearing the cache and search for any jar files with the above in the name but again no luck.
Googling led me to this: http://stackoverflow.com/questions/2390733/incompatible-magic-value-1008813135
But not sure if that is the issue either.