java are not reconize by firefox 3.6

This happens is because the correct symbolic link is missing from the folder /usr/lib/mozilla/plugins.
There should be a symbolic link named "libjavaplugin.so".
This usually points to another symbolic link named "moxilla-plugin.so" in the folder /etc/alternatives.
This symbolic link (mozilla-plugin.so) is then pointing to the java shared object "libnpjp2.so".
The shared object is in the folder "/usr/lib/jvm/java-6-sun/jre/lib/amd64".

A few corrections/additions to the message above.
1) The symbolic link in the folder "/etc/alternatives" is named "mozilla-javaplugin.so".
2) The folder "/usr/lib/jvm/java-6-sun" is a symbolic link to the actual java-sun folder like "/usr/lib/jvm/java-6-sun-1.6.0.16/"
     So actually the shared object "libnpjp2.so" is located in the folder "/usr/lib/jvm/java-6-sun-1.6.0.16/jre/lib/amd64".
3) There is also a symbolic link "libjavaplugin.so" in the folder "/usr/lib/xulrunner-addons/plugins" pointing to another symbolic link
     "xulrunner-javaplugin.so".

As a workaround to this bug (if the package sun-java6-plugin is installed) one should create two symbolic links:
1) /etc/alternatives/mozilla-javaplugin.so pointing to /usr/lib/jvm/java-6-sun/jre/lib/amd64/libnpjp2.so and
2) /usr/lib/mozilla/plugins/libjavaplugin.so pointing to /etc/alternatives/mozilla-javaplugin.so.

I have tested this with Lucid Lynx 64-bit with the browser firefox 3.6.1pre from the Mozilla daily build team PPA.
This makes java plugin actually be recognized and work OK.

Harry's solution worked for me. To make it easier, these are the commands that did the trick for me (use at your own risk!)

sudo rm /etc/alternatives/mozilla-javaplugin.so

sudo ln -s /usr/lib/jvm/java-6-sun/jre/lib/amd64/libnpjp2.so /etc/alternatives/mozilla-javaplugin.so

sudo rm /usr/lib/mozilla/plugins/libjavaplugin.so

sudo ln -s /etc/alternatives/mozilla-javaplugin.so /usr/lib/mozilla/plugins/libjavaplugin.so

well it don't work for me while it seem miss files:

:~$ sudo rm /etc/alternatives/mozilla-javaplugin.so

~$ sudo ln -s /usr/lib/jvm/java-6-sun/jre/lib/amd64/libnpjp2.so
:~$ /etc/alternatives/mozilla-javaplugin.so
bash: /etc/alternatives/mozilla-javaplugin.so: Aucun fichier ou dossier de ce type
~$ sudo rm /usr/lib/mozilla/plugins/libjavaplugin.so
~$ sudo ln -s /etc/alternatives/mozilla-javaplugin.so
~$ /usr/lib/mozilla/plugins/libjavaplugin.so
bash: /usr/lib/mozilla/plugins/libjavaplugin.so: Aucun fichier ou dossier de ce type

Starligths,
there are errors in your commands.
You actually broke commands into two pieces.

This is one command (put it in one line):

sudo ln -s /usr/lib/jvm/java-6-sun/jre/lib/amd64/libnpjp2.so /etc/alternatives/mozilla-javaplugin.so

And this one is also one command (to be put in one line):

sudo ln -s /etc/alternatives/mozilla-javaplugin.so /usr/lib/mozilla/plugins/libjavaplugin.so

Those commands will create the symbolic links needed. Better to copy-paste them in console.

Hi Harry,

Yes, i must open in new terminal while without it don't paste "sudo", now the both link exist but still java not working

Starslights,
you wrote you are using Karmic Kubuntu (9.10) with FF 3.6 but with java and icedtea.
You should only use sun-java6-jre and sun-java6-plugin but not OpenJDK and icedtea6-plugin.
Instructions I gave are only for sun-java.
Check also you have all symlinks I wrote in #3.

Hello Harry,

Thanks very much for your help, in fact it's the terminal who broke my command, i have all write my own and it worked.

If i copy paste , it broke the end of the command and put the symlink on the wrong places.

Have a great day and thanks for all again :D

Best Regards

Well another very interesting thing are that with your simlink, it fix a old bug i has who was impossible to open "java applet" with apparmor, now it's the first time on Karmic that it worked.

But still a few pages where i can't see live java script on it.

The same problem on lucid amd64.

Same problem in i386, harry's solution in #3 works for me.