Hello, yeah I had a similar problem with java which took me a little time to sort out, first of all you need to link in Java Virtual Machine under your bash profile file, you will need to find where you have installed a suitable Java Run Time environment, for me it is located in the following directory /usr/java/jdk1.5.0_01/jre, but this will variey depending on your installation prefernce. Right now for the reference in the .bash_profile file, open a terminal make sure you are in you home directory, if you are not type in
cd ~
This has the effect of navigating the terminal to your home directory
next you will need to open the .bash_profile file (note to insert text use i)
vi .bash_profile
you will see something which looks like this with any luck
PATH=$PATH:$HOME/bin
amend it so it looks something like this (adjusting for your virtual machine location and adding bin onto the end) note that the delimiter between new ones is a : not a ;
PATH=$PATH:$HOME/bin:/usr/java/jdk1.5.0_01/jre/bin
also if you are using a java development kit you should define the following
JAVA_HOME=/usr/java/jdk1.5.0_01/
export JAVA_HOME
save the document by pressing the Escape key and typing :wq followed by a carriage return
open another terminal, this is where you will check to see if you changes have taken effect type the following and execute
echo $PATH
this should show the updated PATH, you can now continue to install java enabled applications. Note you might have to restart for the changes to take effect.
For Firefox you have to create a link to the java runtime environment plugin. This is located in the JRE directory normally in a directory called plugin/i386/ns7
You will need to locate where the firefox directory is by going to be, mine is /usr/lib/firefox-1.0, from there you will need to go into the plgins directory and make a link, please not you will need to be either logged in as root, or have used the su command to create the link I typed in the following to create the link.
ln -s /usr/java/jdk1.5.0_01/jre/plugin/i386/ns7/libjavaplugin-oji.so
The firefox java issue is addressed in the FAQ section
http://www.mozilla.org/support/firefox/faq#q2.2 please note the answer didn't quite work for me as it linked a file which made my browser crash all the time, thats why I have adjusted the link location.
I hope this works out for you I know how frustrating it is to get java going.