I've successfully installed Java from the Medibuntu repo. Based upon prior experience, I selected the sdk version. In order for it to run in Firefox, you will need to build the symbolic link as set out in the Wiki page. For those interested, here's what I did, with success:
In a terminal:
Code:
mkdir -p ~/.mozilla/plugins
cd ~/.mozilla/plugins
ln -s /usr/lib/j2sdk1.5-ibm/jre/bin/libjavaplugin_oij.so