After recently installing Knoppix on my new computer, I decided to start working on a programming project in Java started on my previous computer. I discovered that some of the code was not compiling correctly, possibly related to javac being gcj on my new system as opposed to the Sun java compiler on my old system. Anyway, I decided to try installing some new java tools.

Not really sure what I needed, I installed Synaptic to help my search. So far so good. I see the Jikes compiler, try it, don't get it to work, no biggie, move onto Eclipse. Here is where things get hairy. I try to install the complete Eclipse development kit/platform, whatever, about 6 pacakges in total. Something breaks along the way, although eclipse seems partially installed. I can run it sometimes, though it crashes easily and most times cannot start at all. I decide to say screw it and just uninstall both Jikes and all the Eclipse stuff.

I think I got some more apt-get errors on uninstall, though I can't remember for sure. My Java VM still seems to run okay, although now it gives the error:

Mar 22, 2004 11:11:16 PM java.util.prefs.FileSystemPreferences$3 run
WARNING: Could not create system preferences directory. System preferences are unusable.

when I run something, which it did not before. I would like to know what is happening here and how I can clean it up.

The biggest problem though is that Mozilla no longer recognizes the Java plugin! Everything looks correct, although the symlinks seem a bit convoluted they all point to the correct places: /usr/lib/mozilla/plugins/javaplugin_oji.so --> /etc/alternatives/javaplugin_oji.so --> /usr/lib/j2se/1.4/jre/i386/mozilla/javaplugin_oji.so. In that final target the mozilla directory is itself a symlink to same level directory ns610-gcc32. Everything appears to be just as it should but mozilla shows no java plugin under About -> Plugins, and tells me I need to install a plugin when I try to run applets. This is after multiple Mozilla restarts and a system reboot.

Getting my Java VM and plugin back in working order is my top priority. After that, and advice related to getting a solid, Java 1.4 development environment setup would be greatly appreciated. Currently I have gcj-3.3 as my java compiler and j2re1.4 (Blackdown 1.4.0.99beta-1) as VM. Both of these were included in the original Knoppix install and AFAIK have not been modified but the other installations I've tried.

Thanks.