Since the End of Life of Sun's Java 5 is reached and even the End of Service Life (EOSL) at 8th of October 2009 already passed the Ubuntu developers removed Sun's Java 5 from Karmic (Bug 418577).
Unfortunately I still need Java 5 and it would be quite some effort to port the projects to Sun's Java 6, especially the QA and customer roll-out would be terribly intricate. Somebody on ubuntuforums.org posted the idea to port the Jaunty release.
That's what I did now. Downloaded the Jaunty source packages and build new ones on my Karmic box.
This works perfectly fine for me and I'll try to put the files in a repository soon in case anybody else is in the same position.
1.5.0-22 on Karmic
I'm in the same spot as you, stuck needing the 1.5 JDK. Unfortunately I hadn't seen that it was unsupported by Karmic when I hit upgrade yesterday. I am now attempting build the JDK from the source. Could you give a step-by-step guide to building it?
I simply use the Jaunty
I simply use the Jaunty version which is 1.5.0-19 and re-compiled for Karmic.
http://archive.ubuntu.com/ubuntu/pool/multiverse/s/sun-java5/sun-java5_1...
http://archive.ubuntu.com/ubuntu/pool/multiverse/s/sun-java5/sun-java5_1...
http://archive.ubuntu.com/ubuntu/pool/multiverse/s/sun-java5/sun-java5_1...
The short version is somehow like this:
In case you get dependency errors, just repeat the last step again.
However I'll try to post an detailed guide the next days.
HTH