Lucid java-Contents available !
With 10.04 LTS released, I just generated the lucid java-Contents file !
As a reminder, java-Contents files help you locate a specific Java class in the distribution. It’s sometimes difficult to map a class to a JAR and then to the package that provides it. The lucid-java-Contents.gz file lists all classes in all JARs in all packages in Lucid, so now the answer you are looking for is just a zgrep away.
More information at: https://wiki.ubuntu.com/JavaTeam/JavaContents
java-Contents files are generated using code available at lp:~ttx/+junk/generate-java-Contents.