I know nothing about Java but have used quite a few wiki's. It should be fairly simple to install a Perl or PHP based wiki on the Kindle.
A couple of Kindle projects already use tiny webservers such as BusyBox. Here' a link to how to run PHP with BusyBox
https://forum.openwrt.org/viewtopic.php?id=11098
I'd be tempted to use a wiki that needs no database (for speed and simplicity) eg DokuWiki
http://c2.com/cgi/wiki?WikiEngines
Good luck!