Jenkins CI broken on upgrade to Mac OS Mavericks

Putting this out there in case somebody has the same problem.  I upgraded my Jenkins box to OS X Mavericks, and Jenkins stopped responding; requests to localhost:8080 simply dropped.

After a bit of digging and dead ends, I found out that java wasn’t installed.  Running

javac -version

from the command line failed, and asked me to install Java.  I installed the lastest JDK, restarted jenkins with these commands:

sudo launchctl unload -w /Library/LaunchDaemons/org.jenkins-ci.plist
sudo launchctl load -w /Library/LaunchDaemons/org.jenkins-ci.plist

and everything seems to be back to normal.