Apple today released Java for Mac OS X 10.5 Update 3 which delivers improvements to the security and compatibility of Java on Mac OS X 10.5.6 and later.
Java for Mac OS X 10.5 Update 3 is available via Software Update and also as standalone installers:
More info and download links: http://support.apple.com/downloads/
Further information regarding this update is available from this website: http://support.apple.com/kb/HT3374
For information on the security content of this update, visit: http://support.apple.com/kb/HT3437