Apple Computer released Java 1.3.1 and Java 1.4.2 Release 2 updates for Tiger Wednesday. The updates take the form of a single 45.3 megabyte download through Software Update, or through Appleis Support site.
The slightly more detailed release notes on the download page said that the update improves Java support in Tiger:
Java 2 Platform Standard Edition (J2SE) 1.3.1 and 1.4.2 Release 2 improves functionality of J2SE 1.4.2 on Mac OS X v. 10.4 Tiger and updates
J2SE 1.3.1 for better interaction with J2SE 1.4.2.
Release 2 includes Java 2 Platform Standard Edition versions 1.3.1_16 and 1.4.2_09.
You can find the update in Software Update on your Mac, or through the Support site. The download on the support site is listed as a 42MB download.