The JDS includes the Java-realted RPMs

j2re
jmf-jre
j2re-integration

The files from these RPMs are loaded into a number of locations, including
/usr/java/j2re1.4.2_02

/usr/bin/java is set up by j2re-integration to point to

../java/j2redefault/bin/java

/usr/java/j2redefault is itself set up by j2re-integration.

When the Sun linux j2sdk rpm (j2sdk-1_4_2_03-linux-i586.rpm) is installed, it is loaded into /usr/java/j2sdk1.4.2_03/

The file /etc/profile.d/alljava.sh is intended to set up the shell variables necessary to run a number of Java applications; such variables as JAVA_HOME, JAVA_ROOT, JAVA_BINDIR and JRE_HOME, as well as making entries in PATH. As distributed (before loading the 1.4.2_03 RPM from Sun), these varaibles are not set. A glance at the contents of alljava.sh shows why: it is looking in the wrong places. Loading the 1.4.2_03 RPM makes no difference, of course.

alljava.sh includes the comment
# send feedback to ###@###.###

To be of any use to developers, these variables need to be set, so alljava.sh (and alljava.csh) need to be modified to relate to the Sun distributions.