sun's sdk? if you installed from rpm, then just go to /usr/java and see if a folder with the name of your sdk version is in there.
an easier way, which depends on if you have the path to java set, is to use the command, "java -version", from a shell terminal. you'll get output of the java version you're using.
if you didn't set the path and don't know how to set the path, just look at this - it's a partial copy of my /etc/profile file.
you want to copy these lines starting with "JAVA_HOME=" and paste them after the "#path manipulation" block ending with "fi". i'm really not sure though if placement really makes much difference though.
# Path manipulation
if [ `id -u` = 0 ]; then
pathmunge /usr/X11R6/bin after
pathmunge $JAVA_HOME/bin after