Java comes with Slackware. It's on disk one.
I have it on my system to do some of my CS homework.
Code:
blt@lunchable:~$ java -version
java version "1.4.2_04"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2_04-b05)
Java HotSpot(TM) Client VM (build 1.4.2_04-b05, mixed mode)
Assuming you have the Slackware disk mounted at /mnt/iso then all you'll need to do is run the command
Code:
find /mnt/iso/ -name 'j2sdk*.tgz' -exec installpkg {} \;
Instant java goodness( ? ).