If you want Java for ARM, your best bet is to download the Evaluation 
version from Oracle/SUN:

http://www.oracle.com/technetwork/java/javase/downloads/embedded-jsp-135769.html

The version for Slackware ARM is:

"Java SE for Embedded 6.0 Update 10 ARMv5 Linux (Build 42) - Headless, EABI, glibc 2.5, Soft Float, Little Endian"

The jre.SlackBuild script here builds a Slackware package of the 
binary distribution.