Questions on "Calling PC Commands from RPG" article

Note: IANAJPY (I Am Not A Java Programmer, Yet)

Has anyone perused "Calling PC Commands from RPG" by Kevin Vandever, found
at http://www.itjungle.com/mpo/mpo091202-story05.html ? (Try
http://tinyurl.com/dcahd )

I downloaded the java program, compiled it on my PC, and I have a .class
file that I have no idea what to do with. The goal is to have an RPG program
running on the iSeries submit a data queue entry containing the PC's IP
address and a PC command to run on that PC. Something running on the PC
accepts that data queue entry and runs the command.

Anybody know what actually runs on the PC? How to "invoke" (?) this? I
tried:
java CommandServerJDQ.class -cp "C:\Downloads\AS400\IBM Java\lib\jt400.jar"

... and got:
Exception in thread "main" java.lang.NoClassDefFoundError:
CommandServerJDQ/class

Note that the ClassPath (-cp) is the same used to compile the .java via the
javac command.

TIA, Dan