Hello,
the message java.lang.NoClassDefFoundError means that your package
is probably incomplete. I assume that you have move splitter.jar to a different
directory without also copying the lib diroctory.
If that doesn't help, please download and unzip
http://www.mkgmap.org.uk/download/splitter-r427.zip
You should be able to execute the command in the directory
with splitter.jar
ciao,
Gerd