If you are running linux / unix without an X-server you have a problem. Depending on your java version you might be able to run you server with a -Djava.awt.headless=true vm switch.
So if you where running tomcat there should be a JAVA_OPTS is used for starting (and stopping tomcat) so with something like:
JAVA_OPTS="-Djava.awt.headless=true"
export JAVA_OPTS
You might be lucky.
Another option would be to install jai (java advanced imaging). I think from version 1.1.1 there should be no dependencies with X servers. If you do you will have to look at the jpeg encoder and how you load the fonts. Since my laptop has no more room for a double boot Linux I'm not inclined yet to look into this. If success full I'd be interested to hear...