A ready to go distribution of Project Zomboid multiplayer (41.60) shipped as a Docker container.
I had to create a project-zomboid.jar
file by running jar cvf project-zomboid.jar ./**/*.class
from the installation directory of zomboid.
I then had to install that jar into my local maven repository with the following command:
mvn install:install-file -Dfile=./project-zomboid.jar -DgroupId=zombie -DartifactId=zombie -Dversion=1.0.0 -Dpackaging=jar -DgeneratePom=true