Hi Thorsten, tony, all, many thanks for your help! It almost started working now: I added a wrapper script as suggested by tony and got rid of the missing class definitions. However, the next challenge turned up: filius uses some 'resources' [1] which need to be available and I am not sure how to solve this best. So far, they are not deployed by the packet automatically, but a debian/libfilius-java.install file solves this.
The 'resources' are expected relative to /usr/share/java/filius.jar in directories (i.e. config/filius.ini). How is it best to handle this situation? Is it possible to tweak the path somehow (in the wrapper script?) or do I need to patch the sources? Right now, I copy the resources to /usr/share/filius/. Many thanks in advance for help and hints, Andi [1] https://gitlab.com/filius1/filius/-/tree/master/src/main