Java has problems with Newer Linux systems that use IPV6. You need to set -Djava.net.preferIPv4Stack=true in your application to make things work.
I am sorry, but currently only JavaDoc is available. There will be more sophisticated documentation in future releases.
You can run Cups4J with Java 6. Type: java -jar cups4j.runnable.jar to get a help message to see what is possible right now. Just give it a try.
If you use Java 5, you also need JAXB 2.x and the STAX API on your classpath.
Currently I am not sure, what features I will implement next but I do hope to get some feedback of potential users to see what are the needs of other developers.
In my opinion it's e.g. not really necessary to be able to add or remove printers, as this can really easy be managed through the web interface of CUPS but someone might prove that black is white.
I do think about it. If there is enough feedback that people need this kind of stuff, sourceforge would be my first choice.
Any feedback can be sent to info at cups4j dot org. Alternatively you can leave a message in our forum.