http://obive.net/software/onkyoremote
This shows a menu in the menubar to control Onkyo and Integra receivers and preamplifiers.
OnkyoRemote depends on a few forked libraries:
https://github.com/idontusenumbers/jEISCP
And a library-not-yet-in-maven: https://github.com/blackears/svgSalamander
You'll need to grab a copy of all those dependencies and install them to your local maven
Then run mvn package
You should get a .app in the target
jpackage --input . --main-jar onkyoremote-1.1-jar-with-dependencies.jar
build_dmg.sh
Due to dependence on jEISCP, this code is under GPL v3 until further notice.