I need to build a Java app to run like a daemon on UNIX (FreeBSD). The app would need to start up just like any UNIX process. After starting, it sits there and wait for commands from the master host/server. Commands are fed to this app via RESTful web services calls - so it needs to listen for network connections at a particular port. At the same time, it needs to access resouces at external hosts/websites by making outgoing http calls.
What is the best approach for writing such app? I am thinking of writing a standalone app and include Grizzly and Jersey libraries. Is this the right approach? Is there a better approach?
(Also, I don't think I should write a normal web application - war file - to be deployed in GlassFish or some sort of Java container.)