Web Service Listener Configuration File

I was wondering if there's a way of getting a web service listener to refer to a configuration file (e.g. a *.properties file) which tells my web service which database etc. to communicate with, without having to hard-code this information into my custom web service listener class. When trying to re-use web services for different customers, I have to re-package a separate JAR for each customer, which is a bit tedious; it'd be better to have a one-size-fits-all listener, and simply change the path to the configuration file within Mirth Connect itself, rather than having to give every customer a different JAR for the same web service. Any ideas if this is possible, and how it could be achieved?

Web Service Listener Configuration File