The core module provides a java polling library which can be embedded in a java application which uses Logan Mcgrath's https://github.com/lmcgrath/app-config-app. See http://loganmcgrath.com/blog/2012/11/16/scm-backed-application-configuration-with-perforce/ for more background information.
The example-piano-webapp module shows an example of how the java poller can be used to detect configuration changes made in the app-config-app.
$ mvn install
Running the example piano webapp
First, run Logan Mcgrath's <https://github.com/lmcgrath/app-config-app>, then: $ cd example-piano-webapp $ mvn jetty:run
Then open http://localhost:8080/ to start playing with the piano. Make instrument changes in the app-config-app and observe that the piano switches to the new instrument.