Download JAR files tagged by listeners with all dependencies

Avalon Excalibur's resource management code allows you to be notified when a resource has changed. There are two methods of resource management: active and passive. Passive resource management acts as a holder for resources, and after the resource has been modified through it's normal API, notification goes to all listeners. Active resource management does the same, but it also polls the resources periodically to see if the resource was modified through an external method. Active resource management is perfect for monitoring files because they can be modified by external programs, and your program will be notified when the change occurs instead of constantly polling it.