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.
The resource management API uses regular JavaBeans property
change event handling.