Possible Duplicate:
Java detect changes in filesystem
Can anyone suggest a Java API for tracking events in FileSystem? I found one - JNotify, but it doesn't support 64-bit systems.
Also, the new java.nio.* library is very new to use in a deployment level application, as many JREs don't really support it yet.
One alternative is to poll the FS for changes, which I am sure many do, but my gut feeling says that it's going to be very resource intensive.