Is there a way to detect file renaming using Java? (NIO's WatchService API or any other) From what I've seen when renaming a file two separate events occur - ENTRY_DELETE and then ENTRY_CREATE.
Take a look at jpathwatch. In addition to the standard watch event kinds specified in Java 7 (ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY) it also has additional events called ENTRY_RENAME_FROM and ENTRY_RENAME_TO which will fire when a file is renamed. Note that this depends on whether the underlying operating system supports file renaming events or not.