About Question enthuware.ocpjp.v7.2.1519 :

[fariz.siracli]

where can i read about WatchService and possible counts of events?

[admin]

http://docs.oracle.com/javase/7/docs/ap ... rvice.html

[admin]

https://docs.oracle.com/javase/tutorial ... ation.html

[sumanenthu]

What do you exactly try to mean by "The counts for ENTRY_CREATE and ENTRY_DELETE are exactly 1"? Does it mean that at a time we can have only one entry_create event queued?

[admin]

When you get a WatchEvent object, you can call its count() method to find out the number of times that event has occurred. However, if the event is for creation or deletion of a directory, then this method always returns 1.

Try playing with some sample code to understand this better: http://www.codejava.net/java-se/file-io ... ervice-api

[insider]

In explanation:
WatchKey register(WatchService watcher, WatchEvent.Kind<?>[] events) throws IOException

Second argument is actually a vararg, should be "WatchEvent.Kind<?>... events".
https://docs.oracle.com/javase/7/docs/a ... hable.html