Q23

An application is waiting for notification of changes to a tmp directory using the following code statements:

Path dir = Paths.get("tmp")

WatchKey key = dir.register (watcher, ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY) ;

In the tmp directory, the user renames the file testA to testB,

Which statement is true?

 

A.

The events received and the order of events are consistent across all platforms.

B.

The events received and the order of events are consistent across all Microsoft Windows versions.

 

C.

The events received and the order of events are consistent across all UNIX platforms.

D.

The events received and the order of events are platform dependent.

 

Risposta: A

Infatti se il file system ha un meccanismo di controllo per i cambiamenti nei file le API se ne avvantaggiano, altrimenti vanno in polling aspettando gli eventi.

Riferimento:

http://docs.oracle.com/javase/tutorial/essential/io/notification.html