I look at new functionnality for WatcherService.So I created a directory and I watch for events like files created or deleted or modify.I follow the example from http://blogs.oracle.com/thejavatutorials/entry/watching_a_directory_for_changes
I was surprised for an unexpected behaviour with WatcherService :
I make the following :
mkdir ~/tmp
touch ~/tmp/toto
Then I watched for events in ~/tmp/toto and it works fine.
Then I do the following :
mv ~/tmp ~/tmp.old
touch ~/tmp.old/titi
I look at events and there is events ! However I move the directory so the program should be throw an exception because of reset methods() but no !
So I post a message (It's the first time I post a message on the Oracle's web site !!!! ) and I wait for an answer ...
I will see if I post a good note ....
Here is the example source code form Oracle'sblog :
for (;;) {
//wait for key to be signaled
WatchKey key;
try {
key = watcher.take();
} catch (InterruptedException x) {
return;
}
for (WatchEvent event: key.pollEvents()) {
WatchEvent.Kind kind = event.kind();
//This key is registered only for ENTRY_CREATE events,
//but an OVERFLOW event can occur regardless if events are
//lost or discarded.
if (kind == OVERFLOW) {
continue;
}
//The filename is the context of the event.
WatchEvent ev = (WatchEvent)event;
Path filename = ev.context();
//Verify that the new file is a text file.
try {
//Resolve the filename against the directory.
//If the filename is "test" and the directory is "foo",
//the resolved name is "test/foo".
Path child = dir.resolve(filename);
if (!Files.probeContentType(child).equals("text/plain")) {
System.err.format("New file '%s' is not a plain text file.%n", filename);
continue;
}
} catch (IOException x) {
System.err.println(x);
continue;
}
//Email the file to the specified email alias.
System.out.format("Emailing file %s%n", filename);
//Details left to reader....
}
//Reset the key -- this step is critical if you want to receive
//further watch events. If the key is no longer valid, the directory
//is inaccessible so exit the loop.
boolean valid = key.reset();
if (!valid) {
break;
}
}
