1) NIO2 Introduced new Mechanism to read a File.
Path
path=Paths.get ("F:\\niotestfiles\\one.txt");
2)The Watch Service API was introduced in Java 7 (NIO.2) as a thread-safe service that is capable of
watching objects for changes and events.
3)Watch Service API Classes
A)java.nio.file.WatchService interface
B)java.nio.file.Watchable interface
C)java.nio.file.StandardWatchEventKinds class
D)WatchEvent.Kind interface.
A)WatchService: It is the Starting Point of this API.
WatchService watchService = FileSystems.getDefault().newWatchService();
B)StandarWatchEventKinds:
a)StandardWatchEventKinds.ENTRY_CREATE:It is triggered when a file is renamed or moved into this directory.
b)StandardWatchEventKinds.ENTRY_DELETE:Renamed or moved.
c)StandardWatchEventKinds.ENTRY_MODIFY:Modified
d)StandardWatchEventKinds.OVERFLOW:Events might have been lost.
final Path path = Paths.get("C:/rafaelnadal");
WatchService watchService = FileSystems.getDefault().newWatchService();
path.register(watchService, StandardWatchEventKinds.ENTRY_CREATE,
StandardWatchEventKinds.ENTRY_MODIFY, StandardWatchEventKinds.ENTRY_DELETE);
watchService.close();
WatchService contains the below methods
poll():If No key is available it returns null value.
take():If no key is available,it waits until a key is queued.
1)Steps to Develop the watching API.
a)First Give the Path of Directory.
Path path=Paths.get("F:\\niotestfiles");
b)Watching service,
WatchService watchService=FileSystems.getDefault().newWatchService()
c)Register the path
path.register(watchService, StandardWatchEventKinds.ENTRY_CREATE,
StandardWatchEventKinds.ENTRY_MODIFY, StandardWatchEventKinds.ENTRY_DELETE);
d)Now start the infinite loop with while(true) or for(;;).
a)Key Watch
final WatchKey watchKey=watchService.take();
b)Poll Events.
watchKey.pollEvents()
c)What kind of events are done
final Kind kind=events.kind();
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