name.pachler.nio.file
Class WatchService

java.lang.Object
  name.pachler.nio.file.WatchService

All Implemented Interfaces:

java.io.Closeable

public abstract class WatchService
extends java.lang.Object
implements java.io.Closeable

A service that provides monitoring for Watchables, reporting changes on these objects (in the case of jpathwatch, these are Path instances).

To utilise file monitoring, a program needs to acquire a watch service first, like this:
WatchService ws = FileSystems.getDefault().newWatchService();

A path needs to be constructed for the directory to be watched, by simply using the Paths class:
// assuming we want to watch the '/tmp' directory on a Unix system. Path path = Paths.get("/tmp");

We can now register the path with the watch service. In this case, we want to watch for files created under the /tmp directory, so we register using Path.register(name.pachler.nio.file.WatchService, name.pachler.nio.file.WatchEvent.Kind...) with the StandardWatchEventKind.ENTRY_CREATE event kind and no modifiers, like this:
WatchKey key = path.register(ws, ENTRY_CREATE);

Note that we receive a WatchKey now, which represents the registration of our path with the watch service. The key is also used subsequently to retreive events. We'll now wait for an event to occur, like this:
// this will block until an event has occurred, or the WatchService is closed. WatchKey k = ws.take();

Constructor Summary

protected

WatchService()

Method Summary

abstract void	close()
abstract WatchKey	poll()
abstract WatchKey	poll(long timeout, java.util.concurrent.TimeUnit unit)
abstract WatchKey	take()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

WatchService

protected WatchService()

Method Detail

close

public abstract void close()
                    throws java.io.IOException

Specified by:

close in interface java.io.Closeable

Throws:

java.io.IOException

poll

public abstract WatchKey poll()
                       throws java.lang.InterruptedException,
                              ClosedWatchServiceException

Throws:

java.lang.InterruptedException

ClosedWatchServiceException

poll

public abstract WatchKey poll(long timeout,
                              java.util.concurrent.TimeUnit unit)
                       throws java.lang.InterruptedException,
                              ClosedWatchServiceException

Throws:

java.lang.InterruptedException

ClosedWatchServiceException

take

public abstract WatchKey take()
                       throws java.lang.InterruptedException,
                              ClosedWatchServiceException

Throws:

java.lang.InterruptedException

ClosedWatchServiceException