com.bytelightning.opensource.pokerface

Class DirectoryWatchService

java.lang.Object

com.bytelightning.opensource.pokerface.DirectoryWatchService

public class DirectoryWatchService
extends Object

This class is a GOF Bridge pattern to decouple file watching from the underlying technology used to 'watch' a given directory for changes. Could use something like JNotify, but currently uses JDK 7.

Field Summary

Fields

Modifier and Type	Field and Description
protected Map<WatchKey,Path>	keys
protected Map<Path,DirectoryWatchEventListener>	listeners
protected WatchService	watcher

Constructor Summary

Constructors

Constructor and Description
DirectoryWatchService() Initialize the watching technology.

Method Summary

Modifier and Type	Method and Description
boolean	cancelWatch(Object token) Cancel a previously established watch
Object	establishWatch(Path watch, DirectoryWatchEventListener listener) Register a watch on the specified directory/file

Methods inherited from class java.lang.Object

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

Field Detail

watcher

protected final WatchService watcher

keys

protected final Map<WatchKey,Path> keys

listeners

protected final Map<Path,DirectoryWatchEventListener> listeners

Constructor Detail

DirectoryWatchService

public DirectoryWatchService()
                      throws IOException

Initialize the watching technology.

Throws:

IOException

Method Detail

establishWatch

public Object establishWatch(Path watch,
                             DirectoryWatchEventListener listener)
                      throws IOException

Register a watch on the specified directory/file

Returns:

An opaque token needed to cancel this 'watch'

Throws:

IOException

cancelWatch

public boolean cancelWatch(Object token)

Cancel a previously established watch

Parameters:

token - Value returned from establishWatch

Returns:

True if the watch existed and was successfully canceled.