Package org.elasticsearch.watcher

Class AbstractResourceWatcher<Listener>

java.lang.Object

org.elasticsearch.watcher.AbstractResourceWatcher<Listener>

All Implemented Interfaces:

ResourceWatcher

Direct Known Subclasses:

FileWatcher

public abstract class AbstractResourceWatcher<Listener>
extends Object
implements ResourceWatcher

Abstract resource watcher framework, which handles adding and removing listeners and calling resource observer.

Constructor Summary

Constructors

Constructor	Description
AbstractResourceWatcher()

Method Summary

Modifier and Type	Method	Description
void	addListener(Listener listener)	Registers new listener
void	checkAndNotify()	Called periodically by ResourceWatcherService so resource watcher can check the resource
protected abstract void	doCheckAndNotify()	Will be called periodically
protected abstract void	doInit()	Will be called once on initialization
void	init()	Called once when the resource watcher is added to ResourceWatcherService
protected List<Listener>	listeners()	Returns a list of listeners
void	remove(Listener listener)	Unregisters a listener

Methods inherited from class java.lang.Object

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

Constructor Details

AbstractResourceWatcher

public AbstractResourceWatcher()

Method Details

init

public void init()
          throws IOException

Description copied from interface: ResourceWatcher

Called once when the resource watcher is added to ResourceWatcherService

Specified by:

init in interface ResourceWatcher

Throws:

IOException

checkAndNotify

public void checkAndNotify()
                    throws IOException

Description copied from interface: ResourceWatcher

Called periodically by ResourceWatcherService so resource watcher can check the resource

Specified by:

checkAndNotify in interface ResourceWatcher

Throws:

IOException

addListener

public void addListener(Listener listener)

Registers new listener

remove

public void remove(Listener listener)

Unregisters a listener

listeners

protected List<Listener> listeners()

Returns a list of listeners

doInit

protected abstract void doInit()
                        throws IOException

Will be called once on initialization

Throws:

IOException

doCheckAndNotify

protected abstract void doCheckAndNotify()
                                  throws IOException

Will be called periodically

Implementing watcher should check resource and notify all listeners().

Throws:

IOException