org.sourceforge.jemm.client.id
Class TrackedIDFactoryImpl

java.lang.Object
  org.sourceforge.jemm.client.shared.WeakSingletonFactory<ID,TrackedID>
      org.sourceforge.jemm.client.id.TrackedIDFactoryImpl

All Implemented Interfaces:

TrackedIDFactory

public class TrackedIDFactoryImpl
extends WeakSingletonFactory<ID,TrackedID>
implements TrackedIDFactory

A Factory which creates a Flyweight of TrackedIDs such that two different ID objects, new ID(1) and new ID(1) will both map to the same TrackedID(1) object. This is flyweight like pattern is used to allow reliable tracking of IDs on the client side such that when an ID is no longer being used the server can be told that this client is no longer holding a reference to an object with that ID or the ID itself for some purpose. It is important that TrackedID's never get created any other way than via this Factory, and that normal ID instances do not get into the ShadowObject. This class is thread safe.

Author:

Paul Keeble

Field Summary

protected java.util.Set<TrackedIDListener>

listeners

Fields inherited from class org.sourceforge.jemm.client.shared.WeakSingletonFactory

keysToWeakRefs, queue, queueListener, refsToKeys

Constructor Summary

TrackedIDFactoryImpl()
Creates a new Factory with no ids mapped

Method Summary

void	addListener(TrackedIDListener listener) Adds a listener which receives notification if a trackedID is enqueued for garbage collection.
protected TrackedID	createValue(ID id)
protected void	notifyExpired(ID id)
void	removeListener(TrackedIDListener listener) Removes the listener

Methods inherited from class org.sourceforge.jemm.client.shared.WeakSingletonFactory

contains, create, get, put, remove, shutdown, size

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.sourceforge.jemm.client.id.TrackedIDFactory

contains, create, get, remove

Field Detail

listeners

protected final java.util.Set<TrackedIDListener> listeners

Constructor Detail

TrackedIDFactoryImpl

public TrackedIDFactoryImpl()

Creates a new Factory with no ids mapped

Method Detail

notifyExpired

protected void notifyExpired(ID id)

Specified by:

notifyExpired in class WeakSingletonFactory<ID,TrackedID>

addListener

public void addListener(TrackedIDListener listener)

Description copied from interface: TrackedIDFactory

Adds a listener which receives notification if a trackedID is enqueued for garbage collection.

Specified by:

addListener in interface TrackedIDFactory

removeListener

public void removeListener(TrackedIDListener listener)

Description copied from interface: TrackedIDFactory

Removes the listener

Specified by:

removeListener in interface TrackedIDFactory

createValue

protected TrackedID createValue(ID id)

Specified by:

createValue in class WeakSingletonFactory<ID,TrackedID>