Package org.dellroad.stuff.pobj

Class PersistentObjectEvent<T>

java.lang.Object

java.util.EventObject

org.dellroad.stuff.pobj.PersistentObjectEvent<T>

Type Parameters:

T - type of the root persistent object

All Implemented Interfaces:

Serializable

public class PersistentObjectEvent<T>
extends EventObject

Notification event emitted by a PersistentObject to listeners whenever there is an update to the root object.

See Also:

• Serialized Form

Field Summary

Fields inherited from class java.util.EventObject

source

Constructor Summary

Constructors

Constructor	Description
PersistentObjectEvent(PersistentObject<T> persistentObject, long version, T oldRoot, T newRoot)	Constructor.

Method Summary

Modifier and Type	Method	Description
T	getNewRoot()	Get the new root after the update.
T	getOldRoot()	Get the old root prior to the update.
PersistentObject<T>	getSource()	Get the PersistentObject that originated this event.
long	getVersion()	Get the version that this event is associated with.

Methods inherited from class java.util.EventObject

toString

Methods inherited from class java.lang.Object

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

Constructor Details

PersistentObjectEvent

public PersistentObjectEvent(PersistentObject<T> persistentObject,
 long version,
 T oldRoot,
 T newRoot)

Constructor.

Parameters:

persistentObject - source of this event

version - the new persistent object version (i.e., the version of newRoot)

oldRoot - previous root object; null if exiting from an empty start period

newRoot - updated root object; null if entering an empty stop period

Method Details

getSource

public PersistentObject<T> getSource()

Get the PersistentObject that originated this event.

Overrides:

getSource in class EventObject

getVersion

public long getVersion()

Get the version that this event is associated with. This will be the version of the new root.

The PersistentObject class always delivers notifications in order, so this number should always increase over time.

Returns:

new root version number

getOldRoot

public T getOldRoot()

Get the old root prior to the update.

The caller must not modify the returned object, as it is shared among all listeners.

Returns:

the old root object; will be null if an empty start period has just ended

getNewRoot

public T getNewRoot()

Get the new root after the update.

The caller must not modify the returned object, as it is shared among all listeners.

Returns:

the new root object; will be null if an empty stop period has just started