org.apache.openjpa.lib.util.concurrent
Class AbstractConcurrentEventManager

java.lang.Object
  org.apache.openjpa.lib.util.concurrent.AbstractConcurrentEventManager

All Implemented Interfaces:

Serializable, EventManager

Direct Known Subclasses:

AbstractDataCache, AbstractQueryCache, BrokerFactoryEventManager, JDBCEventConnectionDecorator, RemoteCommitEventManager, TransactionEventManager

public abstract class AbstractConcurrentEventManager
extends Object
implements EventManager, Serializable

Base event manager that handles adding/removing listeners and firing events. Meant for high concurrency. This class is reentrant-safe; listeners can be added and removed by other listeners when they receive events. The changes will not be visible until the event fire that initiated the recursive sequence of calls completes, however.

Author:

Abe White

See Also:

Serialized Form

Field Summary

protected Collection

_listeners

Constructor Summary

AbstractConcurrentEventManager()
Default constructor.

Method Summary

void	addListener(Object listener) Register an event listener.
Exception[]	fireEvent(Object event) Fire the given event to all listeners.
protected abstract void	fireEvent(Object event, Object listener) Implement this method to fire the given event to the given listener.
Collection	getListeners() Return a read-only list of listeners.
boolean	hasListener(Object listener) Return whether the given instance is in the list of listeners.
boolean	hasListeners() Return true if there are any registered listeners.
boolean	isFailFast() Whether to fail after the first exception thrown by any listener.
protected Collection	newListenerCollection() Return a new concurrent container for listeners.
boolean	removeListener(Object listener) Remove an event listener.
void	setFailFast(boolean failFast) Whether to fail after the first exception thrown by any listener.

Methods inherited from class java.lang.Object

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

Field Detail

_listeners

protected final Collection _listeners

Constructor Detail

AbstractConcurrentEventManager

public AbstractConcurrentEventManager()

Default constructor.

Method Detail

isFailFast

public boolean isFailFast()

Whether to fail after the first exception thrown by any listener.

setFailFast

public void setFailFast(boolean failFast)

Whether to fail after the first exception thrown by any listener.

addListener

public void addListener(Object listener)

Register an event listener.

Specified by:

addListener in interface EventManager

removeListener

public boolean removeListener(Object listener)

Remove an event listener.

Specified by:

removeListener in interface EventManager

hasListener

public boolean hasListener(Object listener)

Return whether the given instance is in the list of listeners.

Specified by:

hasListener in interface EventManager

hasListeners

public boolean hasListeners()

Return true if there are any registered listeners.

Specified by:

hasListeners in interface EventManager

getListeners

public Collection getListeners()

Return a read-only list of listeners.

Specified by:

getListeners in interface EventManager

fireEvent

public Exception[] fireEvent(Object event)

Fire the given event to all listeners.

Specified by:

fireEvent in interface EventManager

fireEvent

protected abstract void fireEvent(Object event,
                                  Object listener)
                           throws Exception

Implement this method to fire the given event to the given listener.

Throws:

Exception

newListenerCollection

protected Collection newListenerCollection()

Return a new concurrent container for listeners. Uses a CopyOnWriteArrayList by default.