org.drools.core.event

Class AbstractEventSupport<E extends EventListener>

java.lang.Object

org.drools.core.event.AbstractEventSupport<E>

All Implemented Interfaces:

Externalizable, Serializable

Direct Known Subclasses:

AgendaEventSupport, KieBaseEventSupport, KnowledgeAgentEventSupport, ProcessEventSupport, RuleEventListenerSupport, RuleRuntimeEventSupport

public abstract class AbstractEventSupport<E extends EventListener>
extends Object
implements Externalizable

Base class for Thread-safe Event Support in Drools. Note that subclasses wishing to access the listeners should do so via the getEventListenersIterator method. This will provide an Iterator accessing the current snapshot of the underlying list, freeing the subclasss of thread problems.

Please note that for lists of small sizes, and few modifications, the CopyOnWriteArrayList provides best performance. If the list is modified more often, than a simple ArrayList with synchonized operations, and copying of the array for iteration is faster.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
AbstractEventSupport()

Method Summary

Methods

Modifier and Type	Method and Description
void	addEventListener(E listener) Adds the specified listener to the list of listeners.
void	clear()
List<E>	getEventListeners()
protected Iterator<E>	getEventListenersIterator()
boolean	isEmpty()
void	readExternal(ObjectInput in)
void	removeEventListener(Class cls) Removes all event listeners of the specified class.
void	removeEventListener(E listener)
int	size()
void	writeExternal(ObjectOutput out)

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractEventSupport

public AbstractEventSupport()

Method Detail

readExternal

public void readExternal(ObjectInput in)
                  throws IOException,
                         ClassNotFoundException

Specified by:

readExternal in interface Externalizable

Throws:

IOException

ClassNotFoundException

writeExternal

public void writeExternal(ObjectOutput out)
                   throws IOException

Specified by:

writeExternal in interface Externalizable

Throws:

IOException

getEventListenersIterator

protected final Iterator<E> getEventListenersIterator()

addEventListener

public final void addEventListener(E listener)

Adds the specified listener to the list of listeners. Note that this method needs to be synchonized because it performs two independent operations on the underlying list

Parameters:

listener - to add

removeEventListener

public final void removeEventListener(Class cls)

Removes all event listeners of the specified class. Note that this method needs to be synchonized because it performs two independent operations on the underlying list

Parameters:

cls - class of listener to remove

removeEventListener

public final void removeEventListener(E listener)

getEventListeners

public List<E> getEventListeners()

size

public final int size()

isEmpty

public boolean isEmpty()

clear

public void clear()