org.exolab.jms.messagemgr
Class QueueDestinationCache

java.lang.Object
  org.exolab.jms.messagemgr.DestinationCache
      org.exolab.jms.messagemgr.QueueDestinationCache

All Implemented Interfaces:

java.io.Serializable, GarbageCollectable, Identifiable, LeaseEventListenerIfc, MessageManagerEventListener

public class QueueDestinationCache
extends DestinationCache

A DestinationCache for Queues

Version:

$Revision: 1.34.2.1 $ $Date: 2004/05/01 12:05:26 $

Author:

Jim Alateras

See Also:

Serialized Form

Field Summary

protected java.util.List

_queueListeners Maintains a list of queue listeners for this cache

Fields inherited from class org.exolab.jms.messagemgr.DestinationCache

_consumers, _leaseHelper

Method Summary

void	addQueueListener(QueueListener listener) A Queue can also hav a queue listener, which simply gets informed of all messages that arrive at this destination
boolean	canDestroy() Determines if this cache can be destroyed.
JmsDestination	getDestination() Return a reference to the underlying destination
MessageHandle	getMessage(QueueConsumerEndpoint endpoint) Return the first message of the queue or null if there are no messages in the cache
int	hashCode()
boolean	messageAdded(JmsDestination destination, MessageImpl message) This method is called when the MessageMgr adds a message for this destination to the cache
void	messageRemoved(JmsDestination destination, MessageImpl message) This method is called when the MessageMgr removes a message from the cache.
boolean	persistentMessageAdded(java.sql.Connection connection, JmsDestination destination, MessageImpl message) This event is called when the MessageMgr adds a persistent message to the cache.
void	persistentMessageRemoved(java.sql.Connection connection, JmsDestination destination, MessageImpl message) This event is called when the MessageMgr removes a persistent message from the cache.
void	playbackMessages(QueueListener listener) Playback all the messages in the cache to the specified QueueListener
void	removeQueueListener(QueueListener listener) Remove the queue listener associated with this cache
void	returnMessage(MessageHandle handle) Return the specified message to top of the queue.
java.lang.String	toString()

Methods inherited from class org.exolab.jms.messagemgr.DestinationCache

collectGarbage, getConsumers, getDestinationByName, getId, getMaximumSize, getMessageCount, onLeaseExpired, registerConsumer, resolveExpiredMessage, setCacheEvictionPolicy, setMaximumSize, shutdown, unregisterConsumer

Methods inherited from class java.lang.Object

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

Field Detail

_queueListeners

protected java.util.List _queueListeners

Maintains a list of queue listeners for this cache

Method Detail

getDestination

public JmsDestination getDestination()

Description copied from class: DestinationCache

Return a reference to the underlying destination

Specified by:

getDestination in class DestinationCache

Returns:

JmsDestination

addQueueListener

public void addQueueListener(QueueListener listener)

A Queue can also hav a queue listener, which simply gets informed of all messages that arrive at this destination

Parameters:

listener - - queue listener

removeQueueListener

public void removeQueueListener(QueueListener listener)

Remove the queue listener associated with this cache

Parameters:

listener - - queue listener to remove

messageAdded

public boolean messageAdded(JmsDestination destination,
                            MessageImpl message)

Description copied from class: DestinationCache

This method is called when the MessageMgr adds a message for this destination to the cache

Specified by:

messageAdded in interface MessageManagerEventListener

Specified by:

messageAdded in class DestinationCache

Parameters:

destination - the message's destination

message - - message added to cache

Returns:

true if this message was accepted

messageRemoved

public void messageRemoved(JmsDestination destination,
                           MessageImpl message)

This method is called when the MessageMgr removes a message from the cache.

Specified by:

messageRemoved in interface MessageManagerEventListener

Specified by:

messageRemoved in class DestinationCache

Parameters:

destination - the message destination

message - the message removed from cache

persistentMessageAdded

public boolean persistentMessageAdded(java.sql.Connection connection,
                                      JmsDestination destination,
                                      MessageImpl message)
                               throws PersistenceException

Description copied from interface: MessageManagerEventListener

This event is called when the MessageMgr adds a persistent message to the cache.

Parameters:

connection - the database connection

destination - the message's destination

message - message added to cache

Returns:

trueThrows:

PersistenceException - if there is a persistence related problem

persistentMessageRemoved

public void persistentMessageRemoved(java.sql.Connection connection,
                                     JmsDestination destination,
                                     MessageImpl message)
                              throws PersistenceException

Description copied from interface: MessageManagerEventListener

This event is called when the MessageMgr removes a persistent message from the cache.

Parameters:

connection - the database connection

destination - the message's destination

message - message to remove from cache

Throws:

PersistenceException - - if there is a persistence related problem

getMessage

public MessageHandle getMessage(QueueConsumerEndpoint endpoint)

Return the first message of the queue or null if there are no messages in the cache

Parameters:

QueueConsumerEndpoint - - the consumer who will receive the message

Returns:

MessageHandle - handle to the first message

playbackMessages

public void playbackMessages(QueueListener listener)

Playback all the messages in the cache to the specified QueueListener

Parameters:

listener - - the queue listener

returnMessage

public void returnMessage(MessageHandle handle)

Return the specified message to top of the queue. This is called to recover unsent or unacked messages

Parameters:

message - - message to return

canDestroy

public boolean canDestroy()

Determines if this cache can be destroyed. A QueueDestinationCache can be destroyed if there are no active consumers and:

• the queue is persistent and there are no messages
• the queue is temporary and the corresponding connection is closed

Specified by:

canDestroy in class DestinationCache

Returns:

true if the cache can be destroyed, otherwise false

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object