com.atomikos.jms
Class QueueReceiverSessionPool

java.lang.Object
  com.atomikos.jms.MessageConsumerSessionPool
      com.atomikos.jms.QueueReceiverSessionPool

public class QueueReceiverSessionPool
extends MessageConsumerSessionPool

A pool of QueueReceiverSession instances, for activating multiple threads on the same queue. Upon start, an instance of this class will create a number of concurrent sessions that listen for incoming messages on the same queue. MessageListener instances should be thread-safe if the pool size is larger than one. Note: in general, after start() any changed properties are only effective on the next start() event.

IMPORTANT: the transactional behaviour guarantees redelivery after failures. As a side-effect, this can lead to so-called poison messages: messages whose processing repeatedly fails due to some recurring error (for instance, a primary key violation in the database, a NullPointerException, ...). Poison messages are problematic because they can prevent other messages from being processed, and block the system. Some messaging systems provide a way to deal with poison messages, others don't. In that case, it is up to the registered MessageListener to detect poison messages. The easiest way to detect these is by inspecting the JMSRedelivered header and/or the (sometimes available) JMS property called JMSXDeliveryCount. For instance, if the delivery count is too high then your application may choose to send the message to a dedicated problem queue and thereby avoid processing errors. Whatever you do, beware that messages are sometimes correctly redelivered, in particular after a prior crash of the application.

Constructor Summary

QueueReceiverSessionPool()

Method Summary

protected MessageConsumerSession	createSession()
protected boolean	getNoLocal()
javax.jms.Queue	getQueue() Get the queue to listen on.
QueueConnectionFactoryBean	getQueueConnectionFactoryBean() Get the connection factory bean.
protected String	getSubscriberName()
void	setQueue(javax.jms.Queue queue) Set the queue to listen on (required).
void	setQueueConnectionFactoryBean(QueueConnectionFactoryBean bean) Set the connection factory to use (required).

Methods inherited from class com.atomikos.jms.MessageConsumerSessionPool

getAbstractConnectionFactoryBean, getDaemonThreads, getDestination, getExceptionListener, getMessageListener, getMessageSelector, getNotifyListenerOnClose, getPoolSize, getTransactionTimeout, getUser, setAbstractConnectionFactoryBean, setDaemonThreads, setDestination, setExceptionListener, setMessageListener, setMessageSelector, setNotifyListenerOnClose, setPassword, setPoolSize, setTransactionTimeout, setUser, start, stop

Methods inherited from class java.lang.Object

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

Constructor Detail

QueueReceiverSessionPool

public QueueReceiverSessionPool()

Method Detail

getQueue

public javax.jms.Queue getQueue()

Get the queue to listen on.

Returns:

getQueueConnectionFactoryBean

public QueueConnectionFactoryBean getQueueConnectionFactoryBean()

Get the connection factory bean.

Returns:

setQueue

public void setQueue(javax.jms.Queue queue)

Set the queue to listen on (required).

Parameters:

queue -

setQueueConnectionFactoryBean

public void setQueueConnectionFactoryBean(QueueConnectionFactoryBean bean)

Set the connection factory to use (required).

Parameters:

bean -

createSession

protected MessageConsumerSession createSession()

Specified by:

createSession in class MessageConsumerSessionPool

getNoLocal

protected boolean getNoLocal()

Specified by:

getNoLocal in class MessageConsumerSessionPool

getSubscriberName

protected String getSubscriberName()

Specified by:

getSubscriberName in class MessageConsumerSessionPool