org.springframework.integration.aggregator
Class AbstractMessageAggregator

java.lang.Object
  org.springframework.integration.handler.AbstractMessageHandler
      org.springframework.integration.aggregator.AbstractMessageBarrierHandler<java.util.List<Message<?>>>
          org.springframework.integration.aggregator.AbstractMessageAggregator

All Implemented Interfaces:

org.springframework.beans.factory.BeanFactoryAware, org.springframework.beans.factory.InitializingBean, org.springframework.core.Ordered, MessageHandler

Direct Known Subclasses:

DefaultMessageAggregator, MethodInvokingAggregator

public abstract class AbstractMessageAggregator
extends AbstractMessageBarrierHandler<java.util.List<Message<?>>>

A base class for aggregating a group of Messages into a single Message. Extends AbstractMessageBarrierHandler and waits for a complete group of Messages to arrive. Subclasses must provide the implementation of the aggregateMessages(List) method to combine the group of Messages into a single Message.

The default strategy for determining whether a group is complete is based on the 'sequenceSize' property of the header. Alternatively, a custom implementation of the CompletionStrategy may be provided.

All considerations regarding timeout and grouping by correlationId from AbstractMessageBarrierHandler apply here as well.

Author:

Mark Fisher, Marius Bogoevici

Field Summary

Fields inherited from class org.springframework.integration.aggregator.AbstractMessageBarrierHandler

barriers, DEFAULT_REAPER_INTERVAL, DEFAULT_SEND_TIMEOUT, DEFAULT_TIMEOUT, DEFAULT_TRACKED_CORRRELATION_ID_CAPACITY, logger, trackedCorrelationIds

Fields inherited from interface org.springframework.core.Ordered

HIGHEST_PRECEDENCE, LOWEST_PRECEDENCE

Constructor Summary

AbstractMessageAggregator()

Method Summary

protected abstract Message<?>	aggregateMessages(java.util.List<Message<?>> messages)
protected MessageBarrier<java.util.List<Message<?>>>	createMessageBarrier(java.lang.Object correlationKey) Factory method for creating a MessageBarrier implementation.
protected void	processBarrier(MessageBarrier<java.util.List<Message<?>>> barrier) A method for processing the information in the message barrier after a message has been added or on pruning.
void	setCompletionStrategy(CompletionStrategy completionStrategy) Strategy to determine whether the group of messages is complete.

Methods inherited from class org.springframework.integration.aggregator.AbstractMessageBarrierHandler

afterPropertiesSet, canAddMessage, discardBarrier, handleMessageInternal, isRunning, removeBarrier, resolveReplyChannelFromMessage, sendReplies, sendReply, setAutoStartup, setBeanFactory, setCorrelationStrategy, setDiscardChannel, setOutputChannel, setReaperInterval, setSendPartialResultOnTimeout, setSendTimeout, setTaskScheduler, setTimeout, setTrackedCorrelationIdCapacity, start, stop

Methods inherited from class org.springframework.integration.handler.AbstractMessageHandler

getOrder, handleMessage, setOrder

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractMessageAggregator

public AbstractMessageAggregator()

Method Detail

setCompletionStrategy

public void setCompletionStrategy(CompletionStrategy completionStrategy)

Strategy to determine whether the group of messages is complete.

createMessageBarrier

protected MessageBarrier<java.util.List<Message<?>>> createMessageBarrier(java.lang.Object correlationKey)

Description copied from class: AbstractMessageBarrierHandler

Factory method for creating a MessageBarrier implementation.

Specified by:

createMessageBarrier in class AbstractMessageBarrierHandler<java.util.List<Message<?>>>

processBarrier

protected void processBarrier(MessageBarrier<java.util.List<Message<?>>> barrier)

Description copied from class: AbstractMessageBarrierHandler

A method for processing the information in the message barrier after a message has been added or on pruning. The decision as to whether the messages from the MessageBarrier can be released normally belongs here, although calling code may forcibly set the MessageBarrier's 'complete' flag to true before invoking the method.

Specified by:

processBarrier in class AbstractMessageBarrierHandler<java.util.List<Message<?>>>

Parameters:

barrier - the MessageBarrier to be processed

aggregateMessages

protected abstract Message<?> aggregateMessages(java.util.List<Message<?>> messages)