org.apache.camel.processor
Class Aggregator

java.lang.Object
  org.apache.camel.impl.ServiceSupport
      org.apache.camel.processor.BatchProcessor
          org.apache.camel.processor.Aggregator

All Implemented Interfaces:

Navigate<Processor>, Processor, Traceable, Service

public class Aggregator
extends BatchProcessor
implements Traceable

An implementation of the Aggregator pattern where a batch of messages are processed (up to a maximum amount or until some timeout is reached) and messages for the same correlation key are combined together using some kind of AggregationStrategy (by default the latest message is used) to compress many message exchanges into a smaller number of exchanges.

A good example of this is stock market data; you may be receiving 30,000 messages/second and you may want to throttle it right down so that multiple messages for the same stock are combined (or just the latest message is used and older prices are discarded). Another idea is to combine line item messages together into a single invoice message.

Version:

$Revision: 836213 $

Field Summary

Fields inherited from class org.apache.camel.processor.BatchProcessor

DEFAULT_BATCH_SIZE, DEFAULT_BATCH_TIMEOUT

Constructor Summary

Aggregator(Processor processor, AggregationCollection collection)

Aggregator(Processor processor, Expression correlationExpression, AggregationStrategy aggregationStrategy)

Aggregator(Processor processor, Expression correlationExpression, AggregationStrategy aggregationStrategy, Predicate aggregationCompletedPredicate)

Method Summary

String	getTraceLabel() Gets the trace label used for logging when tracing is enabled.
String	toString()

Methods inherited from class org.apache.camel.processor.BatchProcessor

doStart, doStop, getBatchSize, getBatchTimeout, getExceptionHandler, getOutBatchSize, getProcessor, hasNext, isBatchConsumer, isGroupExchanges, next, process, processExchange, setBatchConsumer, setBatchSize, setBatchTimeout, setExceptionHandler, setGroupExchanges, setOutBatchSize

Methods inherited from class org.apache.camel.impl.ServiceSupport

addChildService, getStatus, getVersion, isRunAllowed, isStarted, isStarting, isStopped, isStopping, removeChildService, start, stop

Methods inherited from class java.lang.Object

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

Constructor Detail

Aggregator

public Aggregator(Processor processor,
                  Expression correlationExpression,
                  AggregationStrategy aggregationStrategy)

Aggregator

public Aggregator(Processor processor,
                  Expression correlationExpression,
                  AggregationStrategy aggregationStrategy,
                  Predicate aggregationCompletedPredicate)

Aggregator

public Aggregator(Processor processor,
                  AggregationCollection collection)

Method Detail

toString

public String toString()

Overrides:

toString in class BatchProcessor

getTraceLabel

public String getTraceLabel()

Description copied from interface: Traceable

Gets the trace label used for logging when tracing is enabled.

The label should be short and precise.

Specified by:

getTraceLabel in interface Traceable

Returns:

the label