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Posted to commits@camel.apache.org by bu...@apache.org on 2017/08/25 08:22:03 UTC
svn commit: r1017260 [2/40] - in /websites/production/camel/content: ./
cache/
Modified: websites/production/camel/content/aggregator2.html
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--- websites/production/camel/content/aggregator2.html (original)
+++ websites/production/camel/content/aggregator2.html Fri Aug 25 08:22:01 2017
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Apache Camel: Aggregator2
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-<div class="wiki-content maincontent"><h3 id="Aggregator2-Aggregator">Aggregator</h3><p><strong>This applies for Camel version 2.3 or newer. If you use an older version then use this <a shape="rect" href="aggregator.html">Aggregator</a> link instead.</strong></p><p>The <a shape="rect" class="external-link" href="http://www.enterpriseintegrationpatterns.com/Aggregator.html" rel="nofollow">Aggregator</a> from the <a shape="rect" href="enterprise-integration-patterns.html">EIP patterns</a> allows you to combine a number of messages together into a single message.</p><p><span class="confluence-embedded-file-wrapper"><img class="confluence-embedded-image confluence-external-resource" src="http://www.enterpriseintegrationpatterns.com/img/Aggregator.gif" data-image-src="http://www.enterpriseintegrationpatterns.com/img/Aggregator.gif"></span></p><p>A correlation <a shape="rect" href="expression.html">Expression</a> is used to determine the messages which should be aggregated together. If yo
u want to aggregate all messages into a single message, just use a constant expression. An AggregationStrategy is used to combine all the message exchanges for a single correlation key into a single message exchange.</p><h3 id="Aggregator2-Aggregatoroptions">Aggregator options</h3><p>The aggregator supports the following options:</p><div class="confluenceTableSmall"><div class="table-wrap"><table class="confluenceTable"><tbody><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Option</p></th><th colspan="1" rowspan="1" class="confluenceTh"><p>Default</p></th><th colspan="1" rowspan="1" class="confluenceTh"><p>Description</p></th></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>correlationExpression</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Mandatory <a shape="rect" href="expression.html">Expression</a> which evaluates the correlation key to use for aggregation. The <a shape="rect" h
ref="exchange.html">Exchange</a> which has the same correlation key is aggregated together. If the correlation key could not be evaluated an Exception is thrown. You can disable this by using the <code>ignoreBadCorrelationKeys</code> option.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>aggregationStrategy</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Mandatory <code>AggregationStrategy</code> which is used to <em>merge</em> the incoming <a shape="rect" href="exchange.html">Exchange</a> with the existing already merged exchanges. At first call the <code>oldExchange</code> parameter is <code>null</code>. On subsequent invocations the <code>oldExchange</code> contains the merged exchanges and <code>newExchange</code> is of course the new incoming Exchange. From <strong>Camel 2.9.2</strong> onwards the strategy can also be a <code>TimeoutAwareAggregationStrategy</code> implementation
, supporting the timeout callback, see further below for more details. From <strong>Camel 2.16</strong> onwards the strategy can also be a <code>PreCompletionAwareAggregationStrategy</code> implementation which then runs the completion check in pre-completion mode. See further below for more details.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>strategyRef</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>A reference to lookup the <code>AggregationStrategy</code> in the <a shape="rect" href="registry.html">Registry</a>. From <strong>Camel 2.12</strong> onwards you can also use a POJO as the <code>AggregationStrategy</code>, see further below for details.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>strategyMethodName</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><strong>Camel 2.12
:</strong> This option can be used to explicit declare the method name to use, when using POJOs as the <code>AggregationStrategy</code>. See further below for more details.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>strategyMethodAllowNull</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><code>false</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><strong>Camel 2.12:</strong> If this option is <code>false</code> then the aggregate method is not used for the very first aggregation. If this option is <code>true</code> then <code>null</code> values is used as the <code>oldExchange</code> (at the very first aggregation), when using POJOs as the <code>AggregationStrategy</code>. See further below for more details.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>completionSize</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Number of me
ssages aggregated before the aggregation is complete. This option can be set as either a fixed value or using an <a shape="rect" href="expression.html">Expression</a> which allows you to evaluate a size dynamically - will use <code>Integer</code> as result. If both are set Camel will fallback to use the fixed value if the <a shape="rect" href="expression.html">Expression</a> result was <code>null</code> or <code>0</code>.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>completionTimeout</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Time in millis that an aggregated exchange should be inactive before its complete. This option can be set as either a fixed value or using an <a shape="rect" href="expression.html">Expression</a> which allows you to evaluate a timeout dynamically - will use <code>Long</code> as result. If both are set Camel will fallback to use the fixed value if the <a s
hape="rect" href="expression.html">Expression</a> result was <code>null</code> or <code>0</code>. You cannot use this option together with completionInterval, only one of the two can be used.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>completionInterval</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>A repeating period in millis by which the aggregator will complete all current aggregated exchanges. Camel has a background task which is triggered every period. You cannot use this option together with completionTimeout, only one of them can be used.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>completionPredicate</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>A <a shape="rect" href="predicate.html">Predicate</a> to indicate when an aggregated exchange is complete. Starting in <st
rong>Camel 2.15</strong>, if this is not specified and the AggregationStrategy object implements Predicate, the aggregationStrategy object will be used as the completionPredicate.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>completionFromBatchConsumer</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><code>false</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>This option is if the exchanges are coming from a <a shape="rect" href="batch-consumer.html">Batch Consumer</a>. Then when enabled the <a shape="rect" href="aggregator2.html">Aggregator2</a> will use the batch size determined by the <a shape="rect" href="batch-consumer.html">Batch Consumer</a> in the message header <code>CamelBatchSize</code>. See more details at <a shape="rect" href="batch-consumer.html">Batch Consumer</a>. This can be used to aggregate all files consumed from a <a shape="rect" href="file2.html">File</a> endpoint in that given poll.</p></td></tr><tr><td col
span="1" rowspan="1" class="confluenceTd"><p>forceCompletionOnStop</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><code>false</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><strong>Camel 2.9</strong> Indicates to complete all current aggregated exchanges when the context is stopped</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd">completeAllOnStop</td><td colspan="1" rowspan="1" class="confluenceTd"><code>false</code></td><td colspan="1" rowspan="1" class="confluenceTd"><strong>Camel 2.16:</strong> Indicates to wait to complete all current and partial (pending) aggregated exchanges when the context is stopped. This also means that we will wait for all pending exchanges which are stored in the aggregation repository to complete so the repository is empty before we can stop.  You may want to enable this when using the memory based aggregation repository that is memory based only, and do not store data on disk.
When this option is enabled, then the aggregator is waiting to complete all those exchanges before its stopped, when stopping CamelContext or the route using it.</td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>eagerCheckCompletion</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><code>false</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Whether or not to eager check for completion when a new incoming <a shape="rect" href="exchange.html">Exchange</a> has been received. This option influences the behavior of the <code>completionPredicate</code> option as the <a shape="rect" href="exchange.html">Exchange</a> being passed in changes accordingly. When <code>false</code> the <a shape="rect" href="exchange.html">Exchange</a> passed in the <a shape="rect" href="predicate.html">Predicate</a> is the <em>aggregated</em> Exchange which means any information you may store on the aggregated Exchange from the <code>AggregationStrategy</code> is
available for the <a shape="rect" href="predicate.html">Predicate</a>. When <code>true</code> the <a shape="rect" href="exchange.html">Exchange</a> passed in the <a shape="rect" href="predicate.html">Predicate</a> is the <em>incoming</em> <a shape="rect" href="exchange.html">Exchange</a>, which means you can access data from the incoming Exchange.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>groupExchanges</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><code>false</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>If enabled then Camel will group all aggregated Exchanges into a single combined <code>org.apache.camel.impl.GroupedExchange</code> holder class that holds all the aggregated Exchanges. And as a result only one Exchange is being sent out from the aggregator. Can be used to combine many incoming Exchanges into a single output Exchange without coding a custom <code>AggregationStrategy</code> yourself. <strong>Important:</s
trong> This option does <strong>not</strong> support persistent repository with the aggregator. See further below for an example and more details.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>ignoreInvalidCorrelationKeys</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><code>false</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Whether or not to ignore correlation keys which could not be evaluated to a value. By default Camel will throw an Exception, but you can enable this option and ignore the situation instead.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>closeCorrelationKeyOnCompletion</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Whether or not too <em>late</em> Exchanges should be accepted or not. You can enable this to indicate that if a correlation key has already been completed, then any new exchanges with the same co
rrelation key be denied. Camel will then throw a <code>closedCorrelationKeyException</code> exception. When using this option you pass in a <code>integer</code> which is a number for a LRUCache which keeps that last X number of closed correlation keys. You can pass in 0 or a negative value to indicate a unbounded cache. By passing in a number you are ensured that cache won't grow too big if you use a log of different correlation keys.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>discardOnCompletionTimeout</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><code>false</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><strong>Camel 2.5:</strong> Whether or not exchanges which complete due to a timeout should be discarded. If enabled then when a timeout occurs the aggregated message will <strong>not</strong> be sent out but dropped (discarded).</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>aggregationRepository</p
></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Allows you to plugin you own implementation of <code>org.apache.camel.spi.AggregationRepository</code> which keeps track of the current inflight aggregated exchanges. Camel uses by default a memory based implementation.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>aggregationRepositoryRef</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Reference to lookup a <code>aggregationRepository</code> in the <a shape="rect" href="registry.html">Registry</a>.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>parallelProcessing</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><code>false</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>When aggregated are completed they are being send out of the aggregator. This option indi
cates whether or not Camel should use a thread pool with multiple threads for concurrency. If no custom thread pool has been specified then Camel creates a default pool with 10 concurrent threads.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>executorService</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>If using <code>parallelProcessing</code> you can specify a custom thread pool to be used. In fact also if you are not using <code>parallelProcessing</code> this custom thread pool is used to send out aggregated exchanges as well.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>executorServiceRef</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Reference to lookup a <code>executorService</code> in the <a shape="rect" href="registry.html">Registry</a></p></td></tr><tr><td colspan="1" ro
wspan="1" class="confluenceTd"><p>timeoutCheckerExecutorService</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><strong>Camel 2.9:</strong> If using either of the <code>completionTimeout</code>, <code>completionTimeoutExpression</code>, or <code>completionInterval</code> options a background thread is created to check for the completion for every aggregator. Set this option to provide a custom thread pool to be used rather than creating a new thread for every aggregator.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>timeoutCheckerExecutorServiceRef</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><strong>Camel 2.9:</strong> Reference to lookup a <code>timeoutCheckerExecutorService</code> in the <a shape="rect" href="registry.html">Registry</a></p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceT
d"><p>optimisticLocking</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><code>false</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><strong>Camel 2.11:</strong> Turns on using optimistic locking, which requires the <code>aggregationRepository</code> being used, is supporting this by implementing the <code>org.apache.camel.spi.OptimisticLockingAggregationRepository</code> interface.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>optimisticLockRetryPolicy</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><strong>Camel 2.11.1:</strong> Allows to configure retry settings when using optimistic locking.</p></td></tr></tbody></table></div></div>
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-<h3 id="Aggregator2-ExchangeProperties">Exchange Properties</h3><p>The following properties are set on each aggregated Exchange:</p><div class="confluenceTableSmall"><div class="table-wrap"><table class="confluenceTable"><tbody><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>header</p></th><th colspan="1" rowspan="1" class="confluenceTh"><p>type</p></th><th colspan="1" rowspan="1" class="confluenceTh"><p>description</p></th></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>CamelAggregatedSize</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>int</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>The total number of Exchanges aggregated into this combined Exchange.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>CamelAggregatedCompletedBy</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>String</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Indicator how the aggregation was com
pleted as a value of either: <code>predicate</code>, <code>size</code>, <code>strategy</code>, <code>consumer</code>, <code>timeout</code>, <code>forceCompletion</code> or <code>interval</code>.</p></td></tr></tbody></table></div></div>
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-
-<h3 id="Aggregator2-AboutAggregationStrategy">About AggregationStrategy</h3><p>The <code>AggregationStrategy</code> is used for aggregating the old (lookup by its correlation id) and the new exchanges together into a single exchange. Possible implementations include performing some kind of combining or delta processing, such as adding line items together into an invoice or just using the newest exchange and removing old exchanges such as for state tracking or market data prices; where old values are of little use.</p><p>Notice the aggregation strategy is a mandatory option and must be provided to the aggregator.</p><p>Here are a few example AggregationStrategy implementations that should help you create your own custom strategy.</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[//simply combines Exchange String body values using '+' as a delimiter
+<div class="wiki-content maincontent"><h3 id="Aggregator2-Aggregator">Aggregator</h3><p><strong>This applies for Camel version 2.3 or newer. If you use an older version then use this <a shape="rect" href="aggregator.html">Aggregator</a> link instead.</strong></p><p>The <a shape="rect" class="external-link" href="http://www.enterpriseintegrationpatterns.com/Aggregator.html" rel="nofollow">Aggregator</a> from the <a shape="rect" href="enterprise-integration-patterns.html">EIP patterns</a> allows you to combine a number of messages together into a single message.</p><p><span class="confluence-embedded-file-wrapper"><img class="confluence-embedded-image confluence-external-resource" src="http://www.enterpriseintegrationpatterns.com/img/Aggregator.gif" data-image-src="http://www.enterpriseintegrationpatterns.com/img/Aggregator.gif"></span></p><p>A correlation <a shape="rect" href="expression.html">Expression</a> is used to determine the messages which should be aggregated together. If yo
u want to aggregate all messages into a single message, just use a constant expression. An AggregationStrategy is used to combine all the message exchanges for a single correlation key into a single message exchange.</p><h3 id="Aggregator2-Aggregatoroptions">Aggregator options</h3><p>The aggregator supports the following options:</p><parameter ac:name="class">confluenceTableSmall</parameter><rich-text-body><div class="table-wrap"><table class="confluenceTable"><tbody><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Option</p></th><th colspan="1" rowspan="1" class="confluenceTh"><p>Default</p></th><th colspan="1" rowspan="1" class="confluenceTh"><p>Description</p></th></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>correlationExpression</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Mandatory <a shape="rect" href="expression.html">Expression</a> which evaluates the correlation key to u
se for aggregation. The <a shape="rect" href="exchange.html">Exchange</a> which has the same correlation key is aggregated together. If the correlation key could not be evaluated an Exception is thrown. You can disable this by using the <code>ignoreBadCorrelationKeys</code> option.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>aggregationStrategy</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Mandatory <code>AggregationStrategy</code> which is used to <em>merge</em> the incoming <a shape="rect" href="exchange.html">Exchange</a> with the existing already merged exchanges. At first call the <code>oldExchange</code> parameter is <code>null</code>. On subsequent invocations the <code>oldExchange</code> contains the merged exchanges and <code>newExchange</code> is of course the new incoming Exchange. From <strong>Camel 2.9.2</strong> onwards the strategy can also be a <code>TimeoutAware
AggregationStrategy</code> implementation, supporting the timeout callback, see further below for more details. From <strong>Camel 2.16</strong> onwards the strategy can also be a <code>PreCompletionAwareAggregationStrategy</code> implementation which then runs the completion check in pre-completion mode. See further below for more details.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>strategyRef</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>A reference to lookup the <code>AggregationStrategy</code> in the <a shape="rect" href="registry.html">Registry</a>. From <strong>Camel 2.12</strong> onwards you can also use a POJO as the <code>AggregationStrategy</code>, see further below for details.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>strategyMethodName</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" c
lass="confluenceTd"><p><strong>Camel 2.12:</strong> This option can be used to explicit declare the method name to use, when using POJOs as the <code>AggregationStrategy</code>. See further below for more details.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>strategyMethodAllowNull</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><code>false</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><strong>Camel 2.12:</strong> If this option is <code>false</code> then the aggregate method is not used for the very first aggregation. If this option is <code>true</code> then <code>null</code> values is used as the <code>oldExchange</code> (at the very first aggregation), when using POJOs as the <code>AggregationStrategy</code>. See further below for more details.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>completionSize</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan
="1" class="confluenceTd"><p>Number of messages aggregated before the aggregation is complete. This option can be set as either a fixed value or using an <a shape="rect" href="expression.html">Expression</a> which allows you to evaluate a size dynamically - will use <code>Integer</code> as result. If both are set Camel will fallback to use the fixed value if the <a shape="rect" href="expression.html">Expression</a> result was <code>null</code> or <code>0</code>.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>completionTimeout</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Time in millis that an aggregated exchange should be inactive before its complete. This option can be set as either a fixed value or using an <a shape="rect" href="expression.html">Expression</a> which allows you to evaluate a timeout dynamically - will use <code>Long</code> as result. If both are set Camel will fa
llback to use the fixed value if the <a shape="rect" href="expression.html">Expression</a> result was <code>null</code> or <code>0</code>. You cannot use this option together with completionInterval, only one of the two can be used.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>completionInterval</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>A repeating period in millis by which the aggregator will complete all current aggregated exchanges. Camel has a background task which is triggered every period. You cannot use this option together with completionTimeout, only one of them can be used.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>completionPredicate</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>A <a shape="rect" href="predicate.html">Predicate</a> to indicate when an aggrega
ted exchange is complete. Starting in <strong>Camel 2.15</strong>, if this is not specified and the AggregationStrategy object implements Predicate, the aggregationStrategy object will be used as the completionPredicate.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>completionFromBatchConsumer</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><code>false</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>This option is if the exchanges are coming from a <a shape="rect" href="batch-consumer.html">Batch Consumer</a>. Then when enabled the <a shape="rect" href="aggregator2.html">Aggregator2</a> will use the batch size determined by the <a shape="rect" href="batch-consumer.html">Batch Consumer</a> in the message header <code>CamelBatchSize</code>. See more details at <a shape="rect" href="batch-consumer.html">Batch Consumer</a>. This can be used to aggregate all files consumed from a <a shape="rect" href="file2.html">File</a> endpoint in
that given poll.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>forceCompletionOnStop</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><code>false</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><strong>Camel 2.9</strong> Indicates to complete all current aggregated exchanges when the context is stopped</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd">completeAllOnStop</td><td colspan="1" rowspan="1" class="confluenceTd"><code>false</code></td><td colspan="1" rowspan="1" class="confluenceTd"><strong>Camel 2.16:</strong> Indicates to wait to complete all current and partial (pending) aggregated exchanges when the context is stopped. This also means that we will wait for all pending exchanges which are stored in the aggregation repository to complete so the repository is empty before we can stop.  You may want to enable this when using the memory based aggregation repository that is memory based o
nly, and do not store data on disk. When this option is enabled, then the aggregator is waiting to complete all those exchanges before its stopped, when stopping CamelContext or the route using it.</td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>eagerCheckCompletion</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><code>false</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Whether or not to eager check for completion when a new incoming <a shape="rect" href="exchange.html">Exchange</a> has been received. This option influences the behavior of the <code>completionPredicate</code> option as the <a shape="rect" href="exchange.html">Exchange</a> being passed in changes accordingly. When <code>false</code> the <a shape="rect" href="exchange.html">Exchange</a> passed in the <a shape="rect" href="predicate.html">Predicate</a> is the <em>aggregated</em> Exchange which means any information you may store on the aggregated Exchange from
the <code>AggregationStrategy</code> is available for the <a shape="rect" href="predicate.html">Predicate</a>. When <code>true</code> the <a shape="rect" href="exchange.html">Exchange</a> passed in the <a shape="rect" href="predicate.html">Predicate</a> is the <em>incoming</em> <a shape="rect" href="exchange.html">Exchange</a>, which means you can access data from the incoming Exchange.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>groupExchanges</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><code>false</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>If enabled then Camel will group all aggregated Exchanges into a single combined <code>org.apache.camel.impl.GroupedExchange</code> holder class that holds all the aggregated Exchanges. And as a result only one Exchange is being sent out from the aggregator. Can be used to combine many incoming Exchanges into a single output Exchange without coding a custom <code>AggregationStrate
gy</code> yourself. <strong>Important:</strong> This option does <strong>not</strong> support persistent repository with the aggregator. See further below for an example and more details.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>ignoreInvalidCorrelationKeys</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><code>false</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Whether or not to ignore correlation keys which could not be evaluated to a value. By default Camel will throw an Exception, but you can enable this option and ignore the situation instead.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>closeCorrelationKeyOnCompletion</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Whether or not too <em>late</em> Exchanges should be accepted or not. You can enable this to indicate that if a correlation key has already been completed
, then any new exchanges with the same correlation key be denied. Camel will then throw a <code>closedCorrelationKeyException</code> exception. When using this option you pass in a <code>integer</code> which is a number for a LRUCache which keeps that last X number of closed correlation keys. You can pass in 0 or a negative value to indicate a unbounded cache. By passing in a number you are ensured that cache won't grow too big if you use a log of different correlation keys.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>discardOnCompletionTimeout</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><code>false</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><strong>Camel 2.5:</strong> Whether or not exchanges which complete due to a timeout should be discarded. If enabled then when a timeout occurs the aggregated message will <strong>not</strong> be sent out but dropped (discarded).</p></td></tr><tr><td colspan="1" rowspan="1" class="
confluenceTd"><p>aggregationRepository</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Allows you to plugin you own implementation of <code>org.apache.camel.spi.AggregationRepository</code> which keeps track of the current inflight aggregated exchanges. Camel uses by default a memory based implementation.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>aggregationRepositoryRef</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Reference to lookup a <code>aggregationRepository</code> in the <a shape="rect" href="registry.html">Registry</a>.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>parallelProcessing</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><code>false</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>When aggregated are completed they are being sen
d out of the aggregator. This option indicates whether or not Camel should use a thread pool with multiple threads for concurrency. If no custom thread pool has been specified then Camel creates a default pool with 10 concurrent threads.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>executorService</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>If using <code>parallelProcessing</code> you can specify a custom thread pool to be used. In fact also if you are not using <code>parallelProcessing</code> this custom thread pool is used to send out aggregated exchanges as well.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>executorServiceRef</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Reference to lookup a <code>executorService</code> in the <a shape="rect" href="registry.html">Registr
y</a></p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>timeoutCheckerExecutorService</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><strong>Camel 2.9:</strong> If using either of the <code>completionTimeout</code>, <code>completionTimeoutExpression</code>, or <code>completionInterval</code> options a background thread is created to check for the completion for every aggregator. Set this option to provide a custom thread pool to be used rather than creating a new thread for every aggregator.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>timeoutCheckerExecutorServiceRef</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><strong>Camel 2.9:</strong> Reference to lookup a <code>timeoutCheckerExecutorService</code> in the <a shape="rect" href="registry.html">Registry</a></p></td></tr><tr><td c
olspan="1" rowspan="1" class="confluenceTd"><p>optimisticLocking</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><code>false</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><strong>Camel 2.11:</strong> Turns on using optimistic locking, which requires the <code>aggregationRepository</code> being used, is supporting this by implementing the <code>org.apache.camel.spi.OptimisticLockingAggregationRepository</code> interface.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>optimisticLockRetryPolicy</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><strong>Camel 2.11.1:</strong> Allows to configure retry settings when using optimistic locking.</p></td></tr></tbody></table></div></rich-text-body><h3 id="Aggregator2-ExchangeProperties">Exchange Properties</h3><p>The following properties are set on each aggregated Exchange:</p><parameter ac:name="class">confluence
TableSmall</parameter><rich-text-body><div class="table-wrap"><table class="confluenceTable"><tbody><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>header</p></th><th colspan="1" rowspan="1" class="confluenceTh"><p>type</p></th><th colspan="1" rowspan="1" class="confluenceTh"><p>description</p></th></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>CamelAggregatedSize</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>int</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>The total number of Exchanges aggregated into this combined Exchange.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>CamelAggregatedCompletedBy</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>String</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Indicator how the aggregation was completed as a value of either: <code>predicate</code>, <code>size</code>, <code>strategy</code>, <code>consumer</code>, <code>time
out</code>, <code>forceCompletion</code> or <code>interval</code>.</p></td></tr></tbody></table></div></rich-text-body><h3 id="Aggregator2-AboutAggregationStrategy">About AggregationStrategy</h3><p>The <code>AggregationStrategy</code> is used for aggregating the old (lookup by its correlation id) and the new exchanges together into a single exchange. Possible implementations include performing some kind of combining or delta processing, such as adding line items together into an invoice or just using the newest exchange and removing old exchanges such as for state tracking or market data prices; where old values are of little use.</p><p>Notice the aggregation strategy is a mandatory option and must be provided to the aggregator.</p><p>Here are a few example AggregationStrategy implementations that should help you create your own custom strategy.</p><plain-text-body>//simply combines Exchange String body values using '+' as a delimiter
class StringAggregationStrategy implements AggregationStrategy {
public Exchange aggregate(Exchange oldExchange, Exchange newExchange) {
@@ -103,7 +85,7 @@ class StringAggregationStrategy implemen
String oldBody = oldExchange.getIn().getBody(String.class);
String newBody = newExchange.getIn().getBody(String.class);
- oldExchange.getIn().setBody(oldBody + "+" + newBody);
+ oldExchange.getIn().setBody(oldBody + "+" + newBody);
return oldExchange;
}
}
@@ -126,9 +108,7 @@ class ArrayListAggregationStrategy imple
}
}
}
-]]></script>
-</div></div><h3 id="Aggregator2-Aboutcompletion">About completion</h3><p>When aggregation <a shape="rect" href="exchange.html">Exchange</a>s at some point you need to indicate that the aggregated exchanges is complete, so they can be send out of the aggregator. Camel allows you to indicate completion in various ways as follows:</p><ul class="alternate"><li>completionTimeout - Is an inactivity timeout in which is triggered if no new exchanges have been aggregated for that particular correlation key within the period.</li><li>completionInterval - Once every X period all the current aggregated exchanges are completed.</li><li>completionSize - Is a number indicating that after X aggregated exchanges it's complete.</li><li>completionPredicate - Runs a <a shape="rect" href="predicate.html">Predicate</a> when a new exchange is aggregated to determine if we are complete or not. Staring in <strong>Camel 2.15</strong>, the configured aggregationStrategy can implement the Predicate interf
ace and will be used as the completionPredicate if no completionPredicate is configured. From <strong>Camel 2.16</strong>, the configured aggregationStrategy can implement <code>PreCompletionAwareAggregationStrategy</code> and will be used as the completionPredicate in pre-complete check mode. See further below for more details.</li><li>completionFromBatchConsumer - Special option for <a shape="rect" href="batch-consumer.html">Batch Consumer</a> which allows you to complete when all the messages from the batch has been aggregated.</li><li>forceCompletionOnStop - <strong>Camel 2.9</strong> Indicates to complete all current aggregated exchanges when the context is stopped</li><li>Using a <code>AggregateController</code> - <strong>Camel 2.16</strong> which allows to use an external source to complete groups or all groups. This can be done using Java or JMX API.</li></ul><p>Notice that all the completion ways are per correlation key. And you can combine them in any w
ay you like. It's basically the first which triggers that wins. So you can use a completion size together with a completion timeout. Only completionTimeout and completionInterval cannot be used at the same time.</p><p>Notice the completion is a mandatory option and must be provided to the aggregator. If not provided Camel will thrown an Exception on startup.</p><div class="confluence-information-macro confluence-information-macro-tip"><p class="title">Callbacks</p><span class="aui-icon aui-icon-small aui-iconfont-approve confluence-information-macro-icon"></span><div class="confluence-information-macro-body"><p>See the <code>TimeoutAwareAggregationStrategy</code> and <code>CompletionAwareAggregationStrategy</code> extensions to <code>AggregationStrategy</code> that has callbacks when the aggregated Exchange was completed and if a timeout occurred.</p></div></div><h3 id="Aggregator2-Pre-completionmode">Pre-completion mode</h3><p><strong>available as of Camel 2.16</strong></p><p>There
can be use-cases where you want the incoming <a shape="rect" href="exchange.html">Exchange</a> to determine if the correlation group should pre-complete, and then the incoming <a shape="rect" href="exchange.html">Exchange</a> is starting a new group from scratch. To determine this the <code>AggregationStrategy</code> can implement <code>PreCompletionAwareAggregationStrategy</code> which has a <code>preComplete</code> method:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[ /**
+</plain-text-body><h3 id="Aggregator2-Aboutcompletion">About completion</h3><p>When aggregation <a shape="rect" href="exchange.html">Exchange</a>s at some point you need to indicate that the aggregated exchanges is complete, so they can be send out of the aggregator. Camel allows you to indicate completion in various ways as follows:</p><ul class="alternate"><li>completionTimeout - Is an inactivity timeout in which is triggered if no new exchanges have been aggregated for that particular correlation key within the period.</li><li>completionInterval - Once every X period all the current aggregated exchanges are completed.</li><li>completionSize - Is a number indicating that after X aggregated exchanges it's complete.</li><li>completionPredicate - Runs a <a shape="rect" href="predicate.html">Predicate</a> when a new exchange is aggregated to determine if we are complete or not. Staring in <strong>Camel 2.15</strong>, the configured aggregationStrategy can implement the Predicate
interface and will be used as the completionPredicate if no completionPredicate is configured. From <strong>Camel 2.16</strong>, the configured aggregationStrategy can implement <code>PreCompletionAwareAggregationStrategy</code> and will be used as the completionPredicate in pre-complete check mode. See further below for more details.</li><li>completionFromBatchConsumer - Special option for <a shape="rect" href="batch-consumer.html">Batch Consumer</a> which allows you to complete when all the messages from the batch has been aggregated.</li><li>forceCompletionOnStop - <strong>Camel 2.9</strong> Indicates to complete all current aggregated exchanges when the context is stopped</li><li>Using a <code>AggregateController</code> - <strong>Camel 2.16</strong> which allows to use an external source to complete groups or all groups. This can be done using Java or JMX API.</li></ul><p>Notice that all the completion ways are per correlation key. And you can combine them in
any way you like. It's basically the first which triggers that wins. So you can use a completion size together with a completion timeout. Only completionTimeout and completionInterval cannot be used at the same time.</p><p>Notice the completion is a mandatory option and must be provided to the aggregator. If not provided Camel will thrown an Exception on startup.</p><parameter ac:name="title">Callbacks</parameter><rich-text-body><p>See the <code>TimeoutAwareAggregationStrategy</code> and <code>CompletionAwareAggregationStrategy</code> extensions to <code>AggregationStrategy</code> that has callbacks when the aggregated Exchange was completed and if a timeout occurred.</p></rich-text-body><h3 id="Aggregator2-Pre-completionmode">Pre-completion mode</h3><p><strong>available as of Camel 2.16</strong></p><p>There can be use-cases where you want the incoming <a shape="rect" href="exchange.html">Exchange</a> to determine if the correlation group should pre-complete, and then the inco
ming <a shape="rect" href="exchange.html">Exchange</a> is starting a new group from scratch. To determine this the <code>AggregationStrategy</code> can implement <code>PreCompletionAwareAggregationStrategy</code> which has a <code>preComplete</code> method:</p><plain-text-body> /**
* Determines if the aggregation should complete the current group, and start a new group, or the aggregation
* should continue using the current group.
*
@@ -136,187 +116,13 @@ class ArrayListAggregationStrategy imple
* @param newExchange the newest exchange (can be <tt>null</tt> if there was no data possible to acquire)
* @return <tt>true</tt> to complete current group and start a new group, or <tt>false</tt> to keep using current
*/
- boolean preComplete(Exchange oldExchange, Exchange newExchange);]]></script>
-</div></div><p>If the preComplete method returns true, then the existing groups is completed (without aggregating the incoming exchange (newExchange). And then the newExchange is used to start the correlation group from scratch so the group would contain only that new incoming exchange. This is known as pre-completion mode. And when the aggregation is in pre-completion mode, then only the following completions are in use</p><ul style="list-style-type: square;"><li>aggregationStrategy must implement <code>PreCompletionAwareAggregationStrategy</code> xxx</li><li>completionTimeout or completionInterval can also be used as fallback completions</li><li>any other completion are not used (such as by size, from batch consumer etc)</li><li>eagerCheckCompletion is implied as true, but the option has no effect</li></ul><h3 id="Aggregator2-PersistentAggregationRepository">Persistent AggregationRepository</h3><p>The aggregator provides a pluggable repository which you can implement you
r own <code>org.apache.camel.spi.AggregationRepository</code>.<br clear="none"> If you need persistent repository then you can use either Camel <a shape="rect" href="hawtdb.html">HawtDB</a>, <a shape="rect" href="leveldb.html">LevelDB</a>, or <a shape="rect" href="sql-component.html">SQL Component</a> components.</p><h3 id="Aggregator2-Examples">Examples</h3><p>See some examples from the old <a shape="rect" href="aggregator.html">Aggregator</a> which is somewhat similar to this new aggregator.</p><div class="confluence-information-macro confluence-information-macro-tip"><p class="title">Setting options in Spring XML</p><span class="aui-icon aui-icon-small aui-iconfont-approve confluence-information-macro-icon"></span><div class="confluence-information-macro-body"><p>Many of the options are configurable as attributes on the <code><aggregate></code> tag when using Spring XML.</p></div></div><h4 id="Aggregator2-UsingcompletionTimeout">Using completionTimeout</h4><p>In this exampl
e we want to aggregate all incoming messages and after 3 seconds of inactivity we want the aggregation to complete. This is done using the <code>completionTimeout</code> option as shown:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[
-from("direct:start")
- // aggregate all exchanges correlated by the id header.
- // Aggregate them using the BodyInAggregatingStrategy strategy which
- // and after 0.1 second of inactivity them timeout and complete the aggregation
- // and send it to mock:aggregated
- .aggregate(header("id"), new BodyInAggregatingStrategy()).completionTimeout(100).completionTimeoutCheckerInterval(10)
- .to("mock:aggregated");
-]]></script>
-</div></div>And the same example using Spring XML:<div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="brush: xml; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[
-<camelContext xmlns="http://camel.apache.org/schema/spring">
- <route>
- <from uri="direct:start"/>
- <aggregate strategyRef="aggregatorStrategy" completionTimeout="100" completionTimeoutCheckerInterval="10">
- <correlationExpression>
- <simple>header.id</simple>
- </correlationExpression>
- <to uri="mock:aggregated"/>
- </aggregate>
- </route>
-</camelContext>
-
-<bean id="aggregatorStrategy" class="org.apache.camel.processor.BodyInAggregatingStrategy"/>
-]]></script>
-</div></div><h4 id="Aggregator2-UsingTimeoutAwareAggregationStrategy">Using TimeoutAwareAggregationStrategy</h4><p><strong>Available as of Camel 2.9.2</strong></p><p>If your aggregation strategy implements <code>TimeoutAwareAggregationStrategy</code>, then Camel will invoke the <code>timeout</code> method when the timeout occurs. Notice that the values for index and total parameters will be -1, and the timeout parameter will be provided only if configured as a fixed value. You must <strong>not</strong> throw any exceptions from the <code>timeout</code> method.</p><h4 id="Aggregator2-UsingCompletionAwareAggregationStrategy">Using CompletionAwareAggregationStrategy</h4><p><strong>Available as of Camel 2.9.3</strong></p><p>If your aggregation strategy implements <code>CompletionAwareAggregationStrategy</code>, then Camel will invoke the <code>onComplete</code> method when the aggregated Exchange is completed. This allows you to do any last minute custom logic such as to cleanup some re
sources, or additional work on the exchange as it's now completed.<br clear="none"> You must <strong>not</strong> throw any exceptions from the <code>onCompletion</code> method.</p><h4 id="Aggregator2-UsingcompletionSize">Using completionSize</h4><p>In this example we want to aggregate all incoming messages and when we have 3 messages aggregated (in the same correlation group) we want the aggregation to complete. This is done using the <code>completionSize</code> option as shown:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[
-from("direct:start")
- // aggregate all exchanges correlated by the id header.
- // Aggregate them using the BodyInAggregatingStrategy strategy which
- // and after 3 messages has been aggregated then complete the aggregation
- // and send it to mock:aggregated
- .aggregate(header("id"), new BodyInAggregatingStrategy()).completionSize(3)
- .to("mock:aggregated");
-]]></script>
-</div></div>And the same example using Spring XML:<div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="brush: xml; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[
-<camelContext xmlns="http://camel.apache.org/schema/spring">
- <route>
- <from uri="direct:start"/>
- <aggregate strategyRef="aggregatorStrategy" completionSize="3">
- <correlationExpression>
- <simple>header.id</simple>
- </correlationExpression>
- <to uri="mock:aggregated"/>
- </aggregate>
- </route>
-</camelContext>
-
-<bean id="aggregatorStrategy" class="org.apache.camel.processor.BodyInAggregatingStrategy"/>
-]]></script>
-</div></div><h4 id="Aggregator2-UsingcompletionPredicate">Using completionPredicate</h4><p>In this example we want to aggregate all incoming messages and use a <a shape="rect" href="predicate.html">Predicate</a> to determine when we are complete. The <a shape="rect" href="predicate.html">Predicate</a> can be evaluated using either the aggregated exchange (default) or the incoming exchange. We will give an example for both situations. We start with the default situation as shown:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[
-from("direct:start")
- // aggregate all exchanges correlated by the id header.
- // Aggregate them using the BodyInAggregatingStrategy strategy which
- // and when the aggregated body contains A+B+C then complete the aggregation
- // and send it to mock:aggregated
- .aggregate(header("id"), new BodyInAggregatingStrategy()).completionPredicate(body().contains("A+B+C"))
- .to("mock:aggregated");
-]]></script>
-</div></div>And the same example using Spring XML:<div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="brush: xml; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[
-<camelContext xmlns="http://camel.apache.org/schema/spring">
- <route>
- <from uri="direct:start"/>
- <aggregate strategyRef="aggregatorStrategy">
- <correlationExpression>
- <simple>header.id</simple>
- </correlationExpression>
- <completionPredicate>
- <simple>${body} contains 'A+B+C'</simple>
- </completionPredicate>
- <to uri="mock:aggregated"/>
- </aggregate>
- </route>
-</camelContext>
-
-<bean id="aggregatorStrategy" class="org.apache.camel.processor.BodyInAggregatingStrategy"/>
-]]></script>
-</div></div>And the other situation where we use the <code>eagerCheckCompletion</code> option to tell Camel to use the incoming Exchange. Notice how we can just test in the completion predicate that the incoming message is the <em>END</em> message:<div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[
-from("direct:start")
- // aggregate all exchanges correlated by the id header.
- // Aggregate them using the BodyInAggregatingStrategy strategy
- // do eager checking which means the completion predicate will use the incoming exchange
- // which allows us to trigger completion when a certain exchange arrived which is the
- // END message
- .aggregate(header("id"), new BodyInAggregatingStrategy())
- .eagerCheckCompletion().completionPredicate(body().isEqualTo("END"))
- .to("mock:aggregated");
-]]></script>
-</div></div>And the same example using Spring XML:<div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="brush: xml; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[
-<camelContext xmlns="http://camel.apache.org/schema/spring">
- <route>
- <from uri="direct:start"/>
- <aggregate strategyRef="aggregatorStrategy" eagerCheckCompletion="true">
- <correlationExpression>
- <simple>header.id</simple>
- </correlationExpression>
- <completionPredicate>
- <simple>${body} == 'END'</simple>
- </completionPredicate>
- <to uri="mock:aggregated"/>
- </aggregate>
- </route>
-</camelContext>
-
-<bean id="aggregatorStrategy" class="org.apache.camel.processor.BodyInAggregatingStrategy"/>
-]]></script>
-</div></div><h4 id="Aggregator2-UsingdynamiccompletionTimeout">Using dynamic completionTimeout</h4><p>In this example we want to aggregate all incoming messages and after a period of inactivity we want the aggregation to complete. The period should be computed at runtime based on the <code>timeout</code> header in the incoming messages. This is done using the <code>completionTimeout</code> option as shown:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[
-from("direct:start")
- // aggregate all exchanges correlated by the id header.
- // Aggregate them using the BodyInAggregatingStrategy strategy which
- // and the timeout header contains the timeout in millis of inactivity them timeout and complete the aggregation
- // and send it to mock:aggregated
- .aggregate(header("id"), new BodyInAggregatingStrategy()).completionTimeout(header("timeout")).completionTimeoutCheckerInterval(10)
- .to("mock:aggregated");
-]]></script>
-</div></div>And the same example using Spring XML:<div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="brush: xml; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[
-<camelContext xmlns="http://camel.apache.org/schema/spring">
- <route>
- <from uri="direct:start"/>
- <aggregate strategyRef="aggregatorStrategy" completionTimeoutCheckerInterval="10">
- <correlationExpression>
- <simple>header.id</simple>
- </correlationExpression>
- <completionTimeout>
- <header>timeout</header>
- </completionTimeout>
- <to uri="mock:aggregated"/>
- </aggregate>
- </route>
-</camelContext>
-
-<bean id="aggregatorStrategy" class="org.apache.camel.processor.BodyInAggregatingStrategy"/>
-]]></script>
-</div></div><strong>Note:</strong> You can also add a fixed timeout value and Camel will fallback to use this value if the dynamic value was <code>null</code> or <code>0</code>.<h4 id="Aggregator2-UsingdynamiccompletionSize">Using dynamic completionSize</h4><p>In this example we want to aggregate all incoming messages based on a dynamic size per correlation key. The size is computed at runtime based on the <code>mySize</code> header in the incoming messages. This is done using the <code>completionSize</code> option as shown:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[
-from("direct:start")
- // aggregate all exchanges correlated by the id header.
- // Aggregate them using the BodyInAggregatingStrategy strategy which
- // and the header mySize determines the number of aggregated messages should trigger the completion
- // and send it to mock:aggregated
- .aggregate(header("id"), new BodyInAggregatingStrategy()).completionSize(header("mySize"))
- .to("mock:aggregated");
-]]></script>
-</div></div>And the same example using Spring XML:<div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="brush: xml; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[
-<camelContext xmlns="http://camel.apache.org/schema/spring">
- <route>
- <from uri="direct:start"/>
- <aggregate strategyRef="aggregatorStrategy">
- <correlationExpression>
- <simple>header.id</simple>
- </correlationExpression>
- <completionSize>
- <header>mySize</header>
- </completionSize>
- <to uri="mock:aggregated"/>
- </aggregate>
- </route>
-</camelContext>
-
-<bean id="aggregatorStrategy" class="org.apache.camel.processor.BodyInAggregatingStrategy"/>
-]]></script>
-</div></div><strong>Note:</strong> You can also add a fixed size value and Camel will fallback to use this value if the dynamic value was <code>null</code> or <code>0</code>.<p></p><h4 id="Aggregator2-UsingThisPattern">Using This Pattern</h4>
-
-<p>If you would like to use this EIP Pattern then please read the <a shape="rect" href="getting-started.html">Getting Started</a>, you may also find the <a shape="rect" href="architecture.html">Architecture</a> useful particularly the description of <a shape="rect" href="endpoint.html">Endpoint</a> and <a shape="rect" href="uris.html">URIs</a>. Then you could try out some of the <a shape="rect" href="examples.html">Examples</a> first before trying this pattern out.</p><h4 id="Aggregator2-CompletingcurrentgroupdecidedfromtheAggregationStrategy">Completing current group decided from the AggregationStrategy</h4><p><strong>Available as of Camel 2.15</strong></p><p>The <code>AggregationStrategy</code> can now included a property on the returned <code>Exchange</code> that contains a boolean to indicate if the current group should be completed. This allows to overrule any existing completion predicates / sizes / timeouts etc, and complete the group.</p><p>For example the followin
g logic (from an unit test) will complete the group if the message body size is larger than 5. This is done by setting the property <span style="line-height: 1.4285715;">Exchange.AGGREGATION_COMPLETE_CURRENT_GROUP to true.</span></p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[ public final class MyCompletionStrategy implements AggregationStrategy {
+ boolean preComplete(Exchange oldExchange, Exchange newExchange);</plain-text-body><p>If the preComplete method returns true, then the existing groups is completed (without aggregating the incoming exchange (newExchange). And then the newExchange is used to start the correlation group from scratch so the group would contain only that new incoming exchange. This is known as pre-completion mode. And when the aggregation is in pre-completion mode, then only the following completions are in use</p><ul style="list-style-type: square;"><li>aggregationStrategy must implement <code>PreCompletionAwareAggregationStrategy</code> xxx</li><li>completionTimeout or completionInterval can also be used as fallback completions</li><li>any other completion are not used (such as by size, from batch consumer etc)</li><li>eagerCheckCompletion is implied as true, but the option has no effect</li></ul><h3 id="Aggregator2-PersistentAggregationRepository">Persistent AggregationRepository</h3><p>
The aggregator provides a pluggable repository which you can implement your own <code>org.apache.camel.spi.AggregationRepository</code>.<br clear="none"> If you need persistent repository then you can use either Camel <a shape="rect" href="hawtdb.html">HawtDB</a>, <a shape="rect" href="leveldb.html">LevelDB</a>, or <a shape="rect" href="sql-component.html">SQL Component</a> components.</p><h3 id="Aggregator2-Examples">Examples</h3><p>See some examples from the old <a shape="rect" href="aggregator.html">Aggregator</a> which is somewhat similar to this new aggregator.</p><parameter ac:name="title">Setting options in Spring XML</parameter><rich-text-body><p>Many of the options are configurable as attributes on the <code><aggregate></code> tag when using Spring XML.</p></rich-text-body><h4 id="Aggregator2-UsingcompletionTimeout">Using completionTimeout</h4><p>In this example we want to aggregate all incoming messages and after 3 seconds of inactivity we want the aggregation to com
plete. This is done using the <code>completionTimeout</code> option as shown:<plain-text-body>{snippet:id=e1|lang=java|url=camel/trunk/camel-core/src/test/java/org/apache/camel/processor/aggregator/AggregateSimpleTimeoutTest.java}</plain-text-body>And the same example using Spring XML:<plain-text-body>{snippet:id=e1|lang=xml|url=camel/trunk/components/camel-spring/src/test/resources/org/apache/camel/spring/processor/aggregator/SpringAggregateSimpleTimeoutTest.xml}</plain-text-body></p><h4 id="Aggregator2-UsingTimeoutAwareAggregationStrategy">Using TimeoutAwareAggregationStrategy</h4><p><strong>Available as of Camel 2.9.2</strong></p><p>If your aggregation strategy implements <code>TimeoutAwareAggregationStrategy</code>, then Camel will invoke the <code>timeout</code> method when the timeout occurs. Notice that the values for index and total parameters will be -1, and the timeout parameter will be provided only if configured as a fixed value. You must <strong>not</strong> throw any e
xceptions from the <code>timeout</code> method.</p><h4 id="Aggregator2-UsingCompletionAwareAggregationStrategy">Using CompletionAwareAggregationStrategy</h4><p><strong>Available as of Camel 2.9.3</strong></p><p>If your aggregation strategy implements <code>CompletionAwareAggregationStrategy</code>, then Camel will invoke the <code>onComplete</code> method when the aggregated Exchange is completed. This allows you to do any last minute custom logic such as to cleanup some resources, or additional work on the exchange as it's now completed.<br clear="none"> You must <strong>not</strong> throw any exceptions from the <code>onCompletion</code> method.</p><h4 id="Aggregator2-UsingcompletionSize">Using completionSize</h4><p>In this example we want to aggregate all incoming messages and when we have 3 messages aggregated (in the same correlation group) we want the aggregation to complete. This is done using the <code>completionSize</code> option as shown:<plain-text-body>{snippet:id=e1|lan
g=java|url=camel/trunk/camel-core/src/test/java/org/apache/camel/processor/aggregator/AggregateSimpleSizeTest.java}</plain-text-body>And the same example using Spring XML:<plain-text-body>{snippet:id=e1|lang=xml|url=camel/trunk/components/camel-spring/src/test/resources/org/apache/camel/spring/processor/aggregator/SpringAggregateSimpleSizeTest.xml}</plain-text-body></p><h4 id="Aggregator2-UsingcompletionPredicate">Using completionPredicate</h4><p>In this example we want to aggregate all incoming messages and use a <a shape="rect" href="predicate.html">Predicate</a> to determine when we are complete. The <a shape="rect" href="predicate.html">Predicate</a> can be evaluated using either the aggregated exchange (default) or the incoming exchange. We will give an example for both situations. We start with the default situation as shown:<plain-text-body>{snippet:id=e1|lang=java|url=camel/trunk/camel-core/src/test/java/org/apache/camel/processor/aggregator/AggregateSimplePredicateTest.java
}</plain-text-body>And the same example using Spring XML:<plain-text-body>{snippet:id=e1|lang=xml|url=camel/trunk/components/camel-spring/src/test/resources/org/apache/camel/spring/processor/aggregator/SpringAggregateSimplePredicateTest.xml}</plain-text-body>And the other situation where we use the <code>eagerCheckCompletion</code> option to tell Camel to use the incoming Exchange. Notice how we can just test in the completion predicate that the incoming message is the <em>END</em> message:<plain-text-body>{snippet:id=e1|lang=java|url=camel/trunk/camel-core/src/test/java/org/apache/camel/processor/aggregator/AggregateSimplePredicateEagerTest.java}</plain-text-body>And the same example using Spring XML:<plain-text-body>{snippet:id=e1|lang=xml|url=camel/trunk/components/camel-spring/src/test/resources/org/apache/camel/spring/processor/aggregator/SpringAggregateSimplePredicateEagerTest.xml}</plain-text-body></p><h4 id="Aggregator2-UsingdynamiccompletionTimeout">Using dynamic completion
Timeout</h4><p>In this example we want to aggregate all incoming messages and after a period of inactivity we want the aggregation to complete. The period should be computed at runtime based on the <code>timeout</code> header in the incoming messages. This is done using the <code>completionTimeout</code> option as shown:<plain-text-body>{snippet:id=e1|lang=java|url=camel/trunk/camel-core/src/test/java/org/apache/camel/processor/aggregator/AggregateExpressionTimeoutTest.java}</plain-text-body>And the same example using Spring XML:<plain-text-body>{snippet:id=e1|lang=xml|url=camel/trunk/components/camel-spring/src/test/resources/org/apache/camel/spring/processor/aggregator/SpringAggregateExpressionTimeoutTest.xml}</plain-text-body><strong>Note:</strong> You can also add a fixed timeout value and Camel will fallback to use this value if the dynamic value was <code>null</code> or <code>0</code>.</p><h4 id="Aggregator2-UsingdynamiccompletionSize">Using dynamic completionSize</h4><p>In th
is example we want to aggregate all incoming messages based on a dynamic size per correlation key. The size is computed at runtime based on the <code>mySize</code> header in the incoming messages. This is done using the <code>completionSize</code> option as shown:<plain-text-body>{snippet:id=e1|lang=java|url=camel/trunk/camel-core/src/test/java/org/apache/camel/processor/aggregator/AggregateExpressionSizeTest.java}</plain-text-body>And the same example using Spring XML:<plain-text-body>{snippet:id=e1|lang=xml|url=camel/trunk/components/camel-spring/src/test/resources/org/apache/camel/spring/processor/aggregator/SpringAggregateExpressionSizeTest.xml}</plain-text-body><strong>Note:</strong> You can also add a fixed size value and Camel will fallback to use this value if the dynamic value was <code>null</code> or <code>0</code>.</p><p><parameter ac:name=""><a shape="rect" href="using-this-pattern.html">Using This Pattern</a></parameter></p><h4 id="Aggregator2-Completingcurrentgroupdeci
dedfromtheAggregationStrategy">Completing current group decided from the AggregationStrategy</h4><p><strong>Available as of Camel 2.15</strong></p><p>The <code>AggregationStrategy</code> can now included a property on the returned <code>Exchange</code> that contains a boolean to indicate if the current group should be completed. This allows to overrule any existing completion predicates / sizes / timeouts etc, and complete the group.</p><p>For example the following logic (from an unit test) will complete the group if the message body size is larger than 5. This is done by setting the property <span style="line-height: 1.4285715;">Exchange.AGGREGATION_COMPLETE_CURRENT_GROUP to true.</span></p><plain-text-body> public final class MyCompletionStrategy implements AggregationStrategy {
@Override
public Exchange aggregate(Exchange oldExchange, Exchange newExchange) {
if (oldExchange == null) {
return newExchange;
}
- String body = oldExchange.getIn().getBody(String.class) + "+"
+ String body = oldExchange.getIn().getBody(String.class) + "+"
+ newExchange.getIn().getBody(String.class);
oldExchange.getIn().setBody(body);
if (body.length() >= 5) {
@@ -324,183 +130,125 @@ from("direct:start")
}
return oldExchange;
}
- }]]></script>
-</div></div><p> </p><h4 id="Aggregator2-ManuallyForcetheCompletionofAllAggregatedExchangesImmediately">Manually Force the Completion of All Aggregated Exchanges Immediately</h4><p><strong>Available as of Camel 2.9</strong><br clear="none"> You can manually trigger completion of all current aggregated exchanges by sending a message containing the header Exchange.AGGREGATION_COMPLETE_ALL_GROUPS set to true. The message is considered a signal message only, the message headers/contents will not be processed otherwise.</p><p><strong>Available as of Camel 2.11</strong><br clear="none"> You can alternatively set the header Exchange.AGGREGATION_COMPLETE_ALL_GROUPS_INCLUSIVE to true to trigger completion of all groups after processing the current message.</p><h4 id="Aggregator2-UsingaList<V>inAggregationStrategy">Using a List<V> in AggregationStrategy</h4><p><strong>Available as of Camel 2.11</strong></p><p>If you want to aggregate some value from the messages <V> into
a List<V> then we have added a <code>org.apache.camel.processor.aggregate.AbstractListAggregationStrategy</code> abstract class in <strong>Camel 2.11</strong> that makes this easier. The completed Exchange that is sent out of the aggregator will contain the List<V> in the message body.</p><p>For example to aggregate a List<Integer> you can extend this class as shown below, and implement the <code>getValue</code> method:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[
-/**
- * Our strategy just group a list of integers.
- */
-public final class MyListOfNumbersStrategy extends AbstractListAggregationStrategy<Integer> {
-
- @Override
- public Integer getValue(Exchange exchange) {
- // the message body contains a number, so just return that as-is
- return exchange.getIn().getBody(Integer.class);
- }
-}
-]]></script>
-</div></div><h3 id="Aggregator2-UsingAggregateController">Using AggregateController</h3><p><strong>Available as of Camel 2.16</strong></p><p>The <code>org.apache.camel.processor.aggregate.AggregateController</code> allows you to control the aggregate at runtime using Java or JMX API. This can be used to force completing groups of exchanges, or query its current runtime statistics.</p><p>The aggregator provides a default implementation if no custom have been configured, which can be accessed using <code>getAggregateController()</code> method. Though it may be easier to configure a controller in the route using aggregateController as shown below:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[private AggregateController controller = new DefaultAggregateController();
-Â
-from("direct:start")
- .aggregate(header("id"), new MyAggregationStrategy()).completionSize(10).id("myAggregator")
+ }</plain-text-body><p> </p><h4 id="Aggregator2-ManuallyForcetheCompletionofAllAggregatedExchangesImmediately">Manually Force the Completion of All Aggregated Exchanges Immediately</h4><p><strong>Available as of Camel 2.9</strong><br clear="none"> You can manually trigger completion of all current aggregated exchanges by sending a message containing the header Exchange.AGGREGATION_COMPLETE_ALL_GROUPS set to true. The message is considered a signal message only, the message headers/contents will not be processed otherwise.</p><p><strong>Available as of Camel 2.11</strong><br clear="none"> You can alternatively set the header Exchange.AGGREGATION_COMPLETE_ALL_GROUPS_INCLUSIVE to true to trigger completion of all groups after processing the current message.</p><h4 id="Aggregator2-UsingaList<V>inAggregationStrategy">Using a List<V> in AggregationStrategy</h4><p><strong>Available as of Camel 2.11</strong></p><p>If you want to aggregate some value from the messages <
;V> into a List<V> then we have added a <code>org.apache.camel.processor.aggregate.AbstractListAggregationStrategy</code> abstract class in <strong>Camel 2.11</strong> that makes this easier. The completed Exchange that is sent out of the aggregator will contain the List<V> in the message body.</p><p>For example to aggregate a List<Integer> you can extend this class as shown below, and implement the <code>getValue</code> method:<plain-text-body>{snippet:id=e1|lang=java|url=camel/trunk/camel-core/src/test/java/org/apache/camel/processor/aggregator/CustomListAggregationStrategyTest.java}</plain-text-body></p><h3 id="Aggregator2-UsingAggregateController">Using AggregateController</h3><p><strong>Available as of Camel 2.16</strong></p><p>The <code>org.apache.camel.processor.aggregate.AggregateController</code> allows you to control the aggregate at runtime using Java or JMX API. This can be used to force completing groups of exchanges, or query its current runti
me statistics.</p><p>The aggregator provides a default implementation if no custom have been configured, which can be accessed using <code>getAggregateController()</code> method. Though it may be easier to configure a controller in the route using aggregateController as shown below:</p><plain-text-body>private AggregateController controller = new DefaultAggregateController();
+ 
+from("direct:start")
+ .aggregate(header("id"), new MyAggregationStrategy()).completionSize(10).id("myAggregator")
.aggregateController(controller)
- .to("mock:aggregated");]]></script>
-</div></div><p>Then there is API on AggregateController to force completion. For example to complete a group with key foo</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[int groups = controller.forceCompletionOfGroup("foo");]]></script>
-</div></div><p>The number return would be the number of groups completed. In this case it would be 1 if the foo group existed and was completed. If foo does not exists then 0 is returned.</p><p>There is also an api to complete all groups</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[int groups = controller.forceCompletionOfAllGroups();]]></script>
-</div></div><p> </p><p>To configure this from XML DSL</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[<bean id="myController" class="org.apache.camel.processor.aggregate.DefaultAggregateController"/>
-Â
- <camelContext xmlns="http://camel.apache.org/schema/spring">
+ .to("mock:aggregated");</plain-text-body><p>Then there is API on AggregateController to force completion. For example to complete a group with key foo</p><plain-text-body>int groups = controller.forceCompletionOfGroup("foo");</plain-text-body><p>The number return would be the number of groups completed. In this case it would be 1 if the foo group existed and was completed. If foo does not exists then 0 is returned.</p><p>There is also an api to complete all groups</p><plain-text-body>int groups = controller.forceCompletionOfAllGroups();</plain-text-body><p> </p><p>To configure this from XML DSL</p><plain-text-body><bean id="myController" class="org.apache.camel.processor.aggregate.DefaultAggregateController"/>
+ 
+ <camelContext xmlns="http://camel.apache.org/schema/spring">
<route>
- <from uri="direct:start"/>
- <aggregate strategyRef="myAppender" completionSize="10" aggregateControllerRef="myController">
+ <from uri="direct:start"/>
+ <aggregate strategyRef="myAppender" completionSize="10" aggregateControllerRef="myController">
<correlationExpression>
<header>id</header>
</correlationExpression>
- <to uri="mock:result"/>
+ <to uri="mock:result"/>
</aggregate>
</route>
- </camelContext>]]></script>
-</div></div><p> </p><p>There is also JMX API on the aggregator which is available under the processors node in the Camel JMX tree.</p><p> </p><h3 id="Aggregator2-UsingGroupedExchanges">Using GroupedExchanges</h3><p>In the route below we group all the exchanges together using <code>groupExchanges()</code>:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[ from("direct:start")
+ </camelContext></plain-text-body><p> </p><p>There is also JMX API on the aggregator which is available under the processors node in the Camel JMX tree.</p><p> </p><h3 id="Aggregator2-UsingGroupedExchanges">Using GroupedExchanges</h3><p>In the route below we group all the exchanges together using <code>groupExchanges()</code>:</p><plain-text-body> from("direct:start")
// aggregate all using same expression
.aggregate(constant(true))
// wait for 0.5 seconds to aggregate
.completionTimeout(500L)
// group the exchanges so we get one single exchange containing all the others
.groupExchanges()
- .to("mock:result");
-]]></script>
-</div></div><p>As a result we have one outgoing <a shape="rect" href="exchange.html">Exchange</a> being routed the the "mock:result" endpoint. The exchange is a holder containing all the incoming Exchanges.<br clear="none"> To get access to these exchanges you need to access them from a property on the outgoing exchange as shown:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[List<Exchange> grouped = out.getProperty(Exchange.GROUPED_EXCHANGE, List.class);
-]]></script>
-</div></div><p>From <strong>Camel 2.13</strong> onwards this behavior has changed to store these exchanges directly on the message body which is more intuitive:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[List<Exchange> grouped = exchange.getIn().getBody(List.class);
-]]></script>
-</div></div><div class="confluence-information-macro confluence-information-macro-information"><span class="aui-icon aui-icon-small aui-iconfont-info confluence-information-macro-icon"></span><div class="confluence-information-macro-body"><p>Notice the old way using the property is still present in <strong>Camel 2.13</strong> onwards, but its considered deprecated and to be removed in Camel 3.0 onwards.</p></div></div><h3 id="Aggregator2-UsingPOJOsasAggregationStrategy">Using POJOs as AggregationStrategy</h3><p><strong>Available as of Camel 2.12</strong></p><div class="confluence-information-macro confluence-information-macro-tip"><span class="aui-icon aui-icon-small aui-iconfont-approve confluence-information-macro-icon"></span><div class="confluence-information-macro-body"><p>You can use POJOs as AggregationStrategy with the other <a shape="rect" href="eip.html">EIP</a>s that supports aggregation, such as <a shape="rect" href="splitter.html">Splitter</a>, <a shape="rect" href="rec
ipient-list.html">Recipient List</a>, etc.</p></div></div><p>To use the <code>AggregationStrategy</code> you had to implement the <code>org.apache.camel.processor.aggregate.AggregationStrategy</code> interface, which means your logic would be tied to the Camel API. From <strong>Camel 2.12</strong> onwards you can use a POJO for the logic and let Camel adapt to your POJO. To use a POJO a convention must be followed:</p><ul class="alternate"><li>there must be a public method to use</li><li>the method must not be void</li><li>the method can be static or non-static</li><li>the method must have 2 or more parameters</li><li>the parameters is paired so the first 50% is applied to the <code>oldExchange</code> and the reminder 50% is for the <code>newExchange</code></li><li>.. meaning that there must be an equal number of parameters, eg 2, 4, 6 etc.</li></ul><p>The paired methods is expected to be ordered as follows:</p><ul class="alternate"><li>the first parameter is the message body</li><l
i>the 2nd parameter is a Map of the headers</li><li>the 3rd parameter is a Map of the Exchange properties</li></ul><p>This convention is best explained with some examples.</p><p>In the method below, we have only 2 parameters, so the 1st parameter is the body of the <code>oldExchange</code>, and the 2nd is paired to the body of the <code>newExchange</code>:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[public String append(String existing, String next) {
+ .to("mock:result");
+</plain-text-body><p>As a result we have one outgoing <a shape="rect" href="exchange.html">Exchange</a> being routed the the "mock:result" endpoint. The exchange is a holder containing all the incoming Exchanges.<br clear="none"> To get access to these exchanges you need to access them from a property on the outgoing exchange as shown:</p><plain-text-body>List<Exchange> grouped = out.getProperty(Exchange.GROUPED_EXCHANGE, List.class);
+</plain-text-body><p>From <strong>Camel 2.13</strong> onwards this behavior has changed to store these exchanges directly on the message body which is more intuitive:</p><plain-text-body>List<Exchange> grouped = exchange.getIn().getBody(List.class);
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