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Posted to commits@camel.apache.org by bu...@apache.org on 2015/07/13 12:20:36 UTC
svn commit: r958101 [2/2] - in /websites/production/camel/content:
book-in-one-page.html book-pattern-appendix.html cache/main.pageCache
content-enricher.html
Modified: websites/production/camel/content/content-enricher.html
==============================================================================
--- websites/production/camel/content/content-enricher.html (original)
+++ websites/production/camel/content/content-enricher.html Mon Jul 13 10:20:36 2015
@@ -120,7 +120,7 @@ from("direct:start").process(n
<to uri="activemq:Output"/>
</route>
]]></script>
-</div></div><p><span class="confluence-anchor-link" id="ContentEnricher-enrich-dsl"></span></p><h3 id="ContentEnricher-ContentenrichmentusingtheenrichDSLelement">Content enrichment using the <code>enrich</code> DSL element</h3><p>Camel comes with two flavors of content enricher in the DSL</p><ul class="alternate"><li><code>enrich</code></li><li><code>pollEnrich</code></li></ul><p><code>enrich</code> uses a <code>Producer</code> to obtain the additional data. It is usually used for <a shape="rect" href="request-reply.html">Request Reply</a> messaging, for instance to invoke an external web service.<br clear="none"> <code>pollEnrich</code> on the other hand uses a <a shape="rect" href="polling-consumer.html">Polling Consumer</a> to obtain the additional data. It is usually used for <a shape="rect" href="event-message.html">Event Message</a> messaging, for instance to read a file or download a <a shape="rect" href="ftp2.html">FTP</a> file.</p><div class="confluence-information-macro co
nfluence-information-macro-warning"><p class="title">Data from current Exchange not used</p><span class="aui-icon aui-icon-small aui-iconfont-error confluence-information-macro-icon"></span><div class="confluence-information-macro-body"><p><code>pollEnrich</code> or <code>enrich</code> does <strong>not</strong> access any data from the current <a shape="rect" href="exchange.html">Exchange</a> which means when polling it cannot use any of the existing headers you may have set on the <a shape="rect" href="exchange.html">Exchange</a>. For example you cannot set a filename in the <code>Exchange.FILE_NAME</code> header and use <code>pollEnrich</code> to consume only that file. For that you <strong>must</strong> set the filename in the endpoint URI.</p><p>Instead of using <code>enrich</code> you can use <a shape="rect" href="recipient-list.html">Recipient List</a> and have dynamic endpoints and define an <code>AggregationStrategy</code> on the <a shape="rect" href="recipient-list.html">Re
cipient List</a> which then would work as a <code>enrich</code> would do.</p><p>pollEnrich only accept one message as response. That means that if you target to enrich your original message with the enricher collecting messages from a seda, ... components using an aggregation strategy. Only one response message will be aggregated with the original message</p><p> </p></div></div><h3 id="ContentEnricher-EnrichOptions">Enrich Options</h3><div class="confluenceTableSmall"><div class="table-wrap"><table class="confluenceTable"><tbody><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Name</p></th><th colspan="1" rowspan="1" class="confluenceTh"><p>Default Value</p></th><th colspan="1" rowspan="1" class="confluenceTh"><p>Description</p></th></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>uri</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>The endpoint uri for the external ser
vice to enrich from. You must use either <code>uri</code> or <code>ref</code>.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>ref</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Refers to the endpoint for the external service to enrich from. You must use either <code>uri</code> or <code>ref</code>.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>strategyRef</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Refers to an <a shape="rect" class="external-link" href="http://camel.apache.org/maven/current/camel-core/apidocs/org/apache/camel/processor/aggregate/AggregationStrategy.html">AggregationStrategy</a> to be used to merge the reply from the external service, into a single outgoing message. By default Camel will use the reply from the external service as outgoin
g message. From <strong>Camel 2.12</strong> onwards you can also use a POJO as the <code>AggregationStrategy</code>, see the <a shape="rect" href="aggregator2.html">Aggregate</a> page for more details.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>strategyMethodName</code></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 the <a shape="rect" href="aggregator2.html">Aggregate</a> page for more details.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>strategyMethodAllowNull</code></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 aggrega
te method is not used if there was no data to enrich. If this option is <code>true</code> then <code>null</code> values is used as the <code>oldExchange</code> (when no data to enrich), when using POJOs as the <code>AggregationStrategy</code>. See the <a shape="rect" href="aggregator2.html">Aggregate</a> page for more details.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><code>aggregateOnException</code></td><td colspan="1" rowspan="1" class="confluenceTd"><code>false</code></td><td colspan="1" rowspan="1" class="confluenceTd"><strong>Camel 2.14:</strong> If this option is <code>false</code> then the aggregate method is <strong>not</strong> used if there was an exception thrown while trying to retrieve the data to enrich from the resource. Setting this option to <code>true</code> allows end users to control what to do if there was an exception in the <code>aggregate</code> method. For example to suppress the exception or set a custom message body etc.</td></tr><
tr><td colspan="1" rowspan="1" class="confluenceTd"><code>shareUnitOfWork</code></td><td colspan="1" rowspan="1" class="confluenceTd"><code>false</code></td><td colspan="1" rowspan="1" class="confluenceTd"><strong>Camel 2.16:</strong> <span style="color: rgb(0,0,0);"> Shares the unit of work with the parent and the resource exchange. Enrich will by default not share unit of work between the parent exchange and the resource exchange. This means the resource exchange has its own individual unit of work. See <a shape="rect" href="splitter.html">Splitter</a> for more information and example.</span></td></tr></tbody></table></div></div><p><strong>Using the</strong> <strong><a shape="rect" href="fluent-builders.html">Fluent Builders</a></strong></p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+</div></div><p><span class="confluence-anchor-link" id="ContentEnricher-enrich-dsl"></span></p><h3 id="ContentEnricher-ContentenrichmentusingtheenrichDSLelement">Content enrichment using the <code>enrich</code> DSL element</h3><p>Camel comes with two flavors of content enricher in the DSL</p><ul class="alternate"><li><code>enrich</code></li><li><code>pollEnrich</code></li></ul><p><code>enrich</code> uses a <code>Producer</code> to obtain the additional data. It is usually used for <a shape="rect" href="request-reply.html">Request Reply</a> messaging, for instance to invoke an external web service.<br clear="none"> <code>pollEnrich</code> on the other hand uses a <a shape="rect" href="polling-consumer.html">Polling Consumer</a> to obtain the additional data. It is usually used for <a shape="rect" href="event-message.html">Event Message</a> messaging, for instance to read a file or download a <a shape="rect" href="ftp2.html">FTP</a> file.</p><div class="confluence-information-macro co
nfluence-information-macro-warning"><p class="title">Camel 2.15 or older - Data from current Exchange not used</p><span class="aui-icon aui-icon-small aui-iconfont-error confluence-information-macro-icon"></span><div class="confluence-information-macro-body"><p><code>pollEnrich</code> or <code>enrich</code> does <strong>not</strong> access any data from the current <a shape="rect" href="exchange.html">Exchange</a> which means when polling it cannot use any of the existing headers you may have set on the <a shape="rect" href="exchange.html">Exchange</a>. For example you cannot set a filename in the <code>Exchange.FILE_NAME</code> header and use <code>pollEnrich</code> to consume only that file. For that you <strong>must</strong> set the filename in the endpoint URI.</p><p>Instead of using <code>enrich</code> you can use <a shape="rect" href="recipient-list.html">Recipient List</a> and have dynamic endpoints and define an <code>AggregationStrategy</code> on the <a shape="rect" href="r
ecipient-list.html">Recipient List</a> which then would work as a <code>enrich</code> would do.</p><p>pollEnrich only accept one message as response. That means that if you target to enrich your original message with the enricher collecting messages from a seda, ... components using an aggregation strategy. Only one response message will be aggregated with the original message.</p><p>From <strong>Camel 2.16</strong> onwards both enrich and pollEnrich supports dynamic endpoints that uses an <a shape="rect" href="expression.html">Expression</a> to compute the uri, which allows to use data from the current <a shape="rect" href="exchange.html">Exchange</a>. In other words all what is told above no longer apply and it just works.</p></div></div><h3 id="ContentEnricher-EnrichOptions">Enrich Options</h3><div class="confluenceTableSmall"><div class="table-wrap"><table class="confluenceTable"><tbody><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Name</p></th><th colspan="1" rowspan=
"1" class="confluenceTh"><p>Default Value</p></th><th colspan="1" rowspan="1" class="confluenceTh"><p>Description</p></th></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>uri</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>The endpoint uri for the external service to enrich from. You must use either <code>uri</code> or <code>ref</code>. <strong>Important:</strong> From Camel 2.16 onwards, this option is removed, and you use an <a shape="rect" href="expression.html">Expression</a> to configure the uri, such as <a shape="rect" href="simple.html">Simple</a> or <a shape="rect" href="constant.html">Constant</a> or any other dynamic language that can compute the uri dynamically using values from the current <a shape="rect" href="exchange.html">Exchange</a>.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>ref</code></p></td><td colspan="1" rowspan="1" class="co
nfluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Refers to the endpoint for the external service to enrich from. You must use either <code>uri</code> or <code>ref</code>. <span> </span><strong>Important:</strong><span> From Camel 2.16 onwards, this option is removed, and you use an </span><a shape="rect" href="expression.html">Expression</a><span> to configure the uri, such as </span><a shape="rect" href="simple.html">Simple</a><span> or </span><a shape="rect" href="constant.html">Constant</a><span> or any other dynamic language that can compute the uri dynamically using values from the current </span><span> </span><a shape="rect" href="exchange.html">Exchange</a><span>.</span></p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd">expression</td><td colspan="1" rowspan="1" class="confluenceTd"> </td><td colspan="1" rowspan="1" class="confluenceTd"><strong>Camel 2.16:</strong> Mandatory. The<span> </span><a shape="rect"
href="expression.html">Expression</a><span> to configure the uri, such as </span><a shape="rect" href="simple.html">Simple</a><span> or </span><a shape="rect" href="constant.html">Constant</a><span> or any other dynamic language that can compute the uri dynamically using values from the current </span><span> </span><a shape="rect" href="exchange.html">Exchange</a><span>.</span></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>strategyRef</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Refers to an <a shape="rect" class="external-link" href="http://camel.apache.org/maven/current/camel-core/apidocs/org/apache/camel/processor/aggregate/AggregationStrategy.html">AggregationStrategy</a> to be used to merge the reply from the external service, into a single outgoing message. By default Camel will use the reply from the external service as outgoing message. From <strong>Camel 2
.12</strong> onwards you can also use a POJO as the <code>AggregationStrategy</code>, see the <a shape="rect" href="aggregator2.html">Aggregate</a> page for more details.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>strategyMethodName</code></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 the <a shape="rect" href="aggregator2.html">Aggregate</a> page for more details.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>strategyMethodAllowNull</code></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 if there
was no data to enrich. If this option is <code>true</code> then <code>null</code> values is used as the <code>oldExchange</code> (when no data to enrich), when using POJOs as the <code>AggregationStrategy</code>. See the <a shape="rect" href="aggregator2.html">Aggregate</a> page for more details.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><code>aggregateOnException</code></td><td colspan="1" rowspan="1" class="confluenceTd"><code>false</code></td><td colspan="1" rowspan="1" class="confluenceTd"><strong>Camel 2.14:</strong> If this option is <code>false</code> then the aggregate method is <strong>not</strong> used if there was an exception thrown while trying to retrieve the data to enrich from the resource. Setting this option to <code>true</code> allows end users to control what to do if there was an exception in the <code>aggregate</code> method. For example to suppress the exception or set a custom message body etc.</td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><code>shareUnitOfWork</code></td><td colspan="1" rowspan="1" class="confluenceTd"><code>false</code></td><td colspan="1" rowspan="1" class="confluenceTd"><strong>Camel 2.16:</strong> <span style="color: rgb(0,0,0);"> Shares the unit of work with the parent and the resource exchange. Enrich will by default not share unit of work between the parent exchange and the resource exchange. This means the resource exchange has its own individual unit of work. See <a shape="rect" href="splitter.html">Splitter</a> for more information and example.</span></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><code>cacheSize</code></td><td colspan="1" rowspan="1" class="confluenceTd"> </td><td colspan="1" rowspan="1" class="confluenceTd"><strong>Camel 2.16:</strong> <span style="color: rgb(0,0,0);">Allows to configure the cache size for the </span><code>ProducerCache</code><span style="color: rgb(0,0,0);"> which caches producers for reuse in the e
nrich. Will by default use the default cache size which is 1000. Setting the value to -1 allows to turn off the cache all together.</span></td></tr></tbody></table></div></div><p><strong>Using the</strong> <strong><a shape="rect" href="fluent-builders.html">Fluent Builders</a></strong></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[AggregationStrategy aggregationStrategy = ...
from("direct:start")
@@ -174,7 +174,7 @@ from("direct:resource")
<to uri="direct:result"/>
</route>
]]></script>
-</div></div><h3 id="ContentEnricher-ContentenrichmentusingpollEnrich">Content enrichment using <code>pollEnrich</code></h3><p>The <code>pollEnrich</code> works just as the <code>enrich</code> however as it uses a <a shape="rect" href="polling-consumer.html">Polling Consumer</a> we have 3 methods when polling</p><ul class="alternate"><li>receive</li><li>receiveNoWait</li><li>receive(timeout)</li></ul><h3 id="ContentEnricher-PollEnrichOptions">PollEnrich Options</h3><div class="confluenceTableSmall"><div class="table-wrap"><table class="confluenceTable"><tbody><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Name</p></th><th colspan="1" rowspan="1" class="confluenceTh"><p>Default Value</p></th><th colspan="1" rowspan="1" class="confluenceTh"><p>Description</p></th></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>uri</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>The endpoint
uri for the external service to enrich from. You must use either <code>uri</code> or <code>ref</code>.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>ref</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Refers to the endpoint for the external service to enrich from. You must use either <code>uri</code> or <code>ref</code>.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>strategyRef</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Refers to an <a shape="rect" class="external-link" href="http://camel.apache.org/maven/current/camel-core/apidocs/org/apache/camel/processor/aggregate/AggregationStrategy.html">AggregationStrategy</a> to be used to merge the reply from the external service, into a single outgoing message. By default Camel will use the reply from the ex
ternal service as outgoing message. From <strong>Camel 2.12</strong> onwards you can also use a POJO as the <code>AggregationStrategy</code>, see the <a shape="rect" href="aggregator2.html">Aggregate</a> page for more details.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>strategyMethodName</code></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 the <a shape="rect" href="aggregator2.html">Aggregate</a> page for more details.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>strategyMethodAllowNull</code></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>fals
e</code> then the aggregate method is not used if there was no data to enrich. If this option is <code>true</code> then <code>null</code> values is used as the <code>oldExchange</code> (when no data to enrich), when using POJOs as the <code>AggregationStrategy</code>. See the <a shape="rect" href="aggregator2.html">Aggregate</a> page for more details.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>timeout</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><code>-1</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Timeout in millis when polling from the external service. See below for important details about the timeout.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><code>aggregateOnException</code></td><td colspan="1" rowspan="1" class="confluenceTd"><code>false</code></td><td colspan="1" rowspan="1" class="confluenceTd"><strong>Camel 2.14:</strong> If this option is <code>false</code> then the aggregat
e method is <strong>not</strong> used if there was an exception thrown while trying to retrieve the data to enrich from the resource. Setting this option to <code>true</code> allows end users to control what to do if there was an exception in the <code>aggregate</code> method. For example to suppress the exception or set a custom message body etc.</td></tr></tbody></table></div></div><div class="confluence-information-macro confluence-information-macro-information"><p class="title">Good practice to use timeout value</p><span class="aui-icon aui-icon-small aui-iconfont-info confluence-information-macro-icon"></span><div class="confluence-information-macro-body"><p>By default Camel will use the <code>receive</code>. Which may block until there is a message available. It is therefore recommended to always provide a timeout value, to make this clear that we may wait for a message, until the timeout is hit.</p></div></div><p>If there is no data then the <code>newExchange</code> in the ag
gregation strategy is <code>null</code>.</p><p>You can pass in a timeout value that determines which method to use</p><ul class="alternate"><li>if timeout is -1 or other negative number then <code>receive</code> is selected (<strong>Important:</strong> the <code>receive</code> method may block if there is no message)</li><li>if timeout is 0 then <code>receiveNoWait</code> is selected</li><li>otherwise <code>receive(timeout)</code> is selected</li></ul><p>The timeout values is in millis.</p><div class="confluence-information-macro confluence-information-macro-warning"><p class="title">Data from current Exchange not used</p><span class="aui-icon aui-icon-small aui-iconfont-error confluence-information-macro-icon"></span><div class="confluence-information-macro-body"><p><code>pollEnrich</code> does <strong>not</strong> access any data from the current <a shape="rect" href="exchange.html">Exchange</a> which means when polling it cannot use any of the existing headers you may have set on
the <a shape="rect" href="exchange.html">Exchange</a>. For example you cannot set a filename in the <code>Exchange.FILE_NAME</code> header and use <code>pollEnrich</code> to consume only that file. For that you <strong>must</strong> set the filename in the endpoint URI.</p></div></div><h4 id="ContentEnricher-Example">Example</h4><p>In this example we enrich the message by loading the content from the file named inbox/data.txt.</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+</div></div><h3 id="ContentEnricher-ContentenrichmentusingpollEnrich">Content enrichment using <code>pollEnrich</code></h3><p>The <code>pollEnrich</code> works just as the <code>enrich</code> however as it uses a <a shape="rect" href="polling-consumer.html">Polling Consumer</a> we have 3 methods when polling</p><ul class="alternate"><li>receive</li><li>receiveNoWait</li><li>receive(timeout)</li></ul><h3 id="ContentEnricher-PollEnrichOptions">PollEnrich Options</h3><div class="confluenceTableSmall"><div class="table-wrap"><table class="confluenceTable"><tbody><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Name</p></th><th colspan="1" rowspan="1" class="confluenceTh"><p>Default Value</p></th><th colspan="1" rowspan="1" class="confluenceTh"><p>Description</p></th></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>uri</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>The endpoint
uri for the external service to enrich from. You must use either <code>uri</code> or <code>ref</code>. <strong>Important:</strong><span> From Camel 2.16 onwards, this option is removed, and you use an </span><a shape="rect" href="expression.html">Expression</a><span> to configure the uri, such as </span><a shape="rect" href="simple.html">Simple</a><span> or </span><a shape="rect" href="constant.html">Constant</a><span> or any other dynamic language that can compute the uri dynamically using values from the current </span><span> </span><a shape="rect" href="exchange.html">Exchange</a><span>.</span></p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>ref</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Refers to the endpoint for the external service to enrich from. You must use either <code>uri</code> or <code>ref</code>. <strong>Important:</strong><span> From Camel 2.16 o
nwards, this option is removed, and you use an </span><a shape="rect" href="expression.html">Expression</a><span> to configure the uri, such as </span><a shape="rect" href="simple.html">Simple</a><span> or </span><a shape="rect" href="constant.html">Constant</a><span> or any other dynamic language that can compute the uri dynamically using values from the current </span><span> </span><a shape="rect" href="exchange.html">Exchange</a><span>.</span></p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><code>expression</code></td><td colspan="1" rowspan="1" class="confluenceTd"> </td><td colspan="1" rowspan="1" class="confluenceTd"><strong>Camel 2.16:</strong><span> Mandatory. The</span><span> </span><a shape="rect" href="expression.html">Expression</a><span> to configure the uri, such as </span><a shape="rect" href="simple.html">Simple</a><span> or </span><a shape="rect" href="constant.html">Constant</a><span> or any other dynamic language that can compute t
he uri dynamically using values from the current </span><span> </span><a shape="rect" href="exchange.html">Exchange</a><span>.</span></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>strategyRef</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Refers to an <a shape="rect" class="external-link" href="http://camel.apache.org/maven/current/camel-core/apidocs/org/apache/camel/processor/aggregate/AggregationStrategy.html">AggregationStrategy</a> to be used to merge the reply from the external service, into a single outgoing message. By default Camel will use the reply from the external service as outgoing message. From <strong>Camel 2.12</strong> onwards you can also use a POJO as the <code>AggregationStrategy</code>, see the <a shape="rect" href="aggregator2.html">Aggregate</a> page for more details.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>st
rategyMethodName</code></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 the <a shape="rect" href="aggregator2.html">Aggregate</a> page for more details.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>strategyMethodAllowNull</code></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 if there was no data to enrich. If this option is <code>true</code> then <code>null</code> values is used as the <code>oldExchange</code> (when no data to enrich), when using POJOs as the <code>AggregationStrategy</code>. See the <a shape="rect" href="aggre
gator2.html">Aggregate</a> page for more details.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>timeout</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><code>-1</code></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Timeout in millis when polling from the external service. See below for important details about the timeout.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><code>aggregateOnException</code></td><td colspan="1" rowspan="1" class="confluenceTd"><code>false</code></td><td colspan="1" rowspan="1" class="confluenceTd"><strong>Camel 2.14:</strong> If this option is <code>false</code> then the aggregate method is <strong>not</strong> used if there was an exception thrown while trying to retrieve the data to enrich from the resource. Setting this option to <code>true</code> allows end users to control what to do if there was an exception in the <code>aggregate</code> method. For example to suppress th
e exception or set a custom message body etc.</td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><code>cacheSize</code></td><td colspan="1" rowspan="1" class="confluenceTd"> </td><td colspan="1" rowspan="1" class="confluenceTd"><strong>Camel 2.16:</strong> <span style="color: rgb(0,0,0);">Allows to configure the cache size for the </span><code>ConsumerCache</code><span style="color: rgb(0,0,0);"> which caches consumers for reuse in the pollEnrich. Will by default use the default cache size which is 1000. Setting the value to -1 allows to turn off the cache all together.</span></td></tr></tbody></table></div></div><div class="confluence-information-macro confluence-information-macro-information"><p class="title">Good practice to use timeout value</p><span class="aui-icon aui-icon-small aui-iconfont-info confluence-information-macro-icon"></span><div class="confluence-information-macro-body"><p>By default Camel will use the <code>receive</code>. Which may blo
ck until there is a message available. It is therefore recommended to always provide a timeout value, to make this clear that we may wait for a message, until the timeout is hit.</p></div></div><p>If there is no data then the <code>newExchange</code> in the aggregation strategy is <code>null</code>.</p><p>You can pass in a timeout value that determines which method to use</p><ul class="alternate"><li>if timeout is -1 or other negative number then <code>receive</code> is selected (<strong>Important:</strong> the <code>receive</code> method may block if there is no message)</li><li>if timeout is 0 then <code>receiveNoWait</code> is selected</li><li>otherwise <code>receive(timeout)</code> is selected</li></ul><p>The timeout values is in millis.</p><div class="confluence-information-macro confluence-information-macro-warning"><p class="title">Camel 2.15 or older - Data from current Exchange not used</p><span class="aui-icon aui-icon-small aui-iconfont-error confluence-information-macro-
icon"></span><div class="confluence-information-macro-body"><p><code>pollEnrich</code> does <strong>not</strong> access any data from the current <a shape="rect" href="exchange.html">Exchange</a> which means when polling it cannot use any of the existing headers you may have set on the <a shape="rect" href="exchange.html">Exchange</a>. For example you cannot set a filename in the <code>Exchange.FILE_NAME</code> header and use <code>pollEnrich</code> to consume only that file. For that you <strong>must</strong> set the filename in the endpoint URI.</p><p><span>From </span><strong>Camel 2.16</strong><span> onwards both enrich and pollEnrich supports dynamic endpoints that uses an </span><a shape="rect" href="expression.html">Expression</a><span> to compute the uri, which allows to use data from the current </span><a shape="rect" href="exchange.html">Exchange</a><span>. In other words all what is told above no longer apply and it just works.</span></p></div></div><h4 id="ContentEnriche
r-Example">Example</h4><p>In this example we enrich the message by loading the content from the file named inbox/data.txt.</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")
.pollEnrich("file:inbox?fileName=data.txt")
.to("direct:result");