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The following example shows how to create a Message Filter route consuming messages from an endpoint called queue:a, which if the Predicate is true will be dispatched to queue:b

Using the Fluent Builders Wiki Markup{snippet:id=e2|lang=java|url=camel/trunk/camel-core/src/test/java/org/apache/camel/builder/RouteBuilderTest.java}You can, of course, use many different Predicate languages such as XPath, XQuery, SQL or various Scripting Languages. Here is an XPath example Wiki Markup{snippet:id=example|lang=java|url=camel/trunk/camel-core/src/test/java/org/apache/camel/processor/XPathFilterTest.java}Here's another example of using a bean to define the filter behavior:

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Using the Spring XML Extensions Wiki Markup{snippet:id=example|lang=xml|url=camel/trunk/components/camel-spring/src/test/resources/org/apache/camel/spring/xml/buildSimpleRouteWithHeaderPredicate.xml}You can also use a method call expression (to call a method on a bean) in the Message Filter, as shown below:

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Ensure you put the endpoint you want to filter <to uri="seda:b"/> before the closing </filter> tag or the filter will not be applied. From Camel 2.8: omitting this will result in an error.

For further examples of this pattern in use you could look at the junit test case

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In the example below we do not want to route messages any further that has the word Bye in the message body. Notice how we prevent this in the when() predicate by using the .stop(). Wiki Markup{snippet:id=e1|lang=java|url=camel/trunk/camel-core/src/test/java/org/apache/camel/processor/RouteStopTest.java}

How To Determine If An  Exchange Was Filtered

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The property has the key Exchange.FILTER_MATCHED, which has the String value of CamelFilterMatched. Its value is a boolean indicating true or false. If the value is true then the Exchange was routed in the filter block. This property will be visible within the Message Filter block who's Predicate matches (value set to true), and to the steps immediately following the Message Filter with the value set based on the results of the last Message Filter Predicate evaluated. Include PageUsing This Pattern

Using This Pattern