JBossESB - JBossESBEIP - Content Based Routing

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Pattern Description

A Content Based Router inspects the content of a message and based on it's findings it can route the message to one or

more destinations. If none of the rules fires (no destinations found) then this will result in an error condition and the

message is routed to the Dead Letter Service.

Implementation

You can plug in other engines but by default we use JBossRules as our evaluation engine. JBossRules is deployed to the ESB by default in the jbrules.esb archive. You can use standard rules language or use an XPath construct to evaluate XML messages. To use XPath you need to reference the XPathLanguage.dsl.

Configuration

We have a standard action called: org.jboss.soa.esb.actions.ContentBasedRouter. The configuration of the action looks like:

...
<action class="org.jboss.soa.esb.actions.ContentBasedRouter" name="ContentBasedRouter">
    <property name="ruleSet" value="MyESBRules-XPath.drl"></property>
    <property name="ruleLanguage" value="XPathLanguage.dsl"></property>
    <property name="ruleReload" value="true"></property>
    <property name="destinations">
        <route-to destination-name="express" service-category="ExpressShipping" service-name="ExpressShippingService"></route-to>
        <route-to destination-name="normal" service-category="NormalShipping" service-name="NormalShippingService"></route-to>
    </property>
    <property name="object-paths">
        <object-path path="body.order" ></object-path>
        <object-path path="body.lineitem1"></object-path>
    </property> 
</action>
...

Note that JBossRules only deals with 'shallow' objects. So if in your rule you want to inspect an Order object which lives in the body of the message called "order", you will have specify adn object-path of "body.order".

More information

• Quickstarts:

• simple_cbr

• fun_cbr

• Content-Based Router config guide

• eip.com