Camel ErrorHandler useOriginalMessage Attribute

Question

I've been using Camel (currently version 2.12.2) for a little over a year now and have run into an interesting situation with one of my web applicaitons (a few hundred routes). To overcome this issue, I want to use a special ErrorHandler that returns the original body if an exception is thrown in specific enriched routes. Here is a little sample context I put together to illustrate what I want to happen:

 <?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:camel="http://camel.apache.org/schema/spring"
        xmlns:context="http://www.springframework.org/schema/context"
        xmlns:util="http://www.springframework.org/schema/util"
        xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
   http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
   http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd
   http://www.springframework.org/schema/util  http://www.springframework.org/schema/util/spring-util.xsd">

   <!-- use for enriched routes so they pass the original to the global onException if exception is encountered -->
   <camel:errorHandler id='enrichmentErrorHandler' type="DefaultErrorHandler" useOriginalMessage="true"/>

   <camel:endpoint camelContextId="TestErrorHandlerContext" id="TestServletEndpoint" uri="servlet:///order"/>

   <bean id="testEx" class="java.io.IOException"/>

   <camelContext id="TestErrorHandlerContext" xmlns="http://camel.apache.org/schema/spring" xmlns:oas="http://www.verizonwireless.com/oas" trace="true">

      <onException>
         <exception>java.io.IOException</exception>
         <handled><constant>true</constant></handled>
         <log message="logging"/>
      </onException>

      <route id="startRoute">
          <from uri="TestServletEndpoint"/>

         <choice>
           <when>
             <simple>${body} == 'hello'</simple>

            <setBody><constant>world</constant></setBody>
            <!-- use new body -->
            <throwException ref="testEx"/>
           </when>
           <otherwise>
            <enrich uri="direct:enrichRoute"/>
           </otherwise>
         </choice>
       </route>

       <route id="enrichRoute" errorHandlerRef="enrichmentErrorHandler">
          <from uri="direct:enrichRoute"/>
           <setBody><constant>somethingElse</constant></setBody>
           <!-- use original body -->
           <throwException ref="testEx"/>
       </route>

    </camelContext>  
</beans>

When I send 'hello', I get back 'world' -> expected

When I send 'something', I get back 'sometingElse' -> unexpected

My thought process tells me that the enrichRoute should use the original body in the since it is referencing the enrichmentErrorHandler. What about my expectation is incorrect?

I am aware that I can have route-level onException blocks to return the original body, but it would be cleaner if I could get the error handler reference working since I'd have to change about 40 or so route definitions.

Answer 1

I have come to the conclusion that a route-level onException clause or a doTry/doCatch is the only way to deal with exceptions behind an enricher.