Mule VM Endpoint

Question

Mule 3.3.1 CE

I'm probably going to kick myself, but what's going on with the following?

I have a private flow that takes in an XML payload and extracts a value among other things. This cut-down example works.

<flow name="MyFlow">
    <set-session-variable variableName="xyzMethod" value="#[xpath:local-name(/S:Envelope/S:Body/*[1])]"/>
</flow>

I want to put a VM inbound endpoint on this to solve some reuse issues. However, when I do, I get an exception on that xpath invocation. This exhibits the problem.

<flow name="MyFlow">
    <vm:inbound-endpoint exchange-pattern="request-response" path="execute.xyz"/>
    <set-session-variable variableName="dnbMethod" value="#[xpath:local-name(/S:Envelope/S:Body/*[1])]"/>
</flow>

I'm not seeing something obvious. What does the insertion of the VM endpoint do that is causing this?

Message               : There are two transformers that are an exact match for input: "class java.lang.String", output: "interface org.dom4j.Document". Transformers are: "XmlToDom4jDocument(class org.mule.module.xml.transformer.XmlToDomDocument)" and "XmlToDom4jDocument(class org.mule.module.xml.transformer.XmlToDomDocument)"
Code                  : MULE_ERROR-255

EDIT based upon discussion below

Based upon the discussion of trying MEL syntax, here are some results.

The input is (except for security info):

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:sch="http://applications.dnb.com/webservice/schema/">
<soapenv:Header>
</soapenv:Header>
<soapenv:Body>
  <sch:AdvancedCompanySearchRequest>
  </sch:AdvancedCompanySearchRequest>
</soapenv:Body>
</soapenv:Envelope>

The following is the exact code that executes successfully. I see AdvancedCompanySearchRequest in the console.

<flow name="ExecuteDandB" doc:name="ExecuteDandB">
<!--    <vm:inbound-endpoint exchange-pattern="request-response" path="execute.dnb" doc:name="DnB"/>-->

    <set-session-variable variableName="dnbMethod" value="#[xpath:local-name(/S:Envelope/S:Body/*[1])]"/>
<!--    <set-session-variable variableName="dnbMethod" value="#[xpath('/S:Envelope/S:Body/*[1]').name]"/>-->
    <logger level="INFO" message="#[sessionVars['dnbMethod']]"/>        
</flow>

The following is the exact code that fails to execute. I see the exception about two transformers described above.

    <flow name="ExecuteDandB" doc:name="ExecuteDandB">
<!--    <vm:inbound-endpoint exchange-pattern="request-response" path="execute.dnb" doc:name="DnB"/>-->

<!--    <set-session-variable variableName="dnbMethod" value="#[xpath:local-name(/S:Envelope/S:Body/*[1])]"/>-->
    <set-session-variable variableName="dnbMethod" value="#[xpath('/S:Envelope/S:Body/*[1]').name]"/>
    <logger level="INFO" message="#[sessionVars['dnbMethod']]"/>        
</flow>

Answer 1

You'll find the solution here:

http://forum.mulesoft.org/mulesoft/topics/no_idea_why_i_am_getting_this_error-csv8r

It's about having two copies of mule-module-xml.jar in your classpath.