Catch soap faults

Question

I have the following scenario: SAP ABAP proxy --> XI --> IIS web service.  The IIS web service is not in my hand.
At some request the server has internal server errors. In that case we get SOAP faults from the web service. Now we have the situation that such SOAP faults causes XI mapping errors.  But this is not good. I would like to transfer such faults as application faults to the calling ABAP proxy. But I don't know how I can catch these SOAP faults.
Here is the situation in detail.
The response from the IIS web service:
<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
     <soap:Body>
          <soap:Fault>
               <faultcode>soap:Server</faultcode>
               <faultstring>error description </faultstring>
               <faultactor>ws user account</faultactor>
               <detail>
                    <ServerExceptions>bla bla bla</ServerExceptions>
               </detail>
          </soap:Fault>
     </soap:Body>
</soap:Envelope>
In XI monitoring I have 3 entries: my call and two error messages.
First error message payload:
<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>
<!--  Aufruf eines Adapters  -->
  <ServerExceptions>blab la bla</ServerExceptions>
Error information:
<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>
<!--  Mapping der Response-Message  -->
<SAP:Error xmlns:SAP="http://sap.com/xi/XI/Message/30" xmlns:SOAP="http://schemas.xmlsoap.org/soap/envelope/" SOAP:mustUnderstand="1">
  <SAP:Category>Application</SAP:Category>
  <SAP:Code area="UNKNOWN">APPLICATION_ERROR</SAP:Code>
  <SAP:P1 />
  <SAP:P2 />
  <SAP:P3 />
  <SAP:P4 />
  <SAP:AdditionalText>application fault</SAP:AdditionalText>
  <SAP:ApplicationFaultMessage namespace="">ServerExceptions</SAP:ApplicationFaultMessage>
  <SAP:Stack />
  <SAP:Retry>M</SAP:Retry>
  </SAP:Error>
The second error message has the same payload but a different error part:
<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>
<!--  Mapping der Response-Message -->
<SAP:Error xmlns:SAP="http://sap.com/xi/XI/Message/30" xmlns:SOAP="http://schemas.xmlsoap.org/soap/envelope/" SOAP:mustUnderstand="1">
  <SAP:Category>XIServer</SAP:Category>
  <SAP:Code area="MAPPING">NO_MAPPINGPROGRAM_FOUND</SAP:Code>
  <SAP:P1>"my mapping program"</SAP:P1>
  <SAP:P2 />
  <SAP:P3 />
  <SAP:P4 />
  <SAP:AdditionalText />
  <SAP:ApplicationFaultMessage namespace="" />
  <SAP:Stack>Das Interface-Mapping "my mapping program" ist nicht im Laufzeit-Cache vorhanden.</SAP:Stack>
  <SAP:Retry>N</SAP:Retry>
  </SAP:Error>
Is there any opportunity to catch such SOAP faults or server errors? I would like to map them in the xi fault structure. So the calling ABAP proxy gets the error message. Now I get a XI error and always a mail because I use the alert framework. But this is no XI error and I don't want to get such error messages.

Answer 1

Hi Smitha.
Yes. I have a WSDL from the external web service but the WSDL doesn't contain any fault definition. But I know the fault structure because I catch such an exception with XML Spy SOAP Proxy. The Exception looks like in my first post. 
The problem is that I don't get this exception in my hands. When I use the Message Display Tool of the Runtime Workbench I can only see the <ServerExceptions> node of the exception in my payload. So I only can deal with this. So I have  specified a xsd for this.
<?xml version="1.0" encoding="ISO-8859-1"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified">
     <xs:element name="ServerExceptions">
          <xs:simpleType>
               <xs:restriction base="xs:string" />
          </xs:simpleType>
     </xs:element>
</xs:schema>
I load this as external definition and add this to my interface as fault type. After that I'm able to catch the exception and I get the content of this node and map this to the fault message of my outbound interface. Unfortunately the content of this node is useless. I need the values of the other nodes.
O course I tried your proposal and add the complete fault type definition to the given wsdl and after that I re-import this new wsdl. But that doesn't change the behaviour described above.
The key point is that I don't get the whole exception.