How can I get SessionID from SOAP Header in MessageMapping

Question

Hello experts,
I've got a Abap Proxy --> PI --> WebService scenario. I do the call to the web service and it returns me the data and a SessionID in the SOAP header. I've got a message mapping for the response, and in this message mapping I need to get this sessionID because I have to use it later.
I have tried with a UDF with this code:
String headerField = "";
try
  String key="SessionID";
  java.util.Map map;
  // get runtime constant map
  map = container.getTransformationParameters();
  // get value of header field by using variable key
  headerField = (String) map.get(key);
catch(Exception e){}
if(headerField==null)
    headerField = "";
return headerField;
But it returns me nothing.
In sxmb_moni I can see the sessionID (see attached file), so It should be possible to access it.
How can I do to get this data????
Many thanks.

Answer 1

Thanks Indrajit.
I have found a solution. I have to use the option: Do Not Use SOAP Envelope in my communication channel.
But as I am using web services I have to create the SOAP Envelope in my mapping (in request and in response).
I have created 2 xslt mapping files: one for request and one for response. The xslt mapping for the request it is placed in second position in my operation mapping. This xslt maping just move the fields and add the soap envelope (header and body, and inside the body places the data from 1st mapping).
The response xslt mapping it is placed directly in my operation mapping (in response area). It transforms the SOAP response into my Message Type.
Here you can find my xslt for request (sessionID, in0, in1 and in2 are fields from my source message type):
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:template match="/">
    <SOAP:Envelope xmlns:SOAP="http://www.w3.org/2003/05/soap-envelope">
      <SOAP:Header>
     <ses:sessionIDHeader xmlns:ses="http://xml.apache.org/axis/session">
             <sessionID><xsl:value-of select="*/sessionID"/></sessionID>
         </ses:sessionIDHeader>
      </SOAP:Header>
      <SOAP:Body>
      <ser:invokeService xmlns:ser="http://www.w3.org/2003/05/soap-envelope">
         <in0><xsl:value-of select="*/in0"/></in0>
         <in1><xsl:value-of select="*/in1"/></in1>
         <in2><xsl:value-of select="*/in2"/></in2>
      </ser:invokeService>
      </SOAP:Body>
    </SOAP:Envelope>
  </xsl:template>
</xsl:stylesheet>
Here is xslt for response (invokeServiceReturn,sessionIDare fields from my target message type):
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:template match="/">
    <ns1:MT_invokeServiceResponse xmlns:ns1="http://saras.com/pi/creditoycaucion">
        <invokeServiceReturn><xsl:value-of select="/*/*/*/invokeServiceReturn"/></invokeServiceReturn>
        <sessionID><xsl:value-of select="*/*/*/sessionID"/></sessionID>
    </ns1:MT_invokeServiceResponse>
  </xsl:template>
</xsl:stylesheet>
Kind Regards.