code: protected String getSoapAction() {
          String soapAction = null;
          try {
              soapAction = getAttributeValueSmart(SOAP_ACTION);
          }
          catch (PropertyException ex) {
              logger.severeException(ex.getMessage(), ex);
          }
  
          if (soapAction == null) {
              // required by SOAP 1.1 (http://www.w3.org/TR/soap11/#_Toc478383528)
              String soapVersion = getSoapVersion();
              if (soapVersion != null && soapVersion.equals(SOAP_VERSION_11))
                  soapAction = "";
          }
  
          return soapAction;
      }
docs: The SOAPAction HTTP request header value.