I would like to extract the return (currently false) value from the following XML:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
      <ns:isPumpOnResponse xmlns:ns="http://webservice.whatever">

Is there a way of getting it out of the SOAPMessage object?

SOAPMessage soapResponse = soapConnection.call(createSOAPRequest(webMethodName), url);


You have to parse the message, and find the <ns:return>...</ns:return> value (where the ... is). IE, this is the return value for the call. If this SOAP call returns more data that just a boolean true/false value, you need to do more work.