Would this work?

  SOAPEnvelope soapEnvelope = MessageFactory.newInstance().createMessage().getSOAPPart().getEnvelope();
  SOAPBody soapBody = soapEnvelope.getBody();
  Name name = soapEnvelope.createName("HelloWorld", "hw", "");
  soapBody.addChildElement(name);.addTextNode( "hello text message" );