MessageContext msgCtxOut = operationContext.getMessageContext(WSDLConstants.MESSAGE_LABEL_OUT_VALUE);
FileDataSource fileDataSource = new FileDataSource(name);
DataHandler dataHandler = new DataHandler(fileDataSource);
String contentID = "cid:" + msgCtxOut.addAttachment(dataHandler);
OMFactory factory = OMAbstractFactory.getOMFactory();
OMNamespace omNs = factory.createOMNamespace(namespace, "swa");
OMElement wrapperElement = factory.createOMElement("downloadFileResponse", omNs);
OMElement dataElement = factory.createOMElement("data", omNs, wrapperElement);