XML PArsing出现“ [#document：null]”问题

Question

after having a good look online, I am struggling with this one. Basically, I call an API, it returns XML, this xml requires to be updated, then sent back to the api. The code I currently have is :

public string update(){

String url = GeneralProps.getProperty("XMLUpdateURL")+testCaseID+"/block/include/data/no";
ArrayList<String> tempArray =  HttpHelper.sendAuthGetRequest(url, GeneralProps.getProperty("Username"), GeneralProps.getProperty("Password"));

        Document doc = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new InputSource(new StringReader(tempArray.get(1).toString())));

    XPathExpression expr = xpath.compile("//Step["+ stepNo + "]/"+ nodeName         +"/text()");
        Object result = expr.evaluate(doc, XPathConstants.NODESET);
        NodeList nodes = (NodeList) result;
        for (int i = 0; i < nodes.getLength(); i++) {
            System.out.println(nodes.item(i).getNodeValue());
            nodes.item(i).setNodeValue(newNodeValue);
            System.out.println(nodes.item(i).getNodeValue());

        }

    return doc;

    }

However, doc returns [#document: null] - which means the document is actually there, I can make the amendments, but I cannot seem to get the xml from the doc as this is required to bepassed into another method to upload the xml to the API, but i cannot figure out how!!

Answer 1

I figured this out....

using the below code:

Transformer transformer = TransformerFactory.newInstance().newTransformer();
        transformer.setOutputProperty(OutputKeys.INDENT, "yes");
        StreamResult sResult = new StreamResult(new StringWriter());
        DOMSource source = new DOMSource(doc);
        transformer.transform(source, sResult);
        String xmlString = sResult.getWriter().toString();      

        return xmlString;

I was able to transform the contents to a string and upload the string as I required...