java – com. w3c. dom. Document does not have

I'm using the following code to create com. Com from string w3c. dom. Document：

DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder docBuilder = docFactory.newDocumentBuilder();
Document doc = docBuilder.parse(new InputSource(new StringReader("<a><b id="5"/></a>")));

When I system out. Println (xmltostring (document)), I get this:

<?xml version="1.0" encoding="UTF-8" standalone="no"?><a><b id="5"/></a>

Everything is OK, but I don't want XML to have Declaration, because I have to sign with my private key and embed it in the soap envelope

Solution

You can use the transformer and set outputkeys OMIT_ XML_ Setting the declaration property to "yes":

Transformer t = TransformerFactory.newInstance().newTransformer();
t.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION,"yes");
StringWriter sw = new StringWriter();
t.transform(new DOMSource(doc),new StreamResult(sw));

Note that you can also:

>If you don't need a document, use streamsource instead of domsource to provide the string directly to the converter. > If you want to output a document, use domresult instead of streamresult