Java生成xml

documentBuilderFactory factory = documentBuilderFactory.newInstance();
documentBuilder db = factory.newdocumentBuilder();
document document = db.newdocument();
document.setXmlStandalone(false); // 去掉xml 的默认文件头

Element include = document.createElement("include");
Element gateway = document.createElement("gateway");
Element param = document.createElement("param");
Element param1 = document.createElement("param");
Element param2 = document.createElement("param");
Element param3 = document.createElement("param");
gateway.setAttribute("name",name);

gateway.setAttribute("name",sipGateway);
include.appendChild(gateway);
param.setAttribute("name","username");
param1.setAttribute("name","realm");
param2.setAttribute("name","proxy");
param3.setAttribute("name","register");
param.setAttribute("value",callNumber);
param1.setAttribute("value",realm);
param2.setAttribute("value",proxy);
param3.setAttribute("value",register);
gateway.appendChild(param);
gateway.appendChild(param1);
gateway.appendChild(param2);
gateway.appendChild(param3);
document.appendChild(include);

  // 创建TransformerFactory对象
            TransformerFactory tff = TransformerFactory.newInstance();
            // 创建 Transformer对象
            Transformer tf = tff.newTransformer();
            // 输出内容是否使用换行
            tf.setOutputProperty(OutputKeys.INDENT, "yes");
            //缩进2格
            tf.setOutputProperty(OutputPropertiesFactory.S_KEY_INDENT_AMOUNT, "2");
            tf.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION,"yes");
            StreamResult result = new StreamResult(out) ;
            tf.transform(new DOMSource(document.getdocumentElement()), new StreamResult(out));