调用
printdocument(doc, System.out)，该方法如下所示：
public static void printdocument(document doc, OutputStream out) throws IOException, TransformerException { TransformerFactory tf = TransformerFactory.newInstance(); Transformer transformer = tf.newTransformer(); transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "no"); transformer.setOutputProperty(OutputKeys.METHOD, "xml"); transformer.setOutputProperty(OutputKeys.INDENT, "yes"); transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8"); transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4"); transformer.transform(new DOMSource(doc), new StreamResult(new OutputStreamWriter(out, "UTF-8")));}（这
indent-amount是可选的，可能不适用于您的特定配置）
