To convert between XML and DOM in Java

DOM3 にては Load & Save 機能 有りて package org.w3c.dom.ls に これら 有り。

import org.w3c.dom.ls.*;

DOMImplementationRegistry registry = DOMImplementationRegistry.newInstance();
DOMImplementationLS ls = (DOMImplementationLS) registry.getDOMImplementation("LS 3.0");

やゝ 詳しく 書くに

DOMImplementationRegistry registry = DOMImplementationRegistry.newInstance();
DOMImplementation dom = registry.getDOMImplementation("+LS 3.0 +XPath 3.0");
DOMImplementationLS ls = (DOMImplementationLS) dom.getFeature("+LS", "3.0");

して
load すなはち XML → DOM は

LSInput lsInput = ls.createLSInput();
FileInputStream fis = new FileInputStream(path);
lsInput.setByteStream(fis);
lsInput.setEncoding("UTF-8");

LSParser lsParser = ls.createLSParser(DOMImplementationLS.MODE_SYNCHRONOUS, null);
Document document = lsParser.parse(lsInput);

save すなはち DOM → XML は

LSOutput lsOutput = ls.createLSOutput();
FileOutputStream fos = new FileOutputStream(path);
lsOutput.setByteStream(fos);
lsOutput.setEncoding("UTF-8");

LSSerializer lsSerializer = ls.createLSSerializer();
serializer.write(document, lsOutput);

LSSerializer は 次の 如く 飾り 得:

serializer.getDomConfig().setParameter("comments", false);
serializer.getDomConfig().setParameter("format-pretty-print", true);
serializer.getDomConfig().setParameter("xml-declaration", false);
...

---

ちなみに それ以前にては 次の ごとく しき。

DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setnamespaceAware(false);
factory.setValidating(false);
factory.setExpandEntityRefereces(true);
factory.setIgnoringElementContentWhitespace(true);
factory.setIgnoringComments(true);
DocumentBuilder builder = factory.newDocumentBuilder();
Document document = builder.parse(file);

Transformer transformer = TransformerFactory.newInstance().newTransformer();
transformer.setOutputProperty(OutputKeys.METHOD, "xml");
transformer.setOUtputProperty(OutputKeys.INDENT, "yes");
DOMSource source = new DOMSource(document);
StreamResult result = new StreamResult(outputStream);
transformer.transform(source, result);