Here you can find the source of newDocument()
public static Document newDocument()
//package com.java2s; //License from project: Open Source License import org.w3c.dom.Document; import org.w3c.dom.Element; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.parsers.ParserConfigurationException; public class Main { public static Document newDocument() { try {/*from w w w .j a v a2 s .c om*/ DocumentBuilder builder = createDefaultDocumentBuilderFactory().newDocumentBuilder(); return builder.newDocument(); } catch (ParserConfigurationException e) { //not occur e.printStackTrace(); throw new IllegalStateException(e); } } public static Document newDocument(String nsuri, String qname) { Document doc = newDocument(); Element el = doc.createElementNS(nsuri, qname); if (nsuri != null) { int idx = qname.indexOf(':'); if (idx == -1) { el.setAttribute("xmlns", nsuri); } else { el.setAttribute("xmlns:" + qname.substring(0, idx), nsuri); } } doc.appendChild(el); return doc; } public static DocumentBuilder newDocumentBuilder(boolean ignoreWhitespace, boolean ignoreComment) { try { DocumentBuilderFactory dbf = createDefaultDocumentBuilderFactory(); dbf.setIgnoringElementContentWhitespace(ignoreWhitespace); dbf.setIgnoringComments(ignoreComment); return dbf.newDocumentBuilder(); } catch (ParserConfigurationException e) { //not occur e.printStackTrace(); throw new IllegalStateException(e); } } public static final DocumentBuilderFactory createDefaultDocumentBuilderFactory() { DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); dbf.setCoalescing(true); dbf.setExpandEntityReferences(true); dbf.setIgnoringComments(true); dbf.setIgnoringElementContentWhitespace(true); dbf.setNamespaceAware(true); dbf.setValidating(false); dbf.setXIncludeAware(true); return dbf; } }