初學：

需要用到的工具：dom4j.jar

讀取xml檔案:(匯入的都是org.w3c.dom下的包)

基於DocumentBuilderFactory

		DocumentBuilderFactory newInstance = DocumentBuilderFactory.newInstance();
		DocumentBuilder newDocumentBuilder = newInstance.newDocumentBuilder();
		Document parse = newDocumentBuilder.parse("src/person.xml");
		NodeList elementsByTagName = parse.getElementsByTagName("name");
		for(int i=0;i<elementsByTagName.getLength();i++){
			Node name1 = elementsByTagName.item(i);
			String names = name1.getTextContent();
			System.out.println(names);
		}
 

回寫xml檔案：

		Node item = parse.getElementsByTagName("person").item(0);
		Element createElement = parse.createElement("subject");
		Text createTextNode = parse.createTextNode("software engineering");
		createElement.appendChild(createTextNode);
		item.appendChild(createElement);
		TransformerFactory newInstance2 = TransformerFactory.newInstance();
		Transformer newTransformer = newInstance2.newTransformer();
		newTransformer.transform(new DOMSource(parse), new StreamResult("src/person.xml"));
 

基於TransformerFactory