解析 xml

public class XMLDemo {
	public void getAllUserNames(String fileName) {
		try {
			DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
			DocumentBuilder db = dbf.newDocumentBuilder();
			File file = new File(fileName);
			if (file.exists()) {
				Document doc = db.parse(file);
				Element docEle = doc.getDocumentElement();
				// Print root element of the document
				System.out.println("Root element of the document: "+ docEle.getNodeName());
				NodeList studentList = docEle.getElementsByTagName("student");
				// Print total student elements in document
				System.out.println("Total students: " + studentList.getLength());
				if (studentList != null && studentList.getLength() > 0) {
					for (int i = 0; i < studentList.getLength(); i++) {
						Node node = studentList.item(i);
						if (node.getNodeType() == Node.ELEMENT_NODE) {
							System.out.println("=====================");
							Element e = (Element) node;
							NodeList nodeList = e.getElementsByTagName("name");
							System.out.println("Name: "+ nodeList.item(0).getChildNodes().item(0).getNodeValue());
							nodeList = e.getElementsByTagName("grade");
							System.out.println("Grade: "+ nodeList.item(0).getChildNodes().item(0).getNodeValue());
							nodeList = e.getElementsByTagName("age");
							System.out.println("Age: "+ nodeList.item(0).getChildNodes().item(0).getNodeValue());
						}
					}
				} else {
					System.exit(1);
				}
			}else{
				System.out.println("xml 文件没有找到");
			}
		} catch (Exception e) {
			System.out.println(e);
		}
	}

	public static void main(String[] args) {
		XMLDemo parser = new XMLDemo();
		parser.getAllUserNames("d:\\NewFile.xml");
	}
}