public static void write() {
		boolean validate = false;
		try {
			SAXBuilder builder = new SAXBuilder(validate);
			InputStream in = TestJDom.class.getClassLoader()
					.getResourceAsStream("test.xml");
			Document doc = builder.build(in);
			// ȡڵ <university>
			Element root = doc.getRootElement();
			// ޸
			root.setAttribute("name", "tsu");
			// ɾ
			boolean isRemoved = root.removeChildren("college");
			System.err.println(isRemoved);
			// 
			Element newCollege = new Element("college");
			newCollege.setAttribute("name", "new_college");
			Element newClass = new Element("class");
			newClass.setAttribute("name", "ccccc");
			newCollege.addContent(newClass);
			root.addContent(newCollege);
			XMLOutputter out = new XMLOutputter();
			File file = new File("src/jdom-modify.xml");
			if (file.exists()) {
				file.delete();
			}
			file.createNewFile();
			FileOutputStream fos = new FileOutputStream(file);
			out.output(doc, fos);
		} catch (JDOMException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}