学步园

public class StudentDaoImpl implements StudentDao {
	private String url = "src/student.xml";

	/*
	 * <student idcard="111" examid="222"> <name>张三</name>
	 * <location>长沙</location> <grade>89</grade> </student> "src/student.xml"
	 */
	/**
	 * 添加学生
	 * 
	 * @author luozehua
	 */
	public void addStu(Student stu) {
		try {
			// 得到文档对象
			Document document = XmlUtils.getDocument(url);
			// 创建Student标签
			Element student = new Element("student");
			// 设置Student接点的属性
			student.setAttribute("idcard", stu.getIdcard());
			student.setAttribute("examid", stu.getExamid());
			// 创建name标签
			Element name = new Element("name");
			// 设置文本值
			name.setText(stu.getName());
			// 创建location标签
			Element location = new Element("location");
			// 设置文本值
			location.setText(stu.getLocation());
			// 创建grade标签
			Element grade = new Element("grade");
			// 设置文本值
			grade.setText(stu.getGrade() + "");
			// 将接点挂到Student下
			student.addContent(name);
			student.addContent(location);
			student.addContent(grade);

			// 获得文档的根节点
			Element rootNode = document.getRootElement();
			// 将Student挂到根节点上
			rootNode.addContent(student);
			XMLOutputter outputter = new XMLOutputter();
			outputter.output(document, new FileOutputStream(new File(url)));
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
	}

	@SuppressWarnings("unchecked")
	public void delStu(String name) {
		Document document = null;
		try {
			document = XmlUtils.getDocument(url);
			Element rootElement = document.getRootElement();
			XPath path = XPath.newInstance("//exam/student");

			List<Element> studentList = path.selectNodes(rootElement);
			for (Element element : studentList) {
				String nameString = element.getChildText("name");
				System.out.println(element.getName());
				if (nameString.equalsIgnoreCase(name)) {
					element.getParentElement().removeContent(element);
				}
			}
			XMLOutputter outputter = new XMLOutputter();
			outputter.output(document, new FileOutputStream(new File(url)));
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	@SuppressWarnings("unchecked")
	public Student find(String examid) {
		Student student = null;
		try {
			Document document = XmlUtils.getDocument(url);
			Element rootElement = document.getRootElement();
			XPath path = XPath.newInstance("//exam/student");
			// 获得根节点下所有子节点，直接直接点
			List<Element> studengList = path.selectNodes(rootElement);
			for (Element element : studengList) {

				String examidstrStr = element.getAttributeValue("examid");
				if (examidstrStr.equals(examid)) {
					student = new Student();
					student.setExamid(element.getAttributeValue("examid"));
					student.setIdcard(element.getAttributeValue("idcard"));
					student.setName(element.getChildText("name"));
					student.setLocation(element.getChildText("location"));
					student.setGrade(Double.parseDouble(element.getChildText("grade")));
				}
			}
		} catch (JDOMException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
		return student;
	}
}