book2.xml

<?

xml version="1.0" encoding="UTF-8"?>

<书架>

  <书>

    <书名>JAVA</书名>

    <作者>XXXXXX</作者>

    <售价>23333</售价>

  </书>

  <书>

    <书名>ANDROID</书名>

    <作者>XXXXXX</作者>

    <售价>23333</售价>

  </书>

</书架>

增删改查方法：

public class dom4j2 {

	public static void main(String[] args) throws Exception {

		// find();

		// add();

		// update();

		// del();

		// attr();

	}

	private static void attr() throws Exception {

		SAXReader reader = new SAXReader();

		Document document = reader.read("book2.xml");

		Element rootElement = document.getRootElement();

		Element bookEle = rootElement.element("书");

		bookEle.addAttribute("出版社", "xxxxxx");

		// 查询出版社

		String publish = bookEle.attributeValue("出版社");

		System.out.println(publish);

		// 删除出版社

		Attribute attr = bookEle.attribute("出版社");

		attr.getParent().remove(attr);

		XMLWriter writer = new XMLWriter(new FileOutputStream("book2.xml"),

				OutputFormat.createPrettyPrint());

		writer.write(document);

		writer.close();

	}

	private static void del() throws Exception {

		SAXReader reader = new SAXReader();

		Document document = reader.read("book2.xml");

		Element rootElement = document.getRootElement();

		Element price2Ele = rootElement.element("书").element("特价");

		price2Ele.getParent().remove(price2Ele);

		XMLWriter writer = new XMLWriter(new FileOutputStream("book2.xml"),

				OutputFormat.createPrettyPrint());

		writer.write(document);

		writer.close();

	}

	private static void update() throws Exception {

		SAXReader reader = new SAXReader();

		Document document = reader.read("book2.xml");

		Element rootElement = document.getRootElement();

		rootElement.element("书").element("特价").setText("50");

		XMLWriter writer = new XMLWriter(new FileOutputStream("book2.xml"),

				OutputFormat.createPrettyPrint());

		writer.write(document);

		writer.close();

	}

	public static void add() throws Exception {

		SAXReader reader = new SAXReader();

		Document document = reader.read("book2.xml");

		Element rootElement = document.getRootElement();

		// 创建 <特价>结点 设置标签体

		Element price2 = DocumentHelper.createElement("特价");

		price2.setText("23232");

		// 获取父节点 并挂载

		Element bookEle1 = rootElement.element("书");

		bookEle1.add(price2);

		// 将内存中的dom树写到xml文件里

		// 方法1

		// FileWriter fw = new FileWriter("book2.xml");

		// document.write(fw);

		// fw.flush();

		// fw.close();

		// 方法2

		XMLWriter writer = new XMLWriter(new FileOutputStream("book2.xml"),

				OutputFormat.createPrettyPrint());// 格式化xml文件

		writer.write(document);

		writer.close();

	}

	public static void find() throws Exception {

		SAXReader reader = new SAXReader();

		Document document = reader.read("book2.xml");

		Element rootElement = document.getRootElement();

		List<Element> elements = rootElement.elements();

		Element book2Ele = elements.get(1);

		System.out.println(book2Ele.element("书名").getText());

	}

}