JAXP解析xml文件

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<bookshelf>
    <book>
        <name bookname="thinkinjava">Think in Java</name>
        <author>Bruce Eckel</author>
        <price>95.00</price>
    </book>
    <book>
        <name>Effective Java</name>
        <author>Joshua Bloch</author>
        <price>52.00</price>
    </book>
</bookshelf>

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import java.io.FileOutputStream;
import java.io.IOException;

public class JaxpDemo {

    public static void main(String[] args) {

        // 创建工厂
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();

        try {
            // 得到dom解析器
            DocumentBuilder builder = factory.newDocumentBuilder();

            // 解析xml文档，得到Document对象
            Document document = builder.parse("day02/src/book.xml");

            // 对xml文档进行CRUD

            // 读
            NodeList nodeList = document.getElementsByTagName("name");
            for (int i = 0; i < nodeList.getLength(); i++) {
                Node node = nodeList.item(i);
                String content = node.getTextContent();
                System.out.println(content);
            }

            // 遍历xml节点TagName
            Node root = document.getElementsByTagName("bookshelf").item(0);
            list(root);

            // 获取标签属性的值
            Element bookname = (Element) document.getElementsByTagName("name").item(0);
            String value = bookname.getAttribute("bookname");
            System.out.println(value);

            // 增
            // 增加节点
            Element version = document.createElement("version");
            version.setTextContent("2");
            // 选择指定的插入节点位置
            Element price = (Element) document.getElementsByTagName("price").item(0);
            // 选择增加的节点
            Element book1 = (Element) document.getElementsByTagName("book").item(0);
            /*book1.appendChild(element);*/
            book1.insertBefore(version, price);

            // 标签增加属性
            Element book2 = (Element) document.getElementsByTagName("name").item(1);
            book2.setAttribute("bookname", "effectivejava");

            // 删
            Element price1 = (Element) document.getElementsByTagName("price").item(0);
            book1.removeChild(price1);
            /*price1.getParentNode().removeChild(price1);*/

　　　　　　　// 改
            Element author = (Element) document.getElementsByTagName("author").item(0);
            author.setTextContent("Bruce Eckel Jr.");

            // 更新到文件
            TransformerFactory transformerFactory = TransformerFactory.newInstance();
            Transformer transformer = transformerFactory.newTransformer();
            transformer.transform(new DOMSource(document), new StreamResult(new FileOutputStream("day02/src/book.xml")));

        } catch (ParserConfigurationException | SAXException | IOException | TransformerException e) {
            e.printStackTrace();
        }
    }

    public static void list(Node node) {
        if (node instanceof Element) {
            System.out.println(node.getNodeName());
        }

        NodeList childList = node.getChildNodes();
        for (int i = 0; i < childList.getLength(); i++) {
            Node child = childList.item(i);
            list(child);
        }
    }
}