JAXP-DOM：

DOM树：

使用DOM方式解析XML：

CUDTest.java：

<span style="font-size:14px;">package com.example.jaxp.dom;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public class CUDTest {
	public static void main(String[] args) throws Exception {
		/*
		 * 将内容进行修改：增，删，改
		 */
		// 读取document
		Document document = CUDTest.getDocument();
		add(document);
		update(document);
		remove(document);
		
	}

	private static void add(Document document) throws Exception {
		// 增：
		/*
		 * <book id="b002"> <title>Java in Thinking</title> <price>45</price>
		 * </book>
		 */
		// 获取根元素
		Element rootElement = document.getDocumentElement();
		// 创建book元素
		Element newBook = document.createElement("book");
		// 添加属性
		newBook.setAttribute("id","b003");
		// 添加元素
		Element title = document.createElement("title");
		title.setTextContent("编程思想");
		newBook.appendChild(title);
		// 将book元素添加进根元素中
		rootElement.appendChild(newBook);
		// 保存
		sava(document);
	}

	private static void remove(Document document) throws Exception {
		// 删：删除<book id="b001">
		// 获取所有的书籍
		NodeList bookList = document.getElementsByTagName("book");
		for (int i = 0; i < bookList.getLength(); i++) {
			// 获取一本书
			Node bookNode = bookList.item(i);
			// 获取属性
			Element bookElement = (Element) bookNode;
			String id = bookElement.getAttribute("id");
			// 判断id
			if (id.equals("b001")) {
				// 获取父节点
				Node parent = bookElement.getParentNode();
				// 从父节点删除子节点
				parent.removeChild(bookElement);
			}
		}
		// 保存
		sava(document);
	}

	private static void update(Document document) throws Exception {
		// 修改：修改<price>22</price> 为35
		// 获取所有的书籍
		NodeList bookList = document.getElementsByTagName("book");
		for (int i = 0; i < bookList.getLength(); i++) {
			// 获取一本书
			Node bookNode = bookList.item(i);
			// 获取属性
			Element bookElement = (Element) bookNode;
			String id = bookElement.getAttribute("id");
			// 判断id
			if (id.equals("b001")) {
				// 获取所有的title
				NodeList priceList = bookElement.getElementsByTagName("price");
				// 获取唯一的title
				Node price = priceList.item(0);
				// 修改：
				price.setTextContent("35");
			}
		}
		// 保存
		sava(document);
	}

	private static void sava(Document document) throws Exception {
		//保存
		// 获取持久化对象工厂实例
		TransformerFactory factory = TransformerFactory.newInstance();
		// 获取持久化
		Transformer transformer = factory.newTransformer();
		// 源：
		Source xmlSource = new DOMSource(document);
		// 结果：
		StreamResult outputTarget = new StreamResult("Book.jasp.xml");
		transformer.transform(xmlSource,outputTarget);
		System.out.println("done");
	}

	public static Document getDocument() throws Exception {
		//读
		// 获取解析器工厂实例
		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
		// 获取解析器
		DocumentBuilder builder = factory.newDocumentBuilder();
		// 获取document
		Document document = builder.parse("Book.xml");
		return document;
	}
}
</span>

<span style="font-size:14px;">package com.example.jaxp.dom;

import java.util.ArrayList;
import java.util.List;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import com.example.domain.Book;

public class DomTest {
	public static void main(String[] args) throws Exception {
		System.out.println(getAllBooks());
	}

	/*
	 * 获得所有的书籍，将所有的书籍内容保存list
	 */
	public static List<Book> getAllBooks() throws Exception {
		String title = "";
		String price = "";
		//创建list，用于保存所有的数据
		List<Book> bookList = new ArrayList<Book>();
		/*
		 * 从xml文档中将需求的数据，查询出来，替换模拟数据
		 */
		// 获得工厂实例
		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
		// 获得解析器
		DocumentBuilder builder = factory.newDocumentBuilder();
		// 获得document ----解析xml文件  路径问题会导致：java.io.FileNotFoundException
		Document document = builder.parse("Book.xml");
		// 获取元素
		NodeList bookElements = document.getElementsByTagName("book");
		// 遍历所有的书籍元素，获取元素属性
		for (int i = 0; i < bookElements.getLength(); i++) {
			Node node = bookElements.item(i);
			// 父类给子类
			Element bookEle = (Element) node;
			// 获取 元素属性 id
			String id = bookEle.getAttribute("id");
			//System.out.println(id);

			// 查询title和price
			// 获取当前节点（book元素）的所有子节点
			NodeList childList = bookEle.getChildNodes();
			// 遍历子节点
			for (int c = 0; c < childList.getLength(); c++) {
				// 获取所有的孩子
				Node childNode = childList.item(c);
				String childName = childNode.getNodeName();
				// 判断标签是否是title
				if ("title".equals(childName)) {
					// 获取title内容
					title = childNode.getTextContent();
				} else if ("price".equals(childName)) {
					// 获取price内容
					price = childNode.getTextContent();
				}
			}

			// 创建Javabean对象
			Book book = new Book();
			book.setId(id);
			book.setTitle(title);
			book.setPrice(price);

			bookList.add(book);
		}
		return bookList;
	}
}
</span>