Dom4J操作xml文档

package com.fly.dom4j;

import java.io.File;
import java.io.FileOutputStream;
import java.io.OutputStreamWriter;
import java.util.List;

import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;
import org.junit.Test;

public class Demo1 {

	// 读取xml文档第二本书的书名
	@Test
	public void read() throws Exception {
		SAXReader reader = new SAXReader();
		Document document = reader.read(new File("src/book.xml"));
		// 得到根节点
		Element root = document.getRootElement();
		Element book = (Element) root.elements("书").get(1);
		String value = book.element("书名").getText();
		System.out.println(value);
	}

	// 读取xml文档第二本书的书名的属性
	@Test
	public void readAttr() throws Exception {
		SAXReader reader = new SAXReader();
		Document document = reader.read(new File("src/book.xml"));
		// 得到根节点
		Element root = document.getRootElement();
		Element book = (Element) root.elements("书").get(1);
		// String value = book.element("书名").attribute("name").getValue();
		String value = book.element("书名").attributeValue("name");
		System.out.println(value);
	}

	// 在第一本书上添加一个新的售价
	@Test
	public void add() throws Exception {
		SAXReader reader = new SAXReader();
		Document doc = reader.read(new File("src/book.xml"));
		// 得到根节点
		Element book = doc.getRootElement().element("书");
		book.addElement("售价").setText("209元");

		// 指定格式化输入器
		OutputFormat format = OutputFormat.createPrettyPrint();
		format.setEncoding("gb2312");

		// 写回 可能会因为编码问题出现乱码
		// XMLWriter writer = new XMLWriter(new FileWriter("src/book.xml"));
		XMLWriter writer = new XMLWriter(new OutputStreamWriter(
				new FileOutputStream("src/book.xml"), "gb2312"), format);
		writer.write(doc);
		writer.close();
	}

	// 在第一本书上添加一个新的售价
	@Test
	public void add1() throws Exception {
		SAXReader reader = new SAXReader();
		Document doc = reader.read(new File("src/book.xml"));
		// 得到根节点
		Element book = doc.getRootElement().element("书");
		book.addElement("售价").setText("209元");

		// 指定格式化输入器
		OutputFormat format = OutputFormat.createPrettyPrint();
		format.setEncoding("utf-8");

		// 写回 可能会因为编码问题出现乱码
		XMLWriter writer = new XMLWriter(new FileOutputStream("src/book.xml"),
				format);
		writer.write(doc);
		writer.close();
	}

	// 在第一本书指定位置添加一个新的售价 更改保存了所有node的list集合的顺序
	@Test
	public void add2() throws Exception {
		SAXReader reader = new SAXReader();
		Document doc = reader.read(new File("src/book.xml"));
		// 得到根节点
		Element book = doc.getRootElement().element("书");
		List list = book.elements(); // [书名,作者,售价]

		Element price = DocumentHelper.createElement("售价");
		price.setText("209元");

		list.add(2, price);

		// 指定格式化输入器
		OutputFormat format = OutputFormat.createPrettyPrint();
		format.setEncoding("utf-8");

		// 写回 可能会因为编码问题出现乱码
		XMLWriter writer = new XMLWriter(new FileOutputStream("src/book.xml"),
				format);
		writer.write(doc);
		writer.close();
	}

	// 删除添加的节点
	@Test
	public void delete() throws Exception {
		SAXReader reader = new SAXReader();
		Document doc = reader.read(new File("src/book.xml"));

		Element price = (Element) doc.getRootElement().element("书")
				.elements("售价").get(1);
		price.getParent().remove(price);

		// 指定格式化输入器
		OutputFormat format = OutputFormat.createPrettyPrint();
		format.setEncoding("utf-8");

		// 写回 可能会因为编码问题出现乱码
		XMLWriter writer = new XMLWriter(new FileOutputStream("src/book.xml"),
				format);
		writer.write(doc);
		writer.close();
	}

	//修改指定属性值
	@Test
	public void update() throws Exception {
		SAXReader reader = new SAXReader();
		Document doc = reader.read(new File("src/book.xml"));

		Element book = (Element) doc.getRootElement().elements("书").get(1);
		book.element("作者").setText("活活命");

		// 指定格式化输入器
		OutputFormat format = OutputFormat.createPrettyPrint();
		format.setEncoding("utf-8");

		// 写回 可能会因为编码问题出现乱码
		XMLWriter writer = new XMLWriter(new FileOutputStream("src/book.xml"),
				format);
		writer.write(doc);
		writer.close();
	}
}