Dom4j操作XML文档

<?xml version="1.0" encoding="UTF-8"?>
<书架> 
  <书> 
    <书名 name="aaa">java开发</书名>  
    <作者>小明</作者>  
    <售价>108元</售价>
    
  </书>  
  <书>
    <书名>Android</书名> 
    <作者>张三</作者>  
    <售价>85元</售价> 
  </书> 
</书架>

package cn.lsl.dom4j;

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

import org.dom4j.Document;
import org.dom4j.DocumentException;
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 Demo {
	//遍历xml文档所有标签
	@Test
	public void listFile() throws Exception{
		SAXReader reader = new SAXReader();
		//解析文档，得到代表文档的Document
		Document document = reader.read(new File("src/book.xml"));
		Element root = document.getRootElement();
		list(root);
	}
	
	public void list(Element e){
		System.out.println(e.getName());
		List<Element> list = e.elements();
		for(Element child : list){
			list(child);
		}
	}
	
	//获取节点内容
	@Test
	public void test1() throws Exception{
		SAXReader reader = new SAXReader();
		Document document = reader.read(new File("src/book.xml"));
		String value = document.getRootElement().element("书").element("书名").getText();
		System.out.println(value);
	}
	
	//获取节点属性
	@Test
	public void test2() throws Exception{
		SAXReader reader = new SAXReader();
		Document document = reader.read(new File("src/book.xml"));
		Element bookname = document.getRootElement().element("书").element("书名");
		System.out.println(bookname.attributeValue("name"));
	}
	
	//添加一个节点
	@Test
	public void test3() throws Exception{
		SAXReader reader = new SAXReader();
		Document document = reader.read(new File("src/book.xml"));
		//创建要添加的节点
		Element e  = DocumentHelper.createElement("售价");
		e.setText("59元");
		//挂节点
		document.getRootElement().element("书").add(e);
		//把更新的 内容写到xml中

//方法一：有可能出现乱码		
//		XMLWriter writer = new XMLWriter(new FileWriter("src/book.xml"));
//		writer.write(document);
//		writer.close();
		
//方法二
//		XMLWriter writer = new XMLWriter(new OutputStreamWriter(new FileOutputStream("src/book.xml"),"UTF-8"));
//		writer.write(document);
//		writer.close();
		
		//方法三，一般推荐这种方法
		OutputFormat format = OutputFormat.createPrettyPrint();	//格式输出器,创建格式良好的输出
		format.setEncoding("UTF-8");
		XMLWriter writer = new XMLWriter(new FileOutputStream("src/book.xml"),format);
		writer.write(document);
		writer.close();
	}
	
	//添加节点方法二
	@Test
	public void test4() throws Exception{
		SAXReader reader = new SAXReader();
		Document document = reader.read(new File("src/book.xml"));
		document.getRootElement().element("书").addElement("售价").setText("18元");
		OutputFormat format = OutputFormat.createPrettyPrint();
		format.setEncoding("UTF-8");
		XMLWriter writer = new XMLWriter(new FileOutputStream("src/book.xml"),format);
		writer.write(document);
		writer.close();
	}
	
	//向指定位置添加节点
	@Test
	public void test5() throws Exception{
		SAXReader reader = new SAXReader();
		Document document = reader.read(new File("src/book.xml"));
		//创建要添加的节点
		Element e = DocumentHelper.createElement("售价");
		e.setText("108元");
		
		List list = document.getRootElement().element("书").elements();
		list.add(2, e);
		
		OutputFormat format = OutputFormat.createPrettyPrint();
		format.setEncoding("UTF-8");
		XMLWriter writer = new XMLWriter(new FileOutputStream("src/book.xml"));
		writer.write(document);
		writer.close();
	}
	
	//删除节点
	@Test
	public void test6() throws Exception{
		SAXReader reader = new SAXReader();
		Document document = reader.read(new File("src/book.xml"));
		
		Element e = (Element)document.getRootElement().element("书").elements("售价").get(1);	//指定未指定位置的售价节点
		e.getParent().remove(e);
		
		OutputFormat format = OutputFormat.createPrettyPrint();
		format.setEncoding("UTF-8");
		XMLWriter writer = new XMLWriter(new FileOutputStream("src/book.xml"));
		writer.write(document);
		writer.close();
		
	}
	
	//修改节点，修改第二本书的值
	@Test
	public void test7() throws Exception{
		SAXReader reader = new SAXReader();
		Document document = reader.read(new File("src/book.xml"));
		
		Element e = (Element)document.getRootElement().elements("书").get(1);
		e.element("售价").setText("85元");
		
		OutputFormat format = OutputFormat.createPrettyPrint();
		format.setEncoding("UTF-8");
		XMLWriter writer = new XMLWriter(new FileOutputStream("src/book.xml"));
		writer.write(document);
		writer.close();	
	}
	
	//根据节点内容删除节点
	@Test
	public void test8() throws Exception{
		SAXReader reader = new SAXReader();
		Document document = reader.read(new File("src/book.xml"));
		
		Element root = document.getRootElement();
		list1(root);
		
		OutputFormat format = OutputFormat.createPrettyPrint();
		format.setEncoding("UTF-8");
		XMLWriter writer = new XMLWriter(new FileOutputStream("src/book.xml"));
		writer.write(document);
		writer.close();	
	}
	
	public void list1(Element e){
		String value = e.getText();
		if("Android".equals(value)){
			e.getParent().remove(e);
		}
		List<Element> list = e.elements();
		for(Element child : list){
			list1(child);
		}
	}
}