dom4j解析xml常用操作

Book.xml

<?xml version="1.0" encoding="UTF-8"?>
<书架> 
  <书> 
    <书名>数据结构</书名>  
    <作者>严蔚敏</作者>  
    <售价>29.00元</售价>  
  </书>  
  <书> 
    <书名>高等数学</书名>  
    <作者>同济大学数学系</作者>  
    <售价>55.00元</售价> 
  </书> 
</书架>

Parsing XML

File file=new File("Book.xml");
SAXReader saxReader=new SAXReader();
Document document = saxReader.read(file);

//或者,因为后面如果进行写入的话还会需要File流，所有就选择第一种方式

SAXReader saxReader=new SAXReader();
Document document = saxReader.read("Book.xml");

写入XML文件

//直接写入
XMLWriter writer = new XMLWriter(new FileWriter(file) );
writer.write( document );
writer.close();

//格式化后写入，开发时方便阅读
OutputFormat format = OutputFormat.createPrettyPrint();
writer = new XMLWriter( new FileOutputStream(file), format );
writer.write( document );

//紧凑格式写入，生产环境下使用
format = OutputFormat.createCompactFormat();
writer = new XMLWriter( new FileOutputStream(file), format );
writer.write( document );

操作元素节点和属性节点

package dom4j;

import java.io.File;

import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.util.List;

import org.dom4j.Attribute;
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.Before;
import org.junit.Test;

public class Dom4jTest {
	
	private File file;
	private Document document;
	
	@Before
	public void before(){
		try {
			file=new File("D:\\Users\\14758\\Workspaces\\MyEclipse 2017 CI\\test\\src\\dom4j\\Book.xml");
			SAXReader saxReader=new SAXReader();
			document = saxReader.read(file);
		} catch (DocumentException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
	/**
	 * 1.查询第一本书的书名，并输出到控制台
	 */
	
	@Test
	public void test1(){
		
		Element rootElement = document.getRootElement();
		List<Element> elements = rootElement.elements();
		Element element = elements.get(0);
		String book = element.elementText("书名");
		System.out.println(book);
		
	}
	
	/**
	 * 2.查询第二本书的售价，并输出到控制台
	 */
	@Test
	public void test2(){
		
		Element rootElement = document.getRootElement();
		List<Element> elements = rootElement.elements();
		Element element = elements.get(1);
		String price = element.elementText("售价");
		System.out.println(price);
		
	}
	/**
	 * 3.给第一本书添加一个特价节点（2种方式）
	 * @throws IOException 
	 */
	@Test
	public void test3() throws IOException{
		
		Element createElement = DocumentHelper.createElement("特价");
		createElement.setText("30.00元");
		Element rootElement = document.getRootElement();
		List<Element> elements = rootElement.elements();
		Element book = elements.get(0);
		book.add(createElement);
		write();
		
	}
	/**
	 * 4.给第二本书在作者节点前插入一个特价节点
	 * @throws IOException 
	 */
	@Test
	public void test4() throws IOException{
		Element rootElement = document.getRootElement();
		List<Element> elements = rootElement.elements();
		Element createElement = DocumentHelper.createElement("特价");
		createElement.setText("30.00元");
		List book = elements.get(1).elements();
		book.add(1, createElement);
		Writer osWrite=new OutputStreamWriter(new FileOutputStream(file));//创建输出流
        OutputFormat format = OutputFormat.createPrettyPrint();  //获取输出的指定格式
        format.setEncoding("UTF-8");//设置编码 ，确保解析的xml为UTF-8格式
        XMLWriter writer = new XMLWriter(osWrite,format);//XMLWriter 指定输出文件以及格式
        writer.write(document);//把document写入xmlFile指定的文件(可以为被解析的文件或者新创建的文件)
        writer.flush();
        writer.close();
	}
	/**
	 * 5.删除第二本书的特价节点（2种方式）
	 * @throws IOException 
	 */
	@Test
	public void test5() throws IOException{
		Element rootElement = document.getRootElement();
		List<Element> elements = rootElement.elements();
		Element book = elements.get(1);
		Element bargin = book.element("特价");
		book.remove(bargin);
		write();
	}
	
	/**
	 * 6.更新第一本书的特价节点的内容为19.8元
	 * @throws IOException
	 */
	@Test
	public void test6() throws IOException{
		Element rootElement = document.getRootElement();
		List<Element> elements = rootElement.elements();
		Element book = elements.get(0);
		Element bargin = book.element("特价");
		bargin.setText("19.8元");
		write();
	}
	/**
	 * 1.给第一本书添加一个属性，如：出版社="清华大学出版社"(2种方式)
	 * @throws IOException 
	 */
	@Test
	public void test7() throws IOException{
		Element rootElement = document.getRootElement();
		List<Element> elements = rootElement.elements();
		Element book = elements.get(0);
		book.addAttribute("出版社", "清华大学出版社");
		//book.setAttributeValue("出版社", "出版社");
		write();
	}
	/**
	 * 2.在控制台上打印输出第一本书的出版社属性的值,并更新属性的值为“人民出版社”(3种方式)
	 * method1
	 * @throws IOException 
	 */
	@Test
	public void test8() throws IOException{
		Element rootElement = document.getRootElement();
		Element book = rootElement.element("书");
		String attributeValue = book.attributeValue("出版社");
		Attribute attribute = book.attribute("出版社");
		attribute.setValue("人民出版社");
		System.out.println(attributeValue);
		write();
	}
	/**
	 * 2.在控制台上打印输出第一本书的出版社属性的值,并更新属性的值为“人民出版社”(3种方式)
	 * method2
	 * @throws IOException 
	 */
	@Test
	public void test9() throws IOException{
		Element rootElement = document.getRootElement();
		Element book = rootElement.element("书");
		book.setAttributeValue("出版社", "清华大学出版社");
		write();
	}
	
	/**
	 * 2.在控制台上打印输出第一本书的出版社属性的值,并更新属性的值为“人民出版社”(3种方式)
	 * method3
	 * @throws IOException 
	 */
	@Test
	public void test10() throws IOException{
		Element rootElement = document.getRootElement();
		Element book = rootElement.element("书");
		write();
	}
	/**
	 * 3.删除第一本书的出版社属性(2种方式)
	 * @throws IOException 
	 */
	@Test
	public void test11() throws IOException{
		Element rootElement = document.getRootElement();
		Element book = rootElement.element("书");
		Attribute attribute = book.attribute("出版社");
		book.remove(attribute);
		write();
	}
	
	/**
	 * 3.删除第一本书的出版社属性(2种方式)
	 * @throws IOException 
	 */
	@Test
	public void test12() throws IOException{
		Element rootElement = document.getRootElement();
		List<Element> elements = rootElement.elements();
		Element book = elements.get(0);
		Attribute attribute = book.attribute("出版社");
		book.remove(attribute);
		write();
	}
	/**
	 * （作业）给第二本书添加一个属性，如：编号="b01"
	 * @throws IOException 
	 */
	@Test
	public void test13() throws IOException{
		Element rootElement = document.getRootElement();
		List<Element> elements = rootElement.elements();
		Element book = elements.get(1);
		book.addAttribute("编号", "b001");
		write();
	}
	/**
	 * （作业）给第二本书添加一个属性，如：编号="b01"
	 * @throws IOException 
	 */
	@Test
	public void test14() throws IOException{
		Element rootElement = document.getRootElement();
		List<Element> elements = rootElement.elements();
		Element book = elements.get(1);
		Attribute createAttribute = DocumentHelper.createAttribute(book, "编号", "b001");
		book.add(createAttribute);
		write();
	}
	/**
	 * 5.（作业）在控制台上打印输出第二本书编号属性的值,并更新该属性的值
	 */
	@Test
	public void test15(){
		Element rootElement = document.getRootElement();
		List<Element> elements = rootElement.elements();
		Element book = elements.get(1);
		System.out.println(book.attributeValue("编号"));
		
	}
	/**
	 * 6.（作业）删除第二本书的编号属性
	 * @throws IOException 
	 */
	@Test
	public void test16() throws IOException{
		
		Element rootElement = document.getRootElement();
		List<Element> elements = rootElement.elements();
		Element book = elements.get(1);
		Attribute attribute = book.attribute("编号");
		book.remove(attribute);
		write();
	}
	
	public void write() throws IOException{
		Writer osWrite=new OutputStreamWriter(new FileOutputStream(file));//创建输出流
        OutputFormat format = OutputFormat.createPrettyPrint();  //获取输出的指定格式
        format.setEncoding("UTF-8");//设置编码 ，确保解析的xml为UTF-8格式
        XMLWriter writer = new XMLWriter(osWrite,format);//XMLWriter 指定输出文件以及格式
        writer.write(document);//把document写入xmlFile指定的文件(可以为被解析的文件或者新创建的文件)
        writer.flush();
        writer.close();
	}
}