DOM4J 代码演示

package com.openbox.DOM4JDemo;

import java.io.File;
import java.io.FileOutputStream;
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;

//使用JUnit5做单元测试，按序依次执行下面的方法
public class DOM4JTest {

	@Test
	public void testCreate() throws Exception {
		//1.用doucumentHelper类创建一个document对象
		Document doc = DocumentHelper.createDocument();

		//2.先创建他们的根节点
		Element rootEle = doc.addElement("contact");

		//3.再创建linkman元素
		Element linkmanEle = rootEle.addElement("linkman");

		//4.创建linkman元素下，其它所有元素
		Element nameEle = linkmanEle.addElement("name");
		nameEle.setText("陆小凤");
		linkmanEle.addElement("address").setText("中国*");
		linkmanEle.addAttribute("id", "8877");

		//5.同步操作
		//格式化
		OutputFormat fOutputFormat = OutputFormat.createPrettyPrint();
		FileOutputStream out = new FileOutputStream("res/contact.xml");
		//创建XMLWriter 对象
		XMLWriter writer = new XMLWriter(out,fOutputFormat);
		//将DOM内存对象，写到磁盘文件中
		writer.write(doc);
		
	}
	
	@Test
	public void testQuery() throws Exception {

		File file = new File("res/contact.xml");
		//1.NEW一个 SAXRader 对象
		SAXReader reader = new SAXReader();
		//2.将XML文件读入，生成document对象
		Document document = reader.read(file);
		//3.取得根元素
		Element rootEle = document.getRootElement();
		//4.得到linkman元素
		List<Element> linkmanList = rootEle.elements("linkman");
		//5.遍历所有linkman子元素
		for (Element element : linkmanList) {
			String id = element.attributeValue("id");
			String name = element.elementText("name");
			String address = element.elementText("address");
		    System.out.println("id="+id+",name="+name+",address="+address);
		}
	}
	
	@Test
	public void testAdd() throws Exception {
		File file = new File("res/contact.xml");

		//1.NEW一个 SAXRader 对象
		SAXReader reader = new SAXReader();
		//2.将XML文件读入，生成document对象
		Document document = reader.read(file);
		//3.取得根元素
		Element rootEle = document.getRootElement();	
		//4.增加linkman
		Element linkmanEle=rootEle.addElement("linkman").addAttribute("id", "9876");
		//5.增加linkman元素下的子元素
		linkmanEle.addElement("name").setText("王宝强");
		linkmanEle.addElement("address").setText("中国内地");
		//6.同步保存
		OutputFormat format=OutputFormat.createPrettyPrint();
		FileOutputStream out=new FileOutputStream(file);
		
		XMLWriter writer= new XMLWriter(out, format);
		writer.write(document);
		writer.close();
		
	}

	
	@Test
	public void testDelete() throws Exception {
		File file = new File("res/contact.xml");
		//1.NEW一个 SAXRader 对象
		SAXReader reader = new SAXReader();
		//2.将XML文件读入，生成document对象
		Document document = reader.read(file);
		//3.取得根元素
		Element rootEle = document.getRootElement();
		//4.得到所有linkman元素
		List<Element> linkmanList = rootEle.elements("linkman");
		//5.删除名字为王宝强的联系人
		for (Element element : linkmanList) {
			if(element.elementText("name").equals("王宝强")) {				
				rootEle.remove(element);
				//System.out.println("delete "+element.elementText("name"));
			}
		}
		
		//6.同步保存
		OutputFormat format=OutputFormat.createPrettyPrint();
		FileOutputStream out=new FileOutputStream(file);
		
		XMLWriter writer= new XMLWriter(out, format);
		writer.write(document);
		writer.close();
	}
}