package com.example.xml.dom4j;import java.io.FileOutputStream;
import java.io.FileWriter;import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.XMLWriter;/*** dom4j框架学习 使用dom4j框架创建xml文档并输出保存* */
public class Dom4JTest1
{public static void main(String[] args) throws Exception{// 第一种方式：创建文档，并创建根元素// 创建文档:使用了一个Helper类Document document = DocumentHelper.createDocument();// 创建根节点并添加进文档Element root = DocumentHelper.createElement("student");document.setRootElement(root);// 第二种方式:创建文档并设置文档的根元素节点Element root2 = DocumentHelper.createElement("student");Document document2 = DocumentHelper.createDocument(root2);// 添加属性root2.addAttribute("name", "zhangsan");// 添加子节点:add之后就返回这个元素Element helloElement = root2.addElement("hello");Element worldElement = root2.addElement("world");helloElement.setText("hello Text");worldElement.setText("world text");// 输出// 输出到控制台XMLWriter xmlWriter = new XMLWriter();xmlWriter.write(document);// 输出到文件// 格式OutputFormat format = new OutputFormat("    ", true);// 设置缩进为4个空格，并且另起一行为trueXMLWriter xmlWriter2 = new XMLWriter(new FileOutputStream("student.xml"), format);xmlWriter2.write(document2);// 另一种输出方式，记得要调用flush()方法,否则输出的文件中显示空白XMLWriter xmlWriter3 = new XMLWriter(new FileWriter("student2.xml"),format);xmlWriter3.write(document2);xmlWriter3.flush();// close()方法也可以}
}

<?xml version="1.0" encoding="UTF-8"?>
<student/>

<?xml version="1.0" encoding="UTF-8"?><student name="zhangsan"><hello>hello Text</hello><world>world text</world>
</student>

<?xml version="1.0" encoding="UTF-8"?><students name="zhangsan"><hello name="lisi">hello Text1</hello><hello name="lisi2">hello Text2</hello><hello name="lisi3">hello Text3</hello><world name="wangwu">world text1</world><world name="wangwu2">world text2</world><world >world text3</world>
</students>

package com.example.xml.dom4j;import java.io.File;
import java.util.Iterator;
import java.util.List;import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.io.DOMReader;
import org.dom4j.io.SAXReader;/*** dom4j框架学习： 读取并解析xml* * */
public class Dom4JTest2
{public static void main(String[] args) throws Exception{SAXReader saxReader = new SAXReader();Document document = saxReader.read(new File("students.xml"));// 获取根元素Element root = document.getRootElement();System.out.println("Root: " + root.getName());// 获取所有子元素List<Element> childList = root.elements();System.out.println("total child count: " + childList.size());// 获取特定名称的子元素List<Element> childList2 = root.elements("hello");System.out.println("hello child: " + childList2.size());// 获取名字为指定名称的第一个子元素Element firstWorldElement = root.element("world");// 输出其属性System.out.println("first World Attr: "+ firstWorldElement.attribute(0).getName() + "="+ firstWorldElement.attributeValue("name"));System.out.println("迭代输出-----------------------");// 迭代输出for (Iterator iter = root.elementIterator(); iter.hasNext();){Element e = (Element) iter.next();System.out.println(e.attributeValue("name"));}System.out.println("用DOMReader-----------------------");DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();DocumentBuilder db = dbf.newDocumentBuilder();// 注意要用完整类名org.w3c.dom.Document document2 = db.parse(new File("students.xml "));DOMReader domReader = new DOMReader();// 将JAXP的Document转换为dom4j的DocumentDocument document3 = domReader.read(document2);Element rootElement = document3.getRootElement();System.out.println("Root: " + rootElement.getName());}}

Root: students
total child count: 6
hello child: 3
first World Attr: name=wangwu
迭代输出-----------------------
lisi
lisi2
lisi3
wangwu
wangwu2
null
用DOMReader-----------------------
Root: students