原文地址：
https://www.tutorialspoint.com/java_xml/java_dom4j_create_document.htm

这是想创建的XML：

<?xml version = "1.0" encoding = "UTF-8"?>
<cars>
   <supercars company = "Ferrari">
      <carname type = "formula one">Ferrari 101</carname>
      <carname type = "sports">Ferrari 202</carname>
   </supercars>
</cars>

Java：

package com.tutorialspoint.xml;

import java.io.IOException;
import java.io.UnsupportedEncodingException;

import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.XMLWriter;

public class DOM4JCreateXMLDemo {

   public static void main(String[] args) {
      
      try {
         Document document = DocumentHelper.createDocument();
         Element root = document.addElement( "cars" );
         Element supercarElement = root.addElement("supercars")
            .addAttribute("company", "Ferrai");

         supercarElement.addElement("carname")
            .addAttribute("type", "Ferrari 101")
            .addText("Ferrari 101");

         supercarElement.addElement("carname")
            .addAttribute("type", "sports")
            .addText("Ferrari 202");

         // Pretty print the document to System.out or System.out.println(document.asXML())
         OutputFormat format = OutputFormat.createPrettyPrint();
         XMLWriter writer;
         writer = new XMLWriter( System.out, format );
         writer.write( document );
      } catch (UnsupportedEncodingException e) {
         e.printStackTrace();
      } catch (IOException e) {
         e.printStackTrace();
      }
   }
}