这是一个添加一组数据的案例：

为第一个学生添加学校

src/stu.xml

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

<exam> 
  <student> 
    <name>张三</name>  
    <location>西安</location>  
    <grade>98</grade>  
  </student>  
  <student> 
    <name>李四</name>  
    <location>临潼</location>  
    <grade>59</grade> 
  </student> 
</exam>

package Dom4j;

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;

public class Add {
	public static void main(String[]args) throws DocumentException,IOException
	{
		  SAXReader reader = new SAXReader();
		  Document document = reader.read("src/stu.xml");
		  Element root = document.getRootElement();
		  Element student=root.element("student");
		  student.addElement("学校").addText("西瓜大");
		  
		  OutputFormat format = OutputFormat.createPrettyPrint();
		  format.setEncoding("UTF-8");
		  XMLWriter  writer = new XMLWriter( new FileOutputStream("src/stu.xml"),format );
	      writer.write( document );
	      writer.close();
	}
}