如何给xml文件添加新的element

下面是一个例子, 如何添加新的</property>
<properties>

</property>
...
...
<property>
  <name>Workaround</name>
<option>java.property.com.entrust.toolkit.x509.CertVerifier.ForceV1CertAsCA</option>
  <default>true</default>
  <description>thanks</description>
</property>

</properties>

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.*;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;

/**
 * Created by IntelliJ IDEA.
 * User: Michael
 * Date: 12/3/11
 * Time: 3:16 PM
 * To change this template use File | Settings | File Templates.
 */
public class XMLApender {

    public static void main(String[] args) {

        DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder docBuilder = null;
        OutputStreamWriter outputStreamWriter = null;
        try {
            docBuilder = docFactory.newDocumentBuilder();
            Document doc = docBuilder.parse("C:\\Documents and Settings\\Michael\\My Documents\\bwengine.xml");

            Element properties = doc.getDocumentElement();
            NodeList nodeList = doc.getElementsByTagName("option");
            for(int i=0; i< nodeList.getLength(); i++){
                    Node  node = nodeList.item(i);
                    String text = node.getTextContent();
                   if("java.property.com.entrust.toolkit.x509.CertVerifier.ForceV1CertAsCA".equals(text)){
                                     return;
                    }
            }

            FileOutputStream outputStream = new FileOutputStream("C:\\Documents and Settings\\Michael\\My Documents\\bwengine.xml");
            outputStreamWriter = new OutputStreamWriter(outputStream);

            Node property = doc.createElement("property");

            Node name = doc.createElement("name");
            name.setTextContent("Workaround");
            Node option = doc.createElement("option");
            option.setTextContent("java.property.com.entrust.toolkit.x509.CertVerifier.ForceV1CertAsCA");
            Node defau1t = doc.createElement("default");
            defau1t.setTextContent("true");
            Node description = doc.createElement("description");
            description.setTextContent("thanks");

            property.appendChild(name);
            property.appendChild(option);
            property.appendChild(defau1t);
            property.appendChild(description);

            properties.appendChild(property);

            Transformer transformer = TransformerFactory.newInstance().newTransformer();
            transformer.setOutputProperty(OutputKeys.INDENT, "yes");
            StreamResult result = new StreamResult(outputStreamWriter);
            DOMSource source = new DOMSource(doc);
            transformer.transform(source, result);

            outputStreamWriter.flush();
            outputStreamWriter.close();

            String xmlString = result.getWriter().toString();
            System.out.println(xmlString);


        } catch (ParserConfigurationException e) {
            e.printStackTrace();
        } catch (SAXException e) {
            e.printStackTrace();
        } catch (TransformerConfigurationException e) {
            e.printStackTrace();
        } catch (TransformerException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }
}