Replace a Tree Node in a DOM tree in Java

import java.io.StringReader;
import java.io.StringWriter;
//w ww  .j  a  v a  2  s.  c o m
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Text;
import org.xml.sax.InputSource;

public class Main {
  static public void main(String[] arg) throws Exception {
    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
    dbf.setValidating(true);
    dbf.setNamespaceAware(true);
    dbf.setIgnoringElementContentWhitespace(true);

    DocumentBuilder builder = dbf.newDocumentBuilder();

    Document document = builder.parse(new InputSource("yourxmlFile.xml"));
    replacePerson(document,"newName","111111","newEmail@email.com");
    
    TransformerFactory tf = TransformerFactory.newInstance();
    Transformer trans = tf.newTransformer();
    StringWriter sw = new StringWriter();
    trans.transform(new DOMSource(document), new StreamResult(sw));
    System.out.println(sw.toString());


  }

  public static void replacePerson(Document doc, String name, String phone, String email) {
    Element newPersonNode = doc.createElement("person");

    Element nameNode = doc.createElement("name");
    newPersonNode.appendChild(nameNode);
    Text nametextNode = doc.createTextNode(name);
    nameNode.appendChild(nametextNode);

    Element phoneNode = doc.createElement("phone");
    newPersonNode.appendChild(phoneNode);
    Text phonetextNode = doc.createTextNode(phone);
    phoneNode.appendChild(phonetextNode);

    Element emailNode = doc.createElement("email");
    newPersonNode.appendChild(emailNode);
    Text emailtextNode = doc.createTextNode(email);
    emailNode.appendChild(emailtextNode);

    Element root = doc.getDocumentElement();
    Element oldPersonNode = (Element) root.getFirstChild();
    root.replaceChild(newPersonNode, oldPersonNode);
  }
}

<folks>
    <person>
        <name>B D</name>
        <phone>999 555-8888</phone>
        <email>b@xyz.net</email>
    </person>
</folks>
       
<result><![CDATA[    
  <?xml version="1.0" standalone="yes"?>
<folks>
    <person>
        <name>
            newName
        </name>
        <phone>
            111111
        </phone>
        <email>
            newEmail@email.com
        </email>
    </person>
</folks>