How can i write the DOM tree to the XML File?

Question

Asslamo ala mn etb3a Alhoda.
My problem priefly is that i can't write the DOM tree to XML file.
I write following code to give the user the ability to input the name of data base which he want to create.
If i wrote DB name,its atrributes and its values succefully to XML file ,then i'll read it succefully to RAM.
It'll be simple DBMS.
***My code***
import javax.swing.*;
import javax.xml.parsers.*;
import org.w3c.dom.Document;
import org.w3c.dom.DOMException;
import org.w3c.dom.Element;
public class Main {
     * @param args
public static void main(String[] args) {
     // TODO Auto-generated method stub     
     String DBname;
DBname=JOptionPane.showInputDialog("Enter Your Data Base Name");
OPerations O=new OPerations();
     O.creatDB(DBname);
class OPerations {
public void creatDB(String name){
     //get an empty Document
     DocumentBuilderFactory f; f=DocumentBuilderFactory.newInstance();
     try {
          builder = f.newDocumentBuilder();
          Document doc= builder.newDocument();
     //Build tree DOM With the root Node
          Element root=doc.createElement(name);
     //add the root element to thevdocument
          doc.appendChild(root);
catch (ParserConfigurationException e) {
     // TODO Auto-generated catch block
          e.printStackTrace();
}

Answer 1

Do an identity transformation to output it:TransformerFactory tf = TransformerFactory.newInstance();
Transformer tr = tf.newTransformer();
tr.transform(new DOMSource(doc), new StreamResult(new FileOutputStream(new File(filename))));(typed without syntax check)