Here's a utility class with some static methods I use for this:

package com.hostedtelecom.callcentreweb.util;

import java.io.*;
import java.util.*;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;
import org.w3c.dom.*;
import javax.xml.transform.*;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.dom.DOMSource;
import org.xml.sax.InputSource;

/**
* Utilty class for XML basic tasks
*/
public class XMLHelper
{
 /** Convert W3C XML Document to String.
 @param   document
 @return  String
 @throws  XMLHelperException
 */
 public static final String getDocumentAsString(Document document)
throws XMLHelperException
 {
   try
   {
     // Create source and result objects
     Source source = new DOMSource(document);
     StringWriter out = new StringWriter();
     Result result = new StreamResult(out);
     TransformerFactory tFactory = TransformerFactory.newInstance();
     Transformer transformer = tFactory.newTransformer();
     transformer.transform(source, result);
     return out.toString();
   }
   catch(Exception e)
   {
     throw new XMLHelperException("XML Document to String Error", e);
   }
 }

 /** Convert String to a W3C XML Document.
 @param   xmlString
 @return  Document
 @throws  XMLHelperException
 */
 public static final Document getDocument(String xmlString) throws
XMLHelperException
 {
   try
   {
     String nstr = null;
     //cannot have whitespace in the beginning of an xml document
     if (xmlString.charAt(0) != ' ')
     {
       nstr = removeInitialWS(xmlString);
     }
     else
     {
       nstr = xmlString;
     }

     DocumentBuilderFactory factory =
DocumentBuilderFactory.newInstance();
     factory.setNamespaceAware(true);
     factory.setIgnoringElementContentWhitespace(false);
     DocumentBuilder builder = factory.newDocumentBuilder();

     InputSource isXml = new InputSource (new StringReader(nstr));
     return builder.parse(isXml);
   }
   catch(Exception e)
   {
     throw new XMLHelperException("String to XML Document Error for
String:\n\n "+xmlString+" ", e);
   }
 }

 /**
   Remove any blank spaces in beginning of the XML declaration
 */
 public static final String removeInitialWS(String xmlString) throws
XMLHelperException
 {
   try
   {
     int pos = xmlString.indexOf("<");
     if (-1 == pos)
     {
       throw new Exception("Invalid XML, char '<' not found");
     }

     return xmlString.substring(pos);
   }
   catch(Exception e)
   {
     throw new XMLHelperException("String to XML Document Error for
String: \n\n "+xmlString+" ", e);
   }
 }

public static final String getNodeToString(Node node) throws
XMLHelperException
 {
   try
   {
     TransformerFactory tFactory = TransformerFactory.newInstance();
     Transformer transformer = tFactory.newTransformer();
     transformer.setOutputProperty("omit-xml-declaration", "yes");

     StringWriter sw = new StringWriter();
     StreamResult result = new StreamResult(sw);
     DOMSource source = new DOMSource( node );
     transformer.transform( source, result );

     return sw.getBuffer().toString();
    }
    catch(Exception e)
    {
      throw new XMLHelperException("XML Document to String Err", e);
    }
 }
}

HTH,
iksrazal
http://www.braziloutsource.com