Вот код, который в настоящее время используется.
public String getStringFromDoc(org.w3c.dom.Document doc) {
try
{
DOMSource domSource = new DOMSource(doc);
StringWriter writer = new StringWriter();
StreamResult result = new StreamResult(writer);
TransformerFactory tf = TransformerFactory.newInstance();
Transformer transformer = tf.newTransformer();
transformer.transform(domSource, result);
writer.flush();
return writer.toString();
}
catch(TransformerException ex)
{
ex.printStackTrace();
return null;
}
}