DOM in memory as XML

if (this == null) return null;
 
javax.xml.transform.TransformerFactory tf = javax.xml.transform.TransformerFactory.newInstance();
javax.xml.transform.Transformer transformer = tf.newTransformer();
transformer.setOutputProperty( javax.xml.transform.OutputKeys.METHOD, "xml");
transformer.setOutputProperty("encoding", "UTF-8");
transformer.setOutputProperty(javax.xml.transform.OutputKeys.INDENT,"yes");
transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "3" );
 
javax.xml.transform.dom.DOMSource source = new javax.xml.transform.dom.DOMSource(this);
if (source == null) return "Corrupted XML document: " + this.toString();
 
java.io.StringWriter os = new java.io.StringWriter();
javax.xml.transform.stream.StreamResult result = new javax.xml.transform.stream.StreamResult(os);
transformer.transform(source,result);
 
return os.toString ();