How to save parsed and changed DOM document in xml file?

I have xml-file. I need to read it, make some changes and write new changed version to some new destination.

I managed to read, parse and patch this file (with DocumentBuilderFactory, DocumentBuilder, Document and so on).

But I cannot find a way how to save that file. Is there a way to get it's plain text view (as String) or any better way?

Something like this works:

Transformer transformer = TransformerFactory.newInstance().newTransformer();
Result output = new StreamResult(new File("output.xml"));
Source input = new DOMSource(myDocument);

transformer.transform(input, output);

That will work, provided you're using xerces-j:

public void serialise(org.w3c.dom.Document document) {
  java.io.ByteArrayOutputStream data = new java.io.ByteArrayOutputStream();
  java.io.PrintStream ps = new java.io.PrintStream(data);

  org.apache.xml.serialize.OutputFormat of =
                      new org.apache.xml.serialize.OutputFormat("XML", "ISO-8859-1", true);
  of.setIndent(1);
  of.setIndenting(true);
  org.apache.xml.serialize.XMLSerializer serializer =
                      new org.apache.xml.serialize.XMLSerializer(ps, of);
  // As a DOM Serializer
  serializer.asDOMSerializer();
  serializer.serialize(document);

  return data.toString();
}