// the URL returns an XML doc
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
Document doc = db.parse(url.openStream());
XPathFactory xPathfactory = XPathFactory.newInstance();
XPath xpath = xPathfactory.newXPath();
XPathExpression exprmin =
xpath.compile("/dwml/data/parameters/temperature[@type='minimum']/value[1]");
String minimum = (String) exprmin.evaluate(doc, XPathConstants.STRING);
// update datastore