something like this could work:

String requestQuery = "http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20weather.forecast%20where%20location%3D90210&format=xml"
HttpClient client = new HttpClient();
GetMethod method = new GetMethod(requestQuery);
// call method.getResultAsStream and store in an InputStream
// use inputStream result and save in a Document
// parse that via Xpath?

Mozilla released a JavaScript engine for Java called Rhino. Just look up the ScriptEngineManager class of Java SE at http://goo.gl/AoqKV and the ScriptEngine class at http://goo.gl/W79Mc. Or just lookup http://goo.gl/ExT3P.