HttpRequest req = new HttpRequest();
        String url='abaccc';

        req.setEndpoint(url);
        req.setMethod('GET');
        // Send the request, and return a response
        HttpResponse res = h.send(req);
        XmlStreamReader reader = res.getXmlStreamReader();
        // Read through the XML
        while(reader.hasNext()) {
            System.debug('Event Type:' + reader.getEventType());
            if (reader.getEventType() == XmlTag.START_ELEMENT) {
            System.debug('Local name :'+reader.getLocalName());
            }
            reader.next();// Getting exception at this line.
        }