import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathFactory;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;


public class Main
{
    public static void main(String[] args) throws Exception
    {
        DocumentBuilderFactory domFactory = DocumentBuilderFactory.newInstance();
        domFactory.setNamespaceAware(true);
        DocumentBuilder builder = domFactory.newDocumentBuilder();
        Document doc = builder.parse("input.xml");

        XPath xpath = XPathFactory.newInstance().newXPath();

        XPathExpression expr = xpath.compile("/stress_test/protocollo/utenti");
        Object result = expr.evaluate(doc, XPathConstants.NODESET);

        NodeList nodes = (NodeList) result;
        System.out.println("Ho trovato " + nodes.getLength() + " nodi");

        for (int i = 0; i < nodes.getLength(); i++)
        {
            Element utente = (Element) nodes.item(i);

            String username = xpath.evaluate("utente/username", utente);
            String password = xpath.evaluate("utente/password", utente);

            System.out.println(username + " " + password);
        }
    }
}