How can I parse an XML String?

I am doing an application on Android, my error is as follows, from the Application, I send a parameter to a query, from a php, within this php, when it makes the query, it generates a response in a way structuring an XML. (I enclose the php so you can see how I have done it.)

    <?php
$link = mysqli_connect("mysql.hostinger.es", "u126083979_admin", "123456", "u126083979_lugar");
     if(isset($_POST['nombre']))
     {
      $nombre = $_POST['nombre'];
      $query1 = "SELECT * FROM Sitio WHERE Nombre = '".$nombre."'";
       if($result = mysqli_query($link, $query1))
       {
             echo "<Sitios>";
             while($Sitio = mysqli_fetch_array($result))
             {
              echo "<Sitio>";
              echo "<Nombre>" . $Sitio['Nombre'] . "</Nombre>";
              echo "<ImagenPrin>" . $Sitio['ImagenPrin'] . "</ImagenPrin>";
              echo "</Sitio>";
             }
             echo "</Sitios>";
             mysqli_free_result($result);

       }
       else
       {
         echo "ERROR: $sql. " . mysqli_error($link);
       }
     }
?>

Starting from my php giving me the answer in the form of xml, in the class I read, this answer in the following way.

int response_code = conexion.getResponseCode();

                if (response_code == HttpURLConnection.HTTP_OK) {
                    // Lee los datos enviados desde el php
                    InputStream input = conexion.getInputStream();
                    BufferedReader reader = new BufferedReader(new InputStreamReader(input));
                    StringBuilder result = new StringBuilder();
                    String line;
                    String vble="";
                    while ((line = reader.readLine()) != null) {
                        result.append(line);
                        vble=vble+line;                       
                    }

Now, as I understand it, the answer is stored in the Variable String vble , right now, and what I want right now is to parse the variable. I have it in the following way.

SAXParserFactory factory = SAXParserFactory.newInstance();
                    SAXParser saxParser = factory.newSAXParser();
                    SaxHandlerSitio handler = new SaxHandlerSitio();
                    saxParser.parse(vble, handler);

I do not understand why I am not parsea, finally I add my parse class through SAXHANDLER.

public class SaxHandlerSitio extends DefaultHandler{
    private List<Sitio> sitios;
    private Sitio sitioAc;
    private StringBuilder sbText;
    public Boolean parsingError = false;



    public List<Sitio> getSitios(){
        return sitios;
    }


    @Override
    public void startDocument() throws SAXException {

        super.startDocument();

        sitios = new ArrayList<Sitio>();
        sbText = new StringBuilder();
    }

    @Override
    public void startElement(String uri, String localName, String name, Attributes attributes) throws SAXException {

        super.startElement(uri, localName, name, attributes);

        if (localName.equals("Sitio")) {
            sitioAc = new Sitio(name, 0,0);
        }
    }

    @Override
    public void characters(char[] ch, int start, int length)
            throws SAXException {

        super.characters(ch, start, length);

        if (this.sitioAc != null)
            sbText.append(ch, start, length);
    }


    @Override
    public void endElement(String uri, String localName, String name)
            throws SAXException {

        super.endElement(uri, localName, name);
        double value;
        int valor = 0;
        if (this.sitioAc != null) {

            if (localName.equals("Nombre")) {
                sitioAc.setNombre(sbText.toString().trim());
            }
            else if (localName.equals("Latitud")) {
                value = Double.parseDouble(sbText.toString().trim());
                sitioAc.setLatitud(value);
            }
            else if (localName.equals("Longitud")) {
                value = Double.parseDouble(sbText.toString().trim());
                sitioAc.setLongitud(value);
            }
            else if (localName.equals("ImagenPrin")) {
                sitioAc.setImagen(sbText.toString().trim());
            }
            else if (localName.equals("Sitio")) {
                sitios.add(sitioAc);
            }
            sbText.setLength(0);
        }
    }

}

These are the mistakes that come to me

04-18 18:04:45.530 12331-20851/com.adilosa94.theturistllion W/System.err: java.io.IOException: Couldn't open <Sitios><Sitio><Nombre>Basílica de San Isidoro</Nombre><ImagenPrin>http://theturistllion.hol.es/upload/Imagenes/Sitios%20Principal/san_isidoro.jpg</ImagenPrin></Sitio></Sitios>
    04-18 18:04:45.533 12331-20851/com.adilosa94.theturistllion W/System.err: Caused by: java.net.MalformedURLException: Protocol not found: <Sitios><Sitio><Nombre>Basílica de San Isidoro</Nombre><ImagenPrin>http://theturistllion.hol.es/upload/Imagenes/Sitios%20Principal/san_isidoro.jpg</ImagenPrin></Sitio></Sitios>