使用Web服务XML - NullPointerException

Question

我尝试使用xml，但我在线上获得了NullPointerException：

  InputStream is = res.getEntity().getContent();

我的消费方法可以检查网址中的xml

public class XMLDownloader {
    DefaultHttpClient client = new DefaultHttpClient();
    HttpGet method = new HttpGet("http://proapaplicativos.com.br/jccuritiba/listarEventos.php");
    HttpResponse res = null;
    NodeList result = null;
   // Thread t = new Thread();

    public NodeList GetNodeList() throws InterruptedException{   
        //String url = "http://fiscalartesp.cloudapp.net/Service1.svc/login?";

        new Thread(new Runnable() {
            public void run() {

                try {
                    res = client.execute(method);
                } catch (ClientProtocolException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                try{
                    URL urls;
                    urls = new URL("http://proapaplicativos.com.br/jccuritiba/listarEventos.php");
                    InputStream is = res.getEntity().getContent();
                    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
                    DocumentBuilder db = dbf.newDocumentBuilder();
                    Document doc = db.parse(new InputSource(urls.openStream()));
                    doc.getDocumentElement().normalize();
                    result = doc.getElementsByTagName("Evento");                         
                    is.close();
                }catch(Exception e){
                     Log.i("log_tag", "Error converting result "+e.toString());
                }     

            }
        }).start();
        /*
        new Thread(new Runnable() {
            public void run() {

        }).start();
        */
        while(result == null)
        {
            //Log.i("Aguardando", "Aguardando resposta");
        }


        return result;              
    }
}