Unable to start receiver: android.os.NetworkOnMainThreadException with android JellyBean-Collection of common programming errors

I’m trying to develop a widget that updates itself every minute by a json resource, my problem is that when i try to launch it on jellybean it crashes, while with gingerbread works.

I saw here that i must move all internet connection to the main thread, right? At the moment i’ve a class called HttpRequest:

public class HttpRequest {    
    private String url;

    public HttpRequest(String url)
    {       
        this.url = url;
    }

    public String GetContent() throws ClientProtocolException, IOException
    {
        HttpClient client = new DefaultHttpClient();
        HttpGet request = new HttpGet(url);
        HttpResponse response = client.execute(request);

        String html = "";
        InputStream in = response.getEntity().getContent();
        BufferedReader reader = new BufferedReader(new InputStreamReader(in));
        StringBuilder str = new StringBuilder();
        String line = null;
        while((line = reader.readLine()) != null)
        {
            str.append(line);
        }
        in.close();
        html = str.toString();
        return html;
    }
}

Every minute is called updateAppWidget() that is a method of WidgetProvider class. Inside updateAppWidget() there is:

HttpRequest r = new HttpRequest("http://www.hwlogos.com/test.json");
remoteViews.setTextViewText(R.id.ip, r.GetContent());

Can you tell me how solve it steep by steep? thanks