java - Getting UnknownHostException instead of SocketTimeOutExcepetion -

i new android , java. , trying learn android app development udacity. trying run code , expecting sockettimeoutexcepetion getting unknownhostexception.

try {     final string base_url = "http://api.openweathermap.org/data/2.5/forecast/daily?";     final string zip = "zip";     final string mode = "mode";     final string units = "units";     final string count = "cnt";     final string app_id = "appid";      uri builturi = uri.parse(base_url).buildupon()                       .appendqueryparameter(zip, params[0] + ",in")                       .appendqueryparameter(mode,format)                       .appendqueryparameter(units, units)                       .appendqueryparameter(count, integer.tostring(numdays))                       .appendqueryparameter(app_id, buildconfig.open_weather_map_api_key)                       .build();     string str = java.net.urldecoder.decode(builturi.tostring());     url url = new url(str);      urlconnection = (httpurlconnection) url.openconnection();     urlconnection.setrequestmethod("get");     urlconnection.setconnecttimeout(5000);     urlconnection.setreadtimeout(5000);     urlconnection.connect();      inputstream inputstream = urlconnection.getinputstream();     stringbuffer buffer = new stringbuffer();      if (inputstream == null) {         return null;     }      reader = new bufferedreader(new inputstreamreader(inputstream));      string line;      while ((line = reader.readline()) != null)         buffer.append(line + "/n");      if (buffer.length() == 0)         return null;      forecastjsonstr = buffer.tostring();      log.v(log_tag,"json forcast string:" +forecastjsonstr); }catch(sockettimeoutexception e) {     startactivity(new intent(getactivity(),checknet.class)); } catch (ioexception e) {     log.e("fetchweathertask", "error:" + e.tostring());     return null; } 

i tested on phone running android version 4.0.4. , while testing had mobile data , wifi off

when mobile data , wifi turned off, socket layer unable resolve internet addresses (e.g. "openweathermap.org") ip address. why unknownhostexception.

whereas, when you're on network, , it's able resolve ip addresses, , server fails reply, sockettimeoutexception.