android - Weather is not showing when run on real device -

i use http://api.openweathermap.org/data/2.5/weather show weather working in emulator when send location in using location setting not working on real device. not show error message in log.
can 1 tell me doing wrong?

i add permissions in androidmanifest.xml also.

mainactivity.java

public class mainactivity extends appcompatactivity implements locationlistener {      textview txtcity, txtlastupdate, txtdescription, txthumidity, txttime, txtcelsius;     imageview imageview;      locationmanager locationmanager;     string provider;     static double lat, lng;     openweathermap openweathermap = new openweathermap();      int my_permission = 0;      @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_main);          //control         txtcity = (textview) findviewbyid(r.id.txtcity);         txtlastupdate = (textview) findviewbyid(r.id.txtlastupdate);         txtdescription = (textview) findviewbyid(r.id.txtdescription);         txthumidity = (textview) findviewbyid(r.id.txthumidity);         txttime = (textview) findviewbyid(r.id.txttime);         txtcelsius = (textview) findviewbyid(r.id.txtcelsius);         imageview = (imageview) findviewbyid(r.id.imageview);           //get coordinates         locationmanager = (locationmanager) getsystemservice(context.location_service);         provider = locationmanager.getbestprovider(new criteria(), false);          if (activitycompat.checkselfpermission(this, manifest.permission.access_fine_location) != packagemanager.permission_granted && activitycompat.checkselfpermission(this, manifest.permission.access_coarse_location) != packagemanager.permission_granted) {               activitycompat.requestpermissions(mainactivity.this, new string[]{                     manifest.permission.internet,                     manifest.permission.access_coarse_location,                     manifest.permission.access_fine_location,                     manifest.permission.access_network_state,                     manifest.permission.system_alert_window,                     manifest.permission.write_external_storage               }, my_permission);         }         location location = locationmanager.getlastknownlocation(provider);         if (location == null)             log.e("tag","no location");     }      @override     protected void onpause() {         super.onpause();         if (activitycompat.checkselfpermission(this, manifest.permission.access_fine_location) != packagemanager.permission_granted && activitycompat.checkselfpermission(this, manifest.permission.access_coarse_location) != packagemanager.permission_granted) {             activitycompat.requestpermissions(mainactivity.this, new string[]{                     manifest.permission.internet,                     manifest.permission.access_coarse_location,                     manifest.permission.access_fine_location,                     manifest.permission.access_network_state,                     manifest.permission.system_alert_window,                     manifest.permission.write_external_storage               }, my_permission);         }         locationmanager.removeupdates(this);     }      @override     protected void onresume() {         super.onresume();         if (activitycompat.checkselfpermission(this, manifest.permission.access_fine_location) != packagemanager.permission_granted && activitycompat.checkselfpermission(this, manifest.permission.access_coarse_location) != packagemanager.permission_granted) {             activitycompat.requestpermissions(mainactivity.this, new string[]{                     manifest.permission.internet,                     manifest.permission.access_coarse_location,                     manifest.permission.access_fine_location,                     manifest.permission.access_network_state,                     manifest.permission.system_alert_window,                     manifest.permission.write_external_storage               }, my_permission);         }         locationmanager.requestlocationupdates(provider, 400, 1, this);     }      @override     public void onlocationchanged(location location) {         lat = location.getlatitude();         lng = location.getlongitude();          new getweather().execute(common.apirequest(string.valueof(lat),string.valueof(lng)));     }      @override     public void onstatuschanged(string provider, int status, bundle extras) {      }      @override     public void onproviderenabled(string provider) {      }      @override     public void onproviderdisabled(string provider) {      }      private class getweather extends asynctask<string,void,string>{         progressdialog pd = new progressdialog(mainactivity.this);           @override         protected void onpreexecute() {             super.onpreexecute();             pd.settitle("please wait...");             pd.show();          }           @override         protected string doinbackground(string... params) {             string stream = null;             string urlstring = params[0];              helper http = new helper();             stream = http.gethttpdata(urlstring);             return stream;         }          @override         protected void onpostexecute(string s) {             super.onpostexecute(s);             if(s.contains("error: not found city")){                 pd.dismiss();                 return;             }             gson gson = new gson();             type mtype = new typetoken<openweathermap>(){}.gettype();             openweathermap = gson.fromjson(s,mtype);             pd.dismiss();              txtcity.settext(string.format("%s,%s",openweathermap.getname(),openweathermap.getsys().getcountry()));             txtlastupdate.settext(string.format("last updated: %s", common.getdatenow()));             txtdescription.settext(string.format("%s",openweathermap.getweather().get(0).getdescription()));             txthumidity.settext(string.format("%d%%",openweathermap.getmain().gethumidity()));             txttime.settext(string.format("%s/%s",common.unixtimestamptodatetime(openweathermap.getsys().getsunrise()),common.unixtimestamptodatetime(openweathermap.getsys().getsunset())));             txtcelsius.settext(string.format("%.2f °c",openweathermap.getmain().gettemp()));             picasso.with(mainactivity.this)                     .load(common.getimage(openweathermap.getweather().get(0).geticon()))                     .into(imageview);          }      } } 

common.java

public class common { public static string api_key = "mykey"; public static string api_link = "http://api.openweathermap.org/data/2.5/weather";  @nonnull public static string apirequest(string lat, string lng){     stringbuilder sb = new stringbuilder(api_link);     sb.append(string.format("?lat=%s&lon=%s&appid=%s&units=metric",lat,lng,api_key));     return sb.tostring(); }  public static string unixtimestamptodatetime(double unixtimestamp){     dateformat dateformat = new simpledateformat("hh:mm");     date date = new date();     date.settime((long)unixtimestamp*1000);     return dateformat.format(date); }  public static string getimage(string icon){     return string.format("http://openweathermap.org/img/w/%s.png",icon); }  public static string getdatenow(){     dateformat dateformat = new simpledateformat("dd mmmm yyyy hh:mm");     date date = new date();     return dateformat.format(date); } 

}

the method getlastknownlocation location info when last time, it's may null.

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