How do i show the marker at given position on google map in android? -

i developing app using google map.in want show marker @ location longitude latitude values fetch form server.how show marker @ fetched longitude , latitude value? following code fetch longitude , latitude values server successfully, want show marker on google map fetch langitude , latitude.how do?

//java code public class location_track1 extends activity {      private static final string tag = "location_track1";     private static final long interval = 1000 * 60 * 1; //1 minute     private static final long fastest_interval = 1000 * 60 * 1; // 1 minute      private static final float smallest_displacement = 0.25f; //quarter of meter     button btnfusedlocation;     textview tvlocation;     locationrequest mlocationrequest;     googleapiclient mgoogleapiclient;     location mcurrentlocation;     string mlastupdatetime;     googlemap googlemap;     private imageview mcurrentpointer;      private double longitude;     private double latitude; //    private arraylist<latlng> points; //added     private list<latlng> points = new arraylist<>();     polyline line; //added      textview tv_mobno, tv_latitude, tv_longitude, tv_time;     string getlatitude;     string getlongitude;     button slocation;      jsonarray result = null;      progressdialog mprogressdialog;     arraylist<hashmap<string, string>> arraylist;     static string con = "con";     jsonobject jsonobject;     jsonarray jsonarray;      private string url ="";      private static final string tag_user = "result";      //   private static final string tag_sname = "pseats";     private static final string tag_long = "longitude";     private static final string tag_lat = "latitude";     private static final string tag_address = "paddress";      protected void createlocationrequest() {         mlocationrequest = new locationrequest();         mlocationrequest.setinterval(interval);         mlocationrequest.setfastestinterval(fastest_interval);         mlocationrequest.setsmallestdisplacement(smallest_displacement); //added         mlocationrequest.setpriority(locationrequest.priority_high_accuracy);     }      @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.location_track);          log.d(tag, "oncreate ...............................");          tv_mobno=(textview)findviewbyid(r.id.textview_mob);         tv_latitude=(textview)findviewbyid(r.id.textview_latitude);         tv_longitude=(textview)findviewbyid(r.id.textview_longitude);         tv_time=(textview)findviewbyid(r.id.textview_time);         slocation=(button)findviewbyid(r.id.button_slocation);          url = "http://example.in/gmap_track.php";       //   points = new arraylist<latlng>();           googlemap = ((mapfragment) getfragmentmanager().findfragmentbyid(r.id.map))                 .getmap();           slocation.setonclicklistener(new view.onclicklistener() {             @override             public void onclick(view v) {                 // new downloadjson().execute();                 new jsonparse().execute();             }         });      }      private class jsonparse extends asynctask<string, string, jsonobject> {         private progressdialog pdialog;         @override         protected void onpreexecute() {             super.onpreexecute();              pdialog = new progressdialog(location_track1.this);             pdialog.setmessage("getting data ...");             pdialog.setindeterminate(false);             pdialog.setcancelable(true);             pdialog.show();          }          @override         protected jsonobject doinbackground(string... args) {             jsonparser jparser = new jsonparser();              // getting json url             jsonobject json = jparser.getjsonfromurl(url);             return json;         }         @override         protected void onpostexecute(jsonobject json) {             pdialog.dismiss();             try {                  // getting json array                 result = json.getjsonarray(tag_user);                 jsonobject c = result.getjsonobject(0);                   // storing  json item in variable                 string lat = c.getstring(tag_lat);                 string longt = c.getstring(tag_long);                   //set json data in textview                  tv_latitude.settext(lat);                 tv_longitude.settext(longt);              /*    double lat = c.getdouble(tag_lat);                 double longt = c.getdouble(tag_long);                  markeroptions marker = new markeroptions().position(new latlng(lat, longt)).title("point");                 googlemap.addmarker(marker);*/               } catch (jsonexception e) {                 e.printstacktrace();             }          }     } } 

why commented out code adding marker? try :

// storing  json item in variable    string lat = c.getstring(tag_lat);    string longt = c.getstring(tag_long);   //set json data in textview    tv_latitude.settext(lat);   tv_longitude.settext(longt);  //parse data double   double latd = double.parsedouble(lat);   double longtd = double.parsedouble(longt);    markeroptions marker = new markeroptions().position(new latlng(latd, longtd)).title("point");   googlemap.addmarker(marker);