java - empty map when run code in android studio -

i have problem show map, why show empty map ?! in images

i'll introduce code put key in file release/res/values/google_map_api.xml , put in debug/res/values/google_map_api.xml

<resources>     <string name="google_maps_key" translatable="false" templatemergestrategy="preserve">         aizasydci-------------hsik     </string> </resources> 

also put key in androidmanifest.xml

<meta-data             android:name="com.google.android.geo.api_key"             android:value="aizasydci-------------hsik" /> 

and code of mapactivity.java

public class mapsactivity extends appcompatactivity implements onmapreadycallback {      private googlemap mmap;      @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_maps);         // obtain supportmapfragment , notified when map ready used.         supportmapfragment mapfragment = (supportmapfragment) getsupportfragmentmanager()                 .findfragmentbyid(r.id.map);         mapfragment.getmapasync(this);     }      @override     public void onmapready(googlemap googlemap) {         mmap = googlemap;          // add marker in sydney , move camera         latlng sydney = new latlng(-34, 151);         mmap.addmarker(new markeroptions().position(sydney).title("marker in sydney"));         mmap.movecamera(cameraupdatefactory.newlatlng(sydney));     } } 

note: use mobile galaxy note not emulator of android studio.

please check permission part under manifest

<uses-permission android:name="com.google.android.providers.gsf.permission.read_gservices"/> <uses-permission android:name="android.permission.access_coarse_location"/> <uses-permission android:name="android.permission.access_fine_location"/>  <permission         android:name="com.example.map.permission.maps_receive"         android:protectionlevel="signature" /> <permission           android:name="com.example.map.permission.maps_receive"           android:protectionlevel="signature"/> <uses-permission android:name="com.example.map.permission.maps_receive"/>