java - Not showing google maps from android device -

i want add google maps. works on device. not work on other devices want work on devices. how can it? use viewpager , fragment. have apikey developersgoogle not understand how not work

fragmenta.java

public class fragmenta extends fragment {  mapview mmapview; private googlemap googlemap; view view ; textview textview; recyclerview recyclerview ; arraylist<onemlidepremler> onemlidepremler; sondepremrecycleradapter sondepremrecycleradapter;   @override public view oncreateview(layoutinflater inflater, viewgroup container, bundle savedinstancestate) {     view rootview = inflater.inflate(r.layout.son_deprem_custom, container, false);        recyclerview = rootview.findviewbyid(r.id.son_recycler);     linearlayoutmanager layoutmanager=new linearlayoutmanager(getactivity());     layoutmanager.setorientation(linearlayoutmanager.vertical);     layoutmanager.scrolltoposition(0);     recyclerview.setlayoutmanager(layoutmanager);     onemlidepremler=new arraylist<onemlidepremler>();      mmapview = (mapview) rootview.findviewbyid(r.id.mapview);     mmapview.oncreate(savedinstancestate);      mmapview.onresume(); // needed map display      try {         mapsinitializer.initialize(getactivity().getapplicationcontext());     } catch (exception e) {         e.printstacktrace();     }      mmapview.getmapasync(new onmapreadycallback() {         @override         public void onmapready(googlemap mmap) {             googlemap = mmap;           }     });      factory.getinstance().sondepremmodel().enqueue(new callback<onemlidepremmodel>() {         @override         public void onresponse(call<onemlidepremmodel> call, response<onemlidepremmodel> response) {             sondepremrecycleradapter=new sondepremrecycleradapter(response.body().data.sublist(0, 10),googlemap);              latlng latlng=new latlng(float.parsefloat(response.body().data.get(0).lat), float.parsefloat(response.body().data.get(0).lng));             googlemap.addmarker(new markeroptions().position(latlng).title("marker title").snippet("marker description"));              cameraposition cameraposition = new cameraposition.builder().target(latlng).zoom(12).build();             googlemap.animatecamera(cameraupdatefactory.newcameraposition(cameraposition));             recyclerview.setadapter(sondepremrecycleradapter);         }          @override         public void onfailure(call<onemlidepremmodel> call, throwable t) {          }     });      return rootview; }  @override public void onresume() {     super.onresume();     mmapview.onresume(); }  @override public void onpause() {     super.onpause();     mmapview.onpause(); }  @override public void ondestroy() {     super.ondestroy();     mmapview.ondestroy(); }  @override public void onlowmemory() {     super.onlowmemory();     mmapview.onlowmemory(); }  } 

son_deprem_custom.xml

         <?xml version="1.0" encoding="utf-8"?>       <linearlayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:ads="http://schemas.android.com/apk/res-auto" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent">  <framelayout     android:layout_width="match_parent"     android:layout_height="300dp"     android:id="@+id/son_frame">      <com.google.android.gms.maps.mapview         android:id="@+id/mapview"         android:layout_width="match_parent"         android:layout_height="match_parent" />  </framelayout>  <framelayout     android:layout_width="match_parent"     android:layout_height="match_parent">        <android.support.v7.widget.recyclerview         android:layout_width="match_parent"         android:layout_height="match_parent"         android:id="@+id/son_recycler">       </android.support.v7.widget.recyclerview>    </framelayout> 

androidmanifest.xml

  <?xml version="1.0" encoding="utf-8"?>     <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.yavuzoktay.deprem"> <uses-permission   android:name="com.yavuzoktay.deprem.permission.maps_receive" /> <permission android:name="com.yavuzoktay.deprem.permission.maps_receive"     android:protectionlevel="signature" /> <uses-permission android:name="android.permission.access_network_state" /> <uses-permission android:name="android.permission.internet" /> <uses-permission    android:name="com.google.android.providers.gsf.permission.read_gservices" /> <uses-permission android:name="android.permission.write_external_storage" /> <uses-permission android:name="android.permission.access_coarse_location" /> <uses-permission android:name="android.permission.access_fine_location" />  <uses-feature android:glesversion="0x00020000" android:required="true" />  <application     android:allowbackup="true"     android:icon="@drawable/depremicon2"     android:label="@string/app_name"     android:roundicon="@mipmap/ic_launcher_round"     android:supportsrtl="true"     android:theme="@style/apptheme">     <activity         android:name=".mainactivity"         android:label="@string/app_name">         <intent-filter>             <action android:name="android.intent.action.main" />              <category android:name="android.intent.category.launcher" />         </intent-filter>     </activity>          <meta-data android:name="com.google.android.maps.v2.api_key"    android:value="mykey"></meta-data>  </application>   </manifest> 

your advice important me

thank !

you don't have api key google maps

for more details, see full guide getting api key.

 <!--the api key google maps-based apis.-->             <meta-data                 android:name="com.google.android.geo.api_key"                 android:value="@string/google_maps_key" /> 

res/values/strings.xml

<?xml version="1.0" encoding="utf-8"?> <resources>     <string name="google_maps_key">yours google maps key</string> </resources>