java.lang.ClassNotFoundException: Didn't find class "com.google.android.gms.maps.MapFragment" -

i have checked many blogs fixing it's not working.

my main_activity.xml:

<framelayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:tools="http://schemas.android.com/tools"     android:layout_width="match_parent"     android:layout_height="match_parent" >      <linearlayout         android:layout_width="match_parent"         android:layout_height="match_parent"         android:background="#12ffff"         android:orientation="horizontal" >     </linearlayout>      <fragment         android:id="@+id/map"         android:name="com.google.android.gms.maps.mapfragment"         android:layout_width="match_parent"         android:layout_height="400dp" />  </framelayout> 

i added google_play_services_lib project.

this mainactivty.java

import android.app.activity; import android.os.bundle;  import com.google.android.gms.maps.cameraupdatefactory; import com.google.android.gms.maps.googlemap; import com.google.android.gms.maps.mapfragment; import com.google.android.gms.maps.model.latlng; import com.google.android.gms.maps.model.marker; import com.google.android.gms.maps.model.markeroptions;  public class mainactivity extends activity {        private googlemap map;      @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_main);          gpstracker mgpstracker = new gpstracker(this);         if(mgpstracker.isgpsenabled){             latlng current_location = new latlng(mgpstracker.getlatitude(), mgpstracker.getlongitude());              map = ((mapfragment) getfragmentmanager().findfragmentbyid(r.id.map)).getmap();              marker hamburg = map.addmarker(new markeroptions().position(current_location).title("you"));                      map.movecamera(cameraupdatefactory.newlatlngzoom(current_location, 15));                     map.animatecamera(cameraupdatefactory.zoomto(10), 2000, null);         }     } } 

manifest.xml:

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android"     package="my package name"     android:versioncode="1"     android:versionname="1.0" >      <uses-sdk         android:minsdkversion="11"         android:targetsdkversion="22" />      <permission         android:name="my package name.permission.maps_receive"         android:protectionlevel="signature" />      <uses-feature         android:glesversion="0x00020000"         android:required="true" />      <uses-permission android:name="my package name.permission.maps_receive" />     <uses-permission android:name="android.permission.internet" />     <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" />      <application         android:allowbackup="true"         android:icon="@drawable/ic_launcher"         android:label="@string/app_name"         android:theme="@style/apptheme" >         <activity             android:name="my package 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="aizasybrpl30vkfxrstraixkxlltf8n8gykrceo" />         <meta-data             android:name="com.google.android.gms.version"             android:value="@integer/google_play_services_version" />     </application>  </manifest> 

please tell me mistake did here.