StrictMode error with Google Maps v2 @ Android fragment

Question

Inside one of my fragments I want to display a Google Maps service. But i get a StrictMode error:

 1899-1903/com.android.calendar E/StrictMode﹕ A resource was acquired at attached stack trace but never released. See java.io.Closeable for information on avoiding resource leaks.
java.lang.Throwable: Explicit termination method 'close' not called

I have downloaded Google Play Services, Repository and Google API in the SDK. I have set up the dependencies in my Android Studio gradle build:

dependencies {
 compile fileTree(dir: 'libs', include: ['*.jar'])
 compile 'com.android.support:support-v4:21.0.0'
 compile 'com.android.support:appcompat-v7:21.0.+'
 compile 'com.google.android.gms:play-services:6.1.+'
}

My manifest settings look like this:

...
<permission
    android:name="org.example.mapapp.permission.MAPS_RECEIVE"
    android:protectionLevel="signature" />

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="org.example.mapapp.permission.MAPS_RECIEVE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<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" />

<uses-feature
    android:glEsVersion="0x00020000"
    android:required="true" />
...
<application>
...
<meta-data
        android:name="com.google.android.gms.version"
        android:value="@integer/google_play_services_version" />
<meta-data
        android:name="com.google.android.maps.v2.API_KEY"
        android:value="myApiKey" />
...

Inside my Fragment i set it up like this:

public class MapFragment extends Fragment {
    static final LatLng HAMBURG = new LatLng(53.558, 9.927);
    static final LatLng KIEL = new LatLng(53.551, 9.993);
    private static GoogleMap map;

    @Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.fragment_layout, container, false);

    map = ((SupportMapFragment) getActivity().getFragmentManager().findFragmentById(R.id.map)).getMap();
    if (map!=null){
        Marker hamburg = map.addMarker(new MarkerOptions().position(HAMBURG)
                .title("Hamburg"));
        Marker kiel = map.addMarker(new MarkerOptions()
                .position(KIEL)
                .title("Kiel")
                .snippet("Kiel is cool")
                .icon(BitmapDescriptorFactory
                        .fromResource(R.drawable.ic_launcher)));
    }

    return rootView;
    }
}

My fragment_layout.xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >

 <fragment
    android:id="@+id/map"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    class="com.google.android.gms.maps.SupportMapFragment" />

</RelativeLayout>

Answer 1

In your line:

map = ((MapFragment) getActivity().getFragmentManager().findFragmentById(R.id.map)).getMap();

You are typecasting the getMap() into a MapFragment, but in your fragment class:

<fragment
android:id="@+id/map"
android:layout_width="match_parent"
android:layout_height="match_parent"
class="com.google.android.gms.maps.SupportMapFragment" />

You are using the class "com.google.android.gms.maps.SupportMapFragment". So you have to change the typecasting from MapFragment to SupportMapFragment