getting NullPointerException on Facebook Request.Callback Response

getting NullPointerException on Facebook Request.Callback Response

I am trying to execute FQL but when I try to display the response I got
NullPointerException. I followed as what written here
https://developers.facebook.com/docs/android/run-fql-queries/
below is my code.
String fql = "SELECT name,uid FROM user WHERE online_presence IN
('active', 'idle') AND uid IN ( SELECT uid2 FROM friend WHERE uid1 =
me())";
Session session = Session.getActiveSession();
if(session.isOpened()){
Bundle bundle = new Bundle();
bundle.putString("q", fql);
Request request = new Request(Session.getActiveSession(), "/fql",
bundle, HttpMethod.GET, new Request.Callback() {
@Override
public void onCompleted(Response response) {
Log.d("Result", response.toString());
}
});
Request.executeBatchAsync(request);
whole NullPointerException
09-27 19:11:09.046: E/AndroidRuntime(5134): FATAL EXCEPTION: main
09-27 19:11:09.046: E/AndroidRuntime(5134):
java.lang.NullPointerException
09-27 19:11:09.046: E/AndroidRuntime(5134): at
libcore.net.http.HttpEngine.writeRequestHeaders(HttpEngine.java:647)
09-27 19:11:09.046: E/AndroidRuntime(5134): at
libcore.net.http.HttpEngine.readResponse(HttpEngine.java:801)
09-27 19:11:09.046: E/AndroidRuntime(5134): at
libcore.net.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:293)
09-27 19:11:09.046: E/AndroidRuntime(5134): at
libcore.net.http.HttpURLConnectionImpl.getResponseCode(HttpURLConnectionImpl.java:505)
09-27 19:11:09.046: E/AndroidRuntime(5134): at
libcore.net.http.HttpsURLConnectionImpl.getResponseCode(HttpsURLConnectionImpl.java:134)
09-27 19:11:09.046: E/AndroidRuntime(5134): at
com.facebook.Response.toString(Response.java:232)
09-27 19:11:09.046: E/AndroidRuntime(5134): at
com.mier.android.fbtalksms.FBFriendsListActivity$1.onCompleted(FBFriendsListActivity.java:111)
09-27 19:11:09.046: E/AndroidRuntime(5134): at
com.facebook.Request$4.run(Request.java:1634)
09-27 19:11:09.046: E/AndroidRuntime(5134): at
android.os.Handler.handleCallback(Handler.java:615)
09-27 19:11:09.046: E/AndroidRuntime(5134): at
android.os.Handler.dispatchMessage(Handler.java:92)
09-27 19:11:09.046: E/AndroidRuntime(5134): at
android.os.Looper.loop(Looper.java:153)
09-27 19:11:09.046: E/AndroidRuntime(5134): at
android.app.ActivityThread.main(ActivityThread.java:5006)
09-27 19:11:09.046: E/AndroidRuntime(5134): at
java.lang.reflect.Method.invokeNative(Native Method)
09-27 19:11:09.046: E/AndroidRuntime(5134): at
java.lang.reflect.Method.invoke(Method.java:511)
09-27 19:11:09.046: E/AndroidRuntime(5134): at
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:821)
09-27 19:11:09.046: E/AndroidRuntime(5134): at
com.android.internal.os.ZygoteInit.main(ZygoteInit.java:584)
09-27 19:11:09.046: E/AndroidRuntime(5134): at
dalvik.system.NativeStart.main(Native Method)
still can't find the reason why response returns null
NullPointerException occurs on Log.d("Result",response.toString());
any help would be appreciated.
Thank you.