Android login with Facebook

Android login with Facebook

I have followed all the steps mentioned in the official SDK doc to use
Facebook login in my app but every time I try to login nothing happens and
the logcat console shows "Logged Out..." coming from :
private void onSessionStateChange(Session session, SessionState state,
Exception exception) {
if (state.isOpened()) {
Log.i(TAG, "Logged in...");
} else if (state.isClosed()) {
Log.i(TAG, "Logged out...");
}
}