Android: How to check if the user running your application has logged-in into Facebook?

• How to check if the user running your application has logged-in into Facebook?

public boolean isLoggedIn() {
    AccessToken accessToken = AccessToken.getCurrentAccessToken();
    if (accessToken != null) {
        GraphRequest request = GraphRequest.newMeRequest(
                accessToken,
                new GraphRequest.GraphJSONObjectCallback() {
                    @Override
                    public void onCompleted(
                            JSONObject object,
                            GraphResponse response) {
                        // success
                    }
                });
        Bundle parameters = new Bundle();
        parameters.putString("fields", "id,name,link,friends");
        request.setParameters(parameters);
        request.executeAsync();
    }
    return accessToken != null;
}