Facebook facebook = new Facebook("my app id");
            try {
                facebook.setAccessToken(authToken);
                SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
                Date date = format.parse(tokenExpiration);
                facebook.setAccessExpires(date.getTime());
                Bundle params = new Bundle();
                params.putString("message", "Invite Friends!");
                facebook.dialog(mActivity, "apprequests", params, new DialogListener() {

                    @Override
                    public void onFacebookError(FacebookError e) {
                        Log.e(e.getMessage(), e);
                    }

                    @Override
                    public void onError(DialogError e) {
                        Log.e(e.getMessage(), e);
                    }

                    @Override
                    public void onComplete(Bundle values) {
                    }

                    @Override
                    public void onCancel() {
                    }
                }); .....