Вы можете использовать BroadCastReceiver
в своем классе обслуживания
public class Backgroundservice implements AlarmReceiverCallback {
private Context context;
public Backgroundservice(Context context) {
this.context = context;
}
@Override
public void onAlarmReceived() {
// send broadcast from here
Intent intent = new Intent("alaram_received");
context.sendBroadcast(intent);
}
и в своей основной деятельности получать эту трансляцию.
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Register Receiver
IntentFilter intentFilter = new IntentFilter("alaram_received");
registerReceiver(alarm_receiver,intentFilter);
}
BroadcastReceiver alarm_receiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
// refresh Token
}
};
}
Счастливое кодирование.