private String getMethodType(Ros ros, String topic) { Service addTwoInts = new Service(ros, "/rosapi/topic_type", "rosapi/TopicType"); ServiceRequest request = new ServiceRequest("{\"topic\": \""+ topic +"\"}"); ServiceResponse response = addTwoInts.callServiceAndWait(request); JSONObject ob = new JSONObject(response.toString()); return ob.getString("type"); }