// prepare parameters
 String name = "myTimerName";
 String description = "this is a demo timer description";
 String mqttEndpoint = "mymqttendpoint"; // 物接入实例名
 String destTopic = "timer_send_msg_to_this_topic";
 String msg = "{\"info\": \"this message is sent by timer myTimerName, every 30 seconds\"}";
 long totalExecuteTimes = 100;
 long period = 30;   // send message every 30 seconds
 // start first time execute period seconds later
 long beginAt = System.currentTimeMillis() / 1000 + period;
 
 // construct the CreateIotTimerRequest
 CreateIotTimerRequest req = new CreateIotTimerRequest();
 req.setName(name);
 req.setDescription(description);
 req.setEndpointName(mqttEndpoint);
 req.setTopic(destTopic);
 req.setMsg(msg);
 req.setTimes(totalExecuteTimes);
 req.setPeriod(period);
 req.setBeginAt(beginAt);

 // invoke the creation
 String uuid = client.create(req).getUuid();
 // now, uuid the unique id of the timer

// uuid为创建定时器返回的唯一id，请参考创建定时器代码
client.delete(uuid);

 String name = "myTimerName_new";
 String description = "this is a demo timer description_new";
 String mqttEndpoint = "mymqttendpoint_new"; // 物接入实例名
 String destTopic = "timer_send_msg_to_this_topic_new";
 String msg = "{\"info\": \"this message is sent by timer myTimerName, every 30 seconds_new\"}";
 long totalExecuteTimes = 100 + 200;
 long period = 30 + 30;   // send message every 60 seconds

 UpdateIotTimerRequest req = new UpdateIotTimerRequest();
 req.setName(name);
 req.setDescription(description);
 req.setEndpointName(mqttEndpoint);
 req.setTopic(destTopic);
 req.setMsg(msg);
 req.setTimes(totalExecuteTimes);
 req.setPeriod(period);

 // uuid为创建定时器返回的唯一id，请参考创建定时器代码
 client.update(req, uuid);