try {
            MqttClient client = new MqttClient("tcp://localhost:1884", MqttAsyncClient.generateClientId());
            client.setCallback(new MqttCallback() {
				
				@Override
				public void messageArrived(String arg0, MqttMessage arg1) throws Exception {
					log.info("messageArrived");
				}
				
				@Override
				public void deliveryComplete(IMqttDeliveryToken arg0) {
					log.info("deliveryComplete");
				}
				
				@Override
				public void connectionLost(Throwable arg0) {
					log.info("connectionLost");
				}
			}); 
MqttClient before connecting to broker
            client.connect();
            client.publish(topicName, payload, qos, true);

            String time = new Timestamp(System.currentTimeMillis()).toString();
            log.info(String.format("Publishing at:%s to Topic:%s Message:%s", time, topicName, new String(payload)));
            Thread.sleep(2000); 
            client.disconnect();
        } catch (MqttException ex) {
        	log.error(ex);
        	throw new RuntimeException(ex.getMessage());
        } catch (InterruptedException ex) {
        	log.error(ex);
        }