test

Class MqttSubscribeSample

java.lang.Object

test.MqttSubscribeSample

public class MqttSubscribeSample
extends java.lang.Object

A sample application that demonstrates how to use the Paho MQTT v3.1 Client blocking API. It can be run from the command line in one of two modes: - as a publisher, sending a single message to a topic on the server - as a subscriber, listening for messages from the server There are three versions of the sample that implement the same features but do so using using different programming styles:

1. Sample (this one) which uses the API which blocks until the operation completes
2. SampleAsyncWait shows how to use the asynchronous API with waiters that block until an action completes
3. SampleAsyncCallBack shows how to use the asynchronous API where events are used to notify the application when an action completes

If the application is run with the -h parameter then info is displayed that describes all of the options / parameters.

Constructor Summary

Constructors

Constructor and Description
MqttSubscribeSample()

Method Summary

Methods

Modifier and Type	Method and Description
void	connectionLost(java.lang.Throwable cause)
void	deliveryComplete(IMqttDeliveryToken token)
static void	main(java.lang.String[] args) The main entry point of the sample.
void	messageArrived(java.lang.String topic, MqttMessage message)
void	publish(java.lang.String topicName, int qos, byte[] payload) Publish / send a message to an MQTT server
void	subscribe() Subscribe to a topic on an MQTT server Once subscribed this method waits for the messages to arrive from the server that match the subscription.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MqttSubscribeSample

public MqttSubscribeSample()
                    throws MqttException

Throws:

MqttException

Method Detail

main

public static void main(java.lang.String[] args)

The main entry point of the sample. This method handles parsing of the arguments specified on the command-line before performing the specified action.

publish

public void publish(java.lang.String topicName,
           int qos,
           byte[] payload)
             throws MqttException

Publish / send a message to an MQTT server

Parameters:

topicName - the name of the topic to publish to

qos - the quality of service to delivery the message at (0,1,2)

payload - the set of bytes to send to the MQTT server

Throws:

MqttException

subscribe

public void subscribe()
               throws MqttException

Subscribe to a topic on an MQTT server Once subscribed this method waits for the messages to arrive from the server that match the subscription. It continues listening for messages until the enter key is pressed.

Parameters:

topicName - to subscribe to (can be wild carded)

qos - the maximum quality of service to receive messages at for this subscription

Throws:

MqttException

connectionLost

public void connectionLost(java.lang.Throwable cause)

See Also:

MqttCallback#connectionLost(Throwable)

deliveryComplete

public void deliveryComplete(IMqttDeliveryToken token)

See Also:

MqttCallback#deliveryComplete(IMqttDeliveryToken)

messageArrived

public void messageArrived(java.lang.String topic,
                  MqttMessage message)
                    throws MqttException

Throws:

MqttException

See Also:

MqttCallback#messageArrived(String, MqttMessage)