com.microsoft.azure.sdk.iot.device.transport.mqtt

Class Mqtt

java.lang.Object

com.microsoft.azure.sdk.iot.device.transport.mqtt.Mqtt

All Implemented Interfaces:

org.eclipse.paho.client.mqttv3.MqttCallback

Direct Known Subclasses:

MqttDeviceMethod, MqttDeviceTwin, MqttMessaging

public abstract class Mqtt
extends Object
implements org.eclipse.paho.client.mqttv3.MqttCallback

Field Summary

Fields

Modifier and Type	Field and Description
protected Object	incomingLock

Constructor Summary

Constructors

Constructor and Description
Mqtt(MqttConnection mqttConnection, IotHubListener listener, MqttMessageListener messageListener, String connectionId, Map<Integer,Message> unacknowledgedSentMessages, String deviceId) Constructor to instantiate mqtt broker connection.

Method Summary

Modifier and Type	Method and Description
protected void	connect() Method to connect to mqtt broker connection.
void	connectionLost(Throwable throwable) Event fired when the connection with the MQTT broker is lost.
void	deliveryComplete(org.eclipse.paho.client.mqttv3.IMqttDeliveryToken iMqttDeliveryToken) Event fired when the message arrived on the MQTT broker.
protected void	disconnect() Method to disconnect to mqtt broker connection.
void	messageArrived(String topic, org.eclipse.paho.client.mqttv3.MqttMessage mqttMessage) Event fired when the message arrived on the MQTT broker.
org.apache.commons.lang3.tuple.Pair<String,byte[]>	peekMessage()
protected void	publish(String publishTopic, Message message) Method to publish to mqtt broker connection.
IotHubTransportMessage	receive() Method to receive messages on mqtt broker connection.
protected boolean	sendMessageAcknowledgement(int messageId) Attempts to send ack for the provided message.
protected void	subscribe(String topic) Method to subscribe to mqtt broker connection.

Methods inherited from class java.lang.Object

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

Field Detail

incomingLock

protected final Object incomingLock

Constructor Detail

Mqtt

public Mqtt(MqttConnection mqttConnection,
            IotHubListener listener,
            MqttMessageListener messageListener,
            String connectionId,
            Map<Integer,Message> unacknowledgedSentMessages,
            String deviceId)
     throws IllegalArgumentException

Constructor to instantiate mqtt broker connection.

Parameters:

mqttConnection - the connection to use

listener - the listener to be called back upon connection established/lost and upon a message being delivered

messageListener - the listener to be called back upon a message arriving

connectionId - the id of the connection

deviceId - the Id of the device this connection belongs to

Throws:

IllegalArgumentException - if the provided mqttConnection is null

Method Detail

connect

protected void connect()
                throws TransportException

Method to connect to mqtt broker connection.

Throws:

TransportException - if failed to establish the mqtt connection.

disconnect

protected void disconnect()
                   throws TransportException

Method to disconnect to mqtt broker connection.

Throws:

TransportException - if failed to ends the mqtt connection.

publish

protected void publish(String publishTopic,
                       Message message)
                throws TransportException

Method to publish to mqtt broker connection.

Parameters:

publishTopic - the topic to publish on mqtt broker connection.

message - the message to publish.

Throws:

TransportException - if sas token has expired, if connection hasn't been established yet, or if Paho throws for any other reason

subscribe

protected void subscribe(String topic)
                  throws TransportException

Method to subscribe to mqtt broker connection.

Parameters:

topic - the topic to subscribe on mqtt broker connection.

Throws:

TransportException - if failed to subscribe the mqtt topic.

IllegalArgumentException - if topic is null

receive

public IotHubTransportMessage receive()
                               throws TransportException

Method to receive messages on mqtt broker connection.

Returns:

a received message. It can be null

Throws:

TransportException - if failed to receive mqtt message.

connectionLost

public void connectionLost(Throwable throwable)

Event fired when the connection with the MQTT broker is lost.

Specified by:

connectionLost in interface org.eclipse.paho.client.mqttv3.MqttCallback

Parameters:

throwable - Reason for losing the connection.

messageArrived

public void messageArrived(String topic,
                           org.eclipse.paho.client.mqttv3.MqttMessage mqttMessage)

Event fired when the message arrived on the MQTT broker.

Specified by:

messageArrived in interface org.eclipse.paho.client.mqttv3.MqttCallback

Parameters:

topic - the topic on which message arrived.

mqttMessage - the message arrived on the Mqtt broker.

deliveryComplete

public void deliveryComplete(org.eclipse.paho.client.mqttv3.IMqttDeliveryToken iMqttDeliveryToken)

Event fired when the message arrived on the MQTT broker.

Specified by:

deliveryComplete in interface org.eclipse.paho.client.mqttv3.MqttCallback

Parameters:

iMqttDeliveryToken - the MqttDeliveryToken for which the message was successfully sent.

peekMessage

public org.apache.commons.lang3.tuple.Pair<String,byte[]> peekMessage()

sendMessageAcknowledgement

protected boolean sendMessageAcknowledgement(int messageId)
                                      throws TransportException

Attempts to send ack for the provided message. If the message does not have a saved messageId in this layer, this function shall return false.

Parameters:

messageId - The message id to send the ack for

Returns:

true if the ack is sent successfully or false if the message isn't tied to this mqtt client

Throws:

TransportException - if an exception occurs when sending the ack