software.amazon.awssdk.crt.mqtt

Class MqttClientConnection

java.lang.Object

software.amazon.awssdk.crt.CrtResource

software.amazon.awssdk.crt.mqtt.MqttClientConnection

All Implemented Interfaces:

AutoCloseable

public class MqttClientConnection
extends CrtResource

This class wraps aws-c-mqtt to provide the basic MQTT pub/sub functionality via the AWS Common Runtime MqttClientConnection represents a single connection from one MqttClient to an MQTT service endpoint

Nested Class Summary

Nested classes/interfaces inherited from class software.amazon.awssdk.crt.CrtResource

CrtResource.ResourceInstance

Constructor Summary

Constructors

Constructor and Description
MqttClientConnection(MqttConnectionConfig config) Constructs a new MqttClientConnection.

Method Summary

Modifier and Type	Method and Description
protected boolean	canReleaseReferencesImmediately() Determines whether a resource releases its dependencies at the same time the native handle is released or if it waits.
CompletableFuture<Boolean>	connect() Connect to the service endpoint and start a session
CompletableFuture<Void>	disconnect() Disconnects the current session
void	onMessage(java.util.function.Consumer<MqttMessage> handler) Sets a handler to be invoked whenever a message arrives, subscription or not
CompletableFuture<Integer>	publish(MqttMessage message, QualityOfService qos, boolean retain) Publishes a message to a topic
protected void	releaseNativeHandle() Frees native resources associated with this connection.
CompletableFuture<Integer>	subscribe(String topic, QualityOfService qos) Subscribes to a topic without a handler (messages will only be delivered to the OnMessage handler)
CompletableFuture<Integer>	subscribe(String topic, QualityOfService qos, java.util.function.Consumer<MqttMessage> handler) Subscribes to a topic
CompletableFuture<Integer>	unsubscribe(String topic) Unsubscribes from a topic

Methods inherited from class software.amazon.awssdk.crt.CrtResource

acquireNativeHandle, addRef, addReferenceTo, close, collectNativeResource, collectNativeResources, decRef, getNativeHandle, getResourceLogDescription, isNull, logNativeResources, releaseReferences, removeReferenceTo, setDescription, swapReferenceTo, waitForNoResources

Methods inherited from class java.lang.Object

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

Constructor Detail

MqttClientConnection

public MqttClientConnection(MqttConnectionConfig config)
                     throws MqttException

Constructs a new MqttClientConnection. Connections are reusable after being disconnected.

Parameters:

mqttClient - Mqtt client to use. Must be non-null.

clientId - Mqtt client id to use for this connection. Must be non-null.

endpoint - Endpoint to connect to. Must be non-null.

port - Port to connect on.

Throws:

MqttException - If mqttClient is null

Method Detail

releaseNativeHandle

protected void releaseNativeHandle()

Frees native resources associated with this connection.

Specified by:

releaseNativeHandle in class CrtResource

canReleaseReferencesImmediately

protected boolean canReleaseReferencesImmediately()

Determines whether a resource releases its dependencies at the same time the native handle is released or if it waits. Resources that wait are responsible for calling releaseReferences() manually.

Specified by:

canReleaseReferencesImmediately in class CrtResource

connect

public CompletableFuture<Boolean> connect()
                                   throws MqttException

Connect to the service endpoint and start a session

Returns:

Future result is true if resuming a session, false if clean session

Throws:

MqttException - If the port is out of range

disconnect

public CompletableFuture<Void> disconnect()

Disconnects the current session

Returns:

When this future completes, the disconnection is complete

subscribe

public CompletableFuture<Integer> subscribe(String topic,
                                            QualityOfService qos,
                                            java.util.function.Consumer<MqttMessage> handler)

Subscribes to a topic

Parameters:

topic - The topic to subscribe to

qos - QualityOfService for this subscription

handler - A handler which can recieve an MqttMessage when a message is published to the topic

Returns:

Future result is the packet/message id associated with the subscribe operation

subscribe

public CompletableFuture<Integer> subscribe(String topic,
                                            QualityOfService qos)

Subscribes to a topic without a handler (messages will only be delivered to the OnMessage handler)

Parameters:

topic - The topic to subscribe to

qos - QualityOfService for this subscription

Returns:

Future result is the packet/message id associated with the subscribe operation

onMessage

public void onMessage(java.util.function.Consumer<MqttMessage> handler)

Sets a handler to be invoked whenever a message arrives, subscription or not

Parameters:

handler - A handler which can receive any MqttMessage

unsubscribe

public CompletableFuture<Integer> unsubscribe(String topic)

Unsubscribes from a topic

Parameters:

topic - The topic to unsubscribe from

Returns:

Future result is the packet/message id associated with the unsubscribe operation

publish

public CompletableFuture<Integer> publish(MqttMessage message,
                                          QualityOfService qos,
                                          boolean retain)

Publishes a message to a topic

Parameters:

message - The message to publish. The message contains the topic to publish to.

qos - The QualityOfService to use for the publish operation

retain - Whether or not the message should be retained by the broker to be delivered to future subscribers

Returns:

Future value is the packet/message id associated with the publish operation