MQTT Integration

The MQTT Connector enables the framework to interface with MQTT messaging system. The following dependency along with other HMF4J libraries imports MQTT connector:

<dependency>
    <groupId>io.github.handy-messaging-framework</groupId>
    <version>1.1.0</version>
    <artifactId>hmf4j-mqtt-connector</artifactId>
</dependency>

The system parameter in the configuration profile should be mqtt. The supported producer and consumer properties are given below:

Producer Properties

Property	Semantics	DataType
mqtt.broker.host	The hostname of the MQTT broker	String
mqtt.broker.port	The port number of the MQTT broker	Integer
mqtt.qos	Quality of Service level for message delivery	Integer
mqtt.broker.username	Username for the MQTT broker (if authentication is required)	String
mqtt.broker.password	Password for the MQTT broker (if authentication is required)	String
mqtt.clean_session.flag	Whether to start a clean session each time the client connects to the broker	Boolean
mqtt.automatic_reconnect.flag	Whether the client should automatically attempt to reconnect to the broker if it loses connection	Boolean
connection.timeout.sec	The maximum time in seconds to wait for a connection to be established with the broker	Integer

Consumer Properties

Property	Semantics	DataType
mqtt.broker.host	The hostname of the MQTT broker	String
mqtt.broker.port	The port number of the MQTT broker	Integer
mqtt.broker.username	Username for the MQTT broker (if authentication is required)	String
mqtt.broker.password	Password for the MQTT broker (if authentication is required)	String
mqtt.clean_session.flag	Whether to start a clean session each time the client connects to the broker	Boolean
mqtt.automatic_reconnect.flag	Whether the client should automatically attempt to reconnect to the broker if it loses connection	Boolean
connection.timeout.sec	The maximum time in seconds to wait for a connection to be established with the broker	Integer
max.messages.per.batch	Mandatory Handy-Messaging Framework’s dispatcher property	Integer
max.poll.duration.millis	Mandatory Handy-Messaging Framework’s dispatcher property	Integer

A sample configuration file illustrating the producer and consumer properties is given below:

hmf4j:
 profiles:
  - profileName: mqtt_profile
    system: mqtt
    consumer:
      properties:
        mqtt.broker.host: "localhost"
        mqtt.broker.port: 1883
        mqtt.clean_session.flag: true
        mqtt.automatic_reconnect.flag: true
        connection.timeout.sec: 10
        max.messages.per.batch: 3
        max.poll.duration.millis: 15000
    producer:
      properties:
        mqtt.broker.host: "localhost"
        mqtt.broker.port: 1883
        mqtt.qos: 1
        mqtt.clean_session.flag: true
        mqtt.automatic_reconnect.flag: true
        connection.timeout.sec: 10