Package com.framed.interop.mqtt

Interface MqttTransport

All Known Implementing Classes:

PahoMqttTransport

public interface MqttTransport

Minimal MQTT transport abstraction used by MqttService. Keeps the bridge logic independent of any particular client library, so it can be exercised with an in-memory fake in tests and backed by PahoMqttTransport in production.

Method Summary

Modifier and Type	Method	Description
void	close()	Closes the connection and releases resources.
void	connect()	Establishes the broker connection.
void	publish(String topic, byte[] payload, int qos)	Publishes a message.
void	subscribe(String topicFilter, int qos, BiConsumer<String,byte[]> handler)	Subscribes to a topic filter, delivering matching messages to handler as (topic, payload).

Method Details

connect

void connect()
      throws Exception

Establishes the broker connection.

Throws:

Exception - if the connection cannot be established

publish

void publish(String topic,
 byte[] payload,
 int qos)
      throws Exception

Publishes a message.

Parameters:

topic - the topic to publish to

payload - the message payload

qos - the MQTT quality-of-service level (0/1/2)

Throws:

Exception - if publishing fails

subscribe

void subscribe(String topicFilter,
 int qos,
 BiConsumer<String,byte[]> handler)
        throws Exception

Subscribes to a topic filter, delivering matching messages to handler as (topic, payload).

Parameters:

topicFilter - the MQTT topic filter (may contain + / # wildcards)

qos - the requested QoS

handler - receives (topic, payload) for each matching message

Throws:

Exception - if subscribing fails

close

void close()

Closes the connection and releases resources.