How subscribe in an RabbitMQ queue with MQTT Paho

Question

I am trying to connect from my Android app to one queue called "messages".

The producer (one webservices under AMQP protocol) is already connected, it can be check through RabbitMQ admin panel.

To connect from my Android device I am coding like this.

private void connect() throws Exception {

    this.sampleClient = new MqttClient(this.broker, this.clientId);

    MqttConnectOptions connOpts = new MqttConnectOptions();
    connOpts.setUserName("user");
    connOpts.setPassword("user".toCharArray());
    /*connOpts.setConnectionTimeout(60 * 10);
    connOpts.setKeepAliveInterval(60 * 5);*/
    connOpts.setCleanSession(true);

    this.sampleClient.connect(connOpts);

    this.sampleClient.setCallback(this);

    this.sampleClient.subscribe("messages");

    if(!this.sampleClient.isConnected()){

        System.out.println("Not Connected");
        return;
    }

    System.out.println("Connected");
}

I have tried with "amq.topic", "amq.topic.*", "amq.topic.messages", etc... But when I look in the RabbitMQ queue section "messages" is with 0 consumers, and have been set one new queue called "mqtt-subscription-Sampleqos1" automatically.

What's happening? How can I susbscribe to "messages" queue?

Answer 1

There are two important points about this question.

According with the RabbitMQ MQTT documentation: http://www.rabbitmq.com/mqtt.html

Firstly, every queues are bound automatically to amq.topic exchange by the mqtt-plugin.

Secondly, every subscriber has his own queue which look like this, mqtt-subscription-{cliend_id}{qosX} (where X is the qos level of the subscription)

Therefore, producer must to publish the message to "amq.topic" exchange, and "amq.topic.." routing-key, and receiver must to subscribe to "amq.topic.." routing-key.