Interface MqttDelivery

public interface MqttDelivery
An application delivery for one subscription. Each matching subscription has an independent acknowledgement condition.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    ack()
    Acknowledges this subscription's QoS 1 or QoS 2 delivery in AckMode.MANUAL mode.
    long
    connectionAttempt()
    Returns the number of the connection attempt that established the connection delivering this message, as ConnAck.connectionAttempt() reports it.
    boolean
    dup()
    Returns whether the broker marked the publication as a duplicate.
    TopicFilter
    filter()
    Returns the original filter of the subscription that received this delivery, including any shared group name, as Subscription.filter() returns it.
    MqttMessage
    message()
    Returns the received message, whose payload accessor returns an independent copy.

  • Method Details

    • message

      MqttMessage message()
      Returns the received message, whose payload accessor returns an independent copy.
      Returns:
      the received message, whose payload accessor returns an independent copy

    • dup

      boolean dup()
      Returns whether the broker marked the publication as a duplicate. Always false for QoS 0.
      Returns:
      whether the broker marked the publication as a duplicate

    • connectionAttempt

      long connectionAttempt()
      Returns the number of the connection attempt that established the connection delivering this message, as ConnAck.connectionAttempt() reports it. A retransmission on a later connection carries the later attempt. An application that keeps deliveries after their connection ends can tell them from the current connection's by comparing the two.
      Returns:
      the number of the connection attempt that established the connection delivering this message, as ConnAck.connectionAttempt() reports it

    • filter

      TopicFilter filter()
      Returns the original filter of the subscription that received this delivery, including any shared group name, as Subscription.filter() returns it. A handler or hand-off acceptor shared by several subscriptions can tell their deliveries apart by it, because the client reserves a filter for one subscription while it is pending, active, or awaiting removal. Deliveries that a removed subscription accepted can still run or be received after the same filter is registered again; the deliveries of both subscriptions then name that filter. A copy that reaches overlapping subscriptions becomes one delivery for each of them, each naming its own subscription. Where the client cannot tell which subscription a broker meant a copy for, as described in MqttSubscriber, this names the subscription that the copy reached.
      Returns:
      the original filter of the subscription that received this delivery, including any shared group name, as Subscription.filter() returns it

    • ack

      void ack()
      Acknowledges this subscription's QoS 1 or QoS 2 delivery in AckMode.MANUAL mode. Safe to call from any thread, including before the handler returns. Repeated calls, QoS 0, other acknowledgement modes, and calls after the receiving session ends have no effect. In a continued session, a call after connection loss records completion; the acknowledgement waits for the broker to retransmit that message on the new connection. A failure of this delivery's handler before this call, even while disconnected, stops the client under FailurePolicy.STOP, which voids later calls, or acknowledges the delivery under FailurePolicy.SKIP. A failure after this call keeps the acknowledgement. A call made before a hand-off subscription's acceptor returns counts only if the acceptor accepts the delivery. A failure that ends the connection also invalidates other deliveries whose acknowledgement condition is unmet. Their old ack() calls and handler returns cannot acknowledge a replacement after reconnecting. This does not wait for an acknowledgement write or acknowledge another subscription. A push delivery keeps its subscription capacity until its handler returns and, for QoS 1 and 2, its acknowledgement has its turn; a pull delivery releases it at this call, and a hand-off delivery released it when accepted. In each case, acknowledgements wait for other matching subscriptions and earlier QoS 1 or 2 messages; see AckMode.