com.hivemq.spi.callback.events

Interface BeforePublishSendCallback

All Superinterfaces:

Callback, SynchronousCallback

public interface BeforePublishSendCallback
extends SynchronousCallback

Gets called just before a PUBLISH message is sent to a client.

This callback gets called very often, be sure to have a efficient implementation.

This callback allows the modification of MQTT PUBLISH messages at the last moment before they are sent to the client.

If more than one BeforePublishSendCallback is registered, they will get called ordered by decreasing CallbackPriority. If an exception is thrown in a BeforePublishSendCallback, all pending callbacks will not be executed.

Since:

3.3

Author:

Georg Held, Christoph Schaebel

Method Summary

Methods

Modifier and Type	Method and Description
void	beforePublishSend(ModifiablePUBLISH publish, ClientData clientData)

Methods inherited from interface com.hivemq.spi.callback.SynchronousCallback

priority

Method Detail

beforePublishSend

void beforePublishSend(ModifiablePUBLISH publish,
                     ClientData clientData)
                       throws BeforePublishSendException

Parameters:

publish - A ModifiablePUBLISH that will be sent to the client or the result of BeforePublishSendCallbacks with higher CallbackPriority.

clientData - The client ClientData for the client, to which this PUBLISH will be sent to.

Throws:

BeforePublishSendException - if the underlying PUBLISH should be dropped. All pending BeforePublishSendCallbacks will not be executed.