Package org.eclipse.ditto.client.registration

Interface ThingChangeRegistration

All Superinterfaces:

HandlerDeregistration

All Known Subinterfaces:

CommonManagement<T,F>, Live, LiveThingHandle, ThingHandle<F>, Twin, TwinThingHandle

All Known Implementing Classes:

CommonManagementImpl, LiveImpl, LiveThingHandleImpl, ThingHandleImpl, TwinImpl, TwinThingHandleImpl

public interface ThingChangeRegistration
extends HandlerDeregistration

Provides the functionality for registering handlers which are notified about Thing changes.

Since:

1.0.0

Method Summary

Modifier and Type	Method	Description
void	registerForThingChanges(java.lang.String registrationId, java.util.function.Consumer<ThingChange> handler)	Registers a Consumer which is notified about ThingChanges.

Methods inherited from interface org.eclipse.ditto.client.registration.HandlerDeregistration

deregister

Method Detail

registerForThingChanges

void registerForThingChanges(java.lang.String registrationId,
                             java.util.function.Consumer<ThingChange> handler)

Registers a Consumer which is notified about ThingChanges.

If registered for a specific Thing, it will only be notified of changes of that specific Thing. Otherwise, it will receive changes of all Things.

Example:

 DittoClient client = ...
 ThingHandle myThing = client.twin().forId("myThing");

 myThing.registerForThingChanges(HANDLER_ID, thingChange -> LOGGER.info("change received: {}", thingChange));
 

Parameters:

registrationId - an arbitrary ID provided by the user which can be used to cancel the registration later on. The registrationId needs to be unique per DittoClient instance.

handler - the Consumer to handle change notifications.

Throws:

DuplicateRegistrationIdException - if a handler is already registered for the given registrationId.