org.axonframework.queryhandling

Class SimpleQueryUpdateEmitter

java.lang.Object

org.axonframework.queryhandling.SimpleQueryUpdateEmitter

All Implemented Interfaces:

MessageDispatchInterceptorSupport<SubscriptionQueryUpdateMessage<?>>, QueryUpdateEmitter

public class SimpleQueryUpdateEmitter
extends Object
implements QueryUpdateEmitter

Implementation of QueryUpdateEmitter that uses Project Reactor to implement Update Handlers.

Since:

4.0

Author:

Milan Savic, Stefan Dragisic

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SimpleQueryUpdateEmitter.Builder Builder class to instantiate a SimpleQueryUpdateEmitter.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	SimpleQueryUpdateEmitter(SimpleQueryUpdateEmitter.Builder builder) Instantiate a SimpleQueryUpdateEmitter based on the fields contained in the SimpleQueryUpdateEmitter.Builder.

Method Summary

Modifier and Type	Method and Description
Set<SubscriptionQueryMessage<?,?,?>>	activeSubscriptions() Provides the set of running subscription queries.
static SimpleQueryUpdateEmitter.Builder	builder() Instantiate a Builder to be able to create a SimpleQueryUpdateEmitter.
void	complete(Predicate<SubscriptionQueryMessage<?,?,?>> filter) Completes subscription queries matching given filter.
void	completeExceptionally(Predicate<SubscriptionQueryMessage<?,?,?>> filter, Throwable cause) Completes with an error subscription queries matching given filter.
<U> void	emit(Predicate<SubscriptionQueryMessage<?,?,U>> filter, SubscriptionQueryUpdateMessage<U> update) Emits incremental update (as return value of provided update function) to subscription queries matching given filter.
boolean	queryUpdateHandlerRegistered(SubscriptionQueryMessage<?,?,?> query) Checks whether there is a query update handler for a given query.
Registration	registerDispatchInterceptor(MessageDispatchInterceptor<? super SubscriptionQueryUpdateMessage<?>> interceptor) Register the given DispatchInterceptor.
<U> UpdateHandlerRegistration<U>	registerUpdateHandler(SubscriptionQueryMessage<?,?,?> query, int updateBufferSize) Registers an Update Handler for given query with given updateBufferSize.
<U> UpdateHandlerRegistration<U>	registerUpdateHandler(SubscriptionQueryMessage<?,?,?> query, SubscriptionQueryBackpressure backpressure, int updateBufferSize) Deprecated. in favour of using {registerUpdateHandler(SubscriptionQueryMessage, int)}

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.axonframework.queryhandling.QueryUpdateEmitter

complete, completeExceptionally, emit, emit, emit

Constructor Detail

SimpleQueryUpdateEmitter

protected SimpleQueryUpdateEmitter(SimpleQueryUpdateEmitter.Builder builder)

Instantiate a SimpleQueryUpdateEmitter based on the fields contained in the SimpleQueryUpdateEmitter.Builder.

Parameters:

builder - the SimpleQueryUpdateEmitter.Builder used to instantiate a SimpleQueryUpdateEmitter instance

Method Detail

builder

public static SimpleQueryUpdateEmitter.Builder builder()

Instantiate a Builder to be able to create a SimpleQueryUpdateEmitter.

The MessageMonitor is defaulted to a NoOpMessageMonitor and the QueryBusSpanFactory defaults to a DefaultQueryBusSpanFactory backed by a NoOpSpanFactory.

Returns:

a Builder to be able to create a SimpleQueryUpdateEmitter

queryUpdateHandlerRegistered

public boolean queryUpdateHandlerRegistered(@Nonnull
                                            SubscriptionQueryMessage<?,?,?> query)

Description copied from interface: QueryUpdateEmitter

Checks whether there is a query update handler for a given query.

Specified by:

queryUpdateHandlerRegistered in interface QueryUpdateEmitter

Parameters:

query - the subscription query for which we have registered the update handler

Returns:

true if there is an update handler registered for given query, false otherwise

registerUpdateHandler

@Deprecated
public <U> UpdateHandlerRegistration<U> registerUpdateHandler(SubscriptionQueryMessage<?,?,?> query,
                                                                          SubscriptionQueryBackpressure backpressure,
                                                                          int updateBufferSize)

Deprecated. in favour of using {registerUpdateHandler(SubscriptionQueryMessage, int)}

Registers an Update Handler for given query with given backpressure and updateBufferSize.

Specified by:

registerUpdateHandler in interface QueryUpdateEmitter

Type Parameters:

U - the incremental response types of the query

Parameters:

query - the subscription query for which we register an Update Handler

backpressure - the backpressure mechanism to be used for emitting updates

updateBufferSize - the size of buffer which accumulates updates before subscription to the flux is made

Returns:

the object which contains updates and a registration which can be used to cancel them

registerUpdateHandler

public <U> UpdateHandlerRegistration<U> registerUpdateHandler(@Nonnull
                                                              SubscriptionQueryMessage<?,?,?> query,
                                                              int updateBufferSize)

Description copied from interface: QueryUpdateEmitter

Registers an Update Handler for given query with given updateBufferSize.

Specified by:

registerUpdateHandler in interface QueryUpdateEmitter

Type Parameters:

U - the incremental response types of the query

Parameters:

query - the subscription query for which we register an Update Handler

updateBufferSize - the size of buffer which accumulates updates before subscription to the flux is made

Returns:

the object which contains updates and a registration which can be used to cancel them

emit

public <U> void emit(@Nonnull
                     Predicate<SubscriptionQueryMessage<?,?,U>> filter,
                     @Nonnull
                     SubscriptionQueryUpdateMessage<U> update)

Description copied from interface: QueryUpdateEmitter

Emits incremental update (as return value of provided update function) to subscription queries matching given filter.

Specified by:

emit in interface QueryUpdateEmitter

Type Parameters:

U - the type of the update

Parameters:

filter - predicate on subscription query message used to filter subscription queries

update - incremental update message

complete

public void complete(@Nonnull
                     Predicate<SubscriptionQueryMessage<?,?,?>> filter)

Description copied from interface: QueryUpdateEmitter

Completes subscription queries matching given filter.

Specified by:

complete in interface QueryUpdateEmitter

Parameters:

filter - predicate on subscription query message used to filter subscription queries

completeExceptionally

public void completeExceptionally(@Nonnull
                                  Predicate<SubscriptionQueryMessage<?,?,?>> filter,
                                  @Nonnull
                                  Throwable cause)

Description copied from interface: QueryUpdateEmitter

Completes with an error subscription queries matching given filter.

Specified by:

completeExceptionally in interface QueryUpdateEmitter

Parameters:

filter - predicate on subscription query message used to filter subscription queries

cause - the cause of an error

registerDispatchInterceptor

@Nonnull
public Registration registerDispatchInterceptor(@Nonnull
                                                         MessageDispatchInterceptor<? super SubscriptionQueryUpdateMessage<?>> interceptor)

Description copied from interface: MessageDispatchInterceptorSupport

Register the given DispatchInterceptor. After registration, the interceptor will be invoked for each Message dispatched on the messaging component that it was registered to.

Specified by:

registerDispatchInterceptor in interface MessageDispatchInterceptorSupport<SubscriptionQueryUpdateMessage<?>>

Parameters:

interceptor - The interceptor to register

Returns:

A Registration, which may be used to deregister the interceptor.

activeSubscriptions

public Set<SubscriptionQueryMessage<?,?,?>> activeSubscriptions()

Description copied from interface: QueryUpdateEmitter

Provides the set of running subscription queries. If there are changes to subscriptions they will be reflected in the returned set of this method. Implementations should provide an unmodifiable set of the active subscriptions.

Specified by:

activeSubscriptions in interface QueryUpdateEmitter

Returns:

the set of running subscription queries