Package org.axonframework.axonserver.connector.event.axon

Class AxonServerEventStore

java.lang.Object

org.axonframework.eventhandling.AbstractEventBus

org.axonframework.eventsourcing.eventstore.AbstractEventStore

org.axonframework.axonserver.connector.event.axon.AxonServerEventStore

All Implemented Interfaces:

DomainEventSequenceAware, EventBus, EventStore, MessageDispatchInterceptorSupport<EventMessage<?>>, StreamableMessageSource<TrackedEventMessage<?>>, SubscribableMessageSource<EventMessage<?>>

public class AxonServerEventStore
extends AbstractEventStore

Axon EventStore implementation that connects to the AxonIQ AxonServer Server to store and retrieve Events.

Since:

4.0

Author:

Zoltan Altfatter, Marc Gathier, Allard Buijze

Nested Class Summary

Nested Classes

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

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method	Description
static AxonServerEventStore.Builder	builder()	Instantiate a Builder to be able to create a AxonServerEventStore.
StreamableMessageSource<TrackedEventMessage<?>>	createStreamableMessageSourceForContext(String context)	Creates a StreamableMessageSource that streams events from the given context, rather than the default context the application was configured to connect to.
protected Optional<DomainEventMessage<?>>	handleSnapshotReadingError(String aggregateIdentifier, Throwable e)	Invoked when an error (Exception or LinkageError) occurs while attempting to read a snapshot event.
TrackingEventStream	openStream(TrackingToken trackingToken)	Open a stream containing all messages since given tracking token.
QueryResultStream	query(String query, boolean liveUpdates)
DomainEventStream	readEvents(String aggregateIdentifier)	Open an event stream containing all domain events belonging to the given aggregateIdentifier.
protected org.axonframework.axonserver.connector.event.axon.AxonServerEventStore.AxonIQEventStorageEngine	storageEngine()	Returns the EventStorageEngine used by the event store.

Methods inherited from class org.axonframework.eventsourcing.eventstore.AbstractEventStore

createHeadToken, createTailToken, createTokenAt, lastSequenceNumberFor, prepareCommit, readEvents, stagedDomainEventMessages, storeSnapshot

Methods inherited from class org.axonframework.eventhandling.AbstractEventBus

afterCommit, commit, intercept, publish, queuedMessages, registerDispatchInterceptor, subscribe

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.axonframework.eventhandling.EventBus

publish, publish

Methods inherited from interface org.axonframework.messaging.MessageDispatchInterceptorSupport

registerDispatchInterceptor

Methods inherited from interface org.axonframework.messaging.StreamableMessageSource

createTokenSince

Methods inherited from interface org.axonframework.messaging.SubscribableMessageSource

subscribe

Constructor Details

AxonServerEventStore

protected AxonServerEventStore(AxonServerEventStore.Builder builder)

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

Will assert that the EventStorageEngine is set. If not, the AxonServerConfiguration and AxonServerConnectionManager should minimally be provided to create an AxonServer specific EventStorageEngine implementation. If either of these null assertions fail, an AxonConfigurationException will be thrown.

Parameters:

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

Method Details

builder

public static AxonServerEventStore.Builder builder()

Instantiate a Builder to be able to create a AxonServerEventStore.

The main goal of this Builder is to instantiate an AxonServer specific EventStorageEngine. The properties which may be provided through this Builder are thus all used to end up with that EventStorageEngine implementation. An EventStorageEngine may be provided directly however, although we encourage the usage of the AxonServerEventStore.Builder.configuration and AxonServerEventStore.Builder.axonServerConnectionManager functions to let it be created.

The EventUpcaster is defaulted to a NoOpEventUpcaster and the EventBusSpanFactory is defaulted to a DefaultEventBusSpanFactory backed by a NoOpSpanFactory.

The event and snapshot Serializer, AxonServerConfiguration and AxonServerConnectionManager are hard requirements if no EventStorageEngine is provided directly.

Returns:

a Builder to be able to create a AxonServerEventStore

openStream

public TrackingEventStream openStream(TrackingToken trackingToken)

Description copied from interface: StreamableMessageSource

Open a stream containing all messages since given tracking token. Pass a trackingToken of null to open a stream containing all available messages. Note that the returned stream is infinite, so beware of applying terminal operations to the returned stream.

Parameters:

trackingToken - object containing the position in the stream or null to open a stream containing all messages

Returns:

a stream of messages since the given trackingToken

query

public QueryResultStream query(String query,
 boolean liveUpdates)

storageEngine

protected org.axonframework.axonserver.connector.event.axon.AxonServerEventStore.AxonIQEventStorageEngine storageEngine()

Description copied from class: AbstractEventStore

Returns the EventStorageEngine used by the event store.

Overrides:

storageEngine in class AbstractEventStore

Returns:

The event storage engine used by this event store

createStreamableMessageSourceForContext

public StreamableMessageSource<TrackedEventMessage<?>> createStreamableMessageSourceForContext(String context)

Creates a StreamableMessageSource that streams events from the given context, rather than the default context the application was configured to connect to.

Parameters:

context - the name of the context to create a message source for

Returns:

a StreamableMessageSource of TrackedEventMessages tied to the given context

handleSnapshotReadingError

protected Optional<DomainEventMessage<?>> handleSnapshotReadingError(String aggregateIdentifier,
 Throwable e)

Description copied from class: AbstractEventStore

Invoked when an error (Exception or LinkageError) occurs while attempting to read a snapshot event. This method can be overridden to change the default behavior, which is to log the exception (warn level) and ignore the snapshot.

Overriding implementations may choose to return normally, or raise an exception. Exceptions raised from this method are propagated to the caller of the AbstractEventStore.readEvents(String) or AbstractEventStore.readEvents(String, long) methods.

Returning an empty Optional will force the initialization of the aggregate to happen based on the entire event stream of that aggregate.

Overrides:

handleSnapshotReadingError in class AbstractEventStore

Parameters:

aggregateIdentifier - The identifier of the aggregate for which an snapshot failed to load

e - The exception or error that occurred while loading or deserializing the snapshot

Returns:

An optional DomainEventMessage to use as the snapshot for this aggregate

readEvents

public DomainEventStream readEvents(String aggregateIdentifier)

Description copied from class: AbstractEventStore

Open an event stream containing all domain events belonging to the given aggregateIdentifier.

The returned stream is finite, ending with the last known event of the aggregate. If the event store holds no events of the given aggregate an empty stream is returned.

This implementation returns a DomainEventStream starting with the last stored snapshot of the aggregate followed by subsequent domain events.

Specified by:

readEvents in interface EventStore

Overrides:

readEvents in class AbstractEventStore

Parameters:

aggregateIdentifier - the identifier of the aggregate whose events to fetch

Returns:

a stream of all currently stored events of the aggregate