org.axonframework.eventsourcing

Class EventSourcingRepository<T>

java.lang.Object

org.axonframework.modelling.command.AbstractRepository<T,org.axonframework.modelling.command.LockAwareAggregate<T,A>>

org.axonframework.modelling.command.LockingRepository<T,EventSourcedAggregate<T>>

org.axonframework.eventsourcing.EventSourcingRepository<T>

Type Parameters:

T - The type of aggregate this repository stores

All Implemented Interfaces:

org.axonframework.messaging.ScopeAware, org.axonframework.modelling.command.Repository<T>

Direct Known Subclasses:

CachingEventSourcingRepository

public class EventSourcingRepository<T>
extends org.axonframework.modelling.command.LockingRepository<T,EventSourcedAggregate<T>>

Abstract repository implementation that allows easy implementation of an Event Sourcing mechanism. It will automatically publish new events to the given EventBus and delegate event storage to the provided EventStore.

Since:

0.1

Author:

Allard Buijze

See Also:

EventStore

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	EventSourcingRepository.Builder<T> Builder class to instantiate a EventSourcingRepository.

Field Summary

Fields inherited from class org.axonframework.modelling.command.AbstractRepository

spanFactory

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	EventSourcingRepository(EventSourcingRepository.Builder<T> builder) Instantiate a EventSourcingRepository based on the fields contained in the EventSourcingRepository.Builder.

Method Summary

Modifier and Type	Method and Description
static <T> EventSourcingRepository.Builder<T>	builder(Class<T> aggregateType) Instantiate a Builder to be able to create a EventSourcingRepository for aggregate type T.
protected EventSourcedAggregate<T>	doCreateNewForLock(Callable<T> factoryMethod)
protected void	doDeleteWithLock(EventSourcedAggregate<T> aggregate)
protected EventSourcedAggregate<T>	doLoadWithLock(String aggregateIdentifier, Long expectedVersion) Perform the actual loading of an aggregate.
protected void	doSaveWithLock(EventSourcedAggregate<T> aggregate)
AggregateFactory<T>	getAggregateFactory() Returns the factory used by this repository.
protected DomainEventStream	readEvents(String aggregateIdentifier) Reads the events for the given aggregateIdentifier from the eventStore. this method may be overridden to add pre or postprocessing to the loading of an event stream
protected void	reportIllegalState(org.axonframework.modelling.command.LockAwareAggregate<T,EventSourcedAggregate<T>> aggregate)
protected void	validateOnLoad(org.axonframework.modelling.command.Aggregate<T> aggregate, Long expectedVersion)

Methods inherited from class org.axonframework.modelling.command.LockingRepository

doCreateNew, doDelete, doLoad, doLoadOrCreate, doSave, prepareForCommit

Methods inherited from class org.axonframework.modelling.command.AbstractRepository

aggregateModel, canResolve, getAggregateType, load, load, loadOrCreate, managedAggregates, newInstance, newInstance, postDelete, postSave, send

Methods inherited from class java.lang.Object

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

Constructor Detail

EventSourcingRepository

protected EventSourcingRepository(EventSourcingRepository.Builder<T> builder)

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

A goal of the provided Builder is to create an AggregateModel specifying generic T as the aggregate type to be stored. All aggregates in this repository must be instanceOf this aggregate type. To instantiate this AggregateModel, either an AggregateModel can be provided directly or an aggregateType of type Class can be used. The latter will internally resolve to an AggregateModel. Thus, either the AggregateModel or the aggregateType should be provided. An AxonConfigurationException is thrown if these criteria are not met. The same criteria holds for the AggregateFactory. Either the AggregateFactory can be set directly or it will be instantiated internally based on the aggregateType. Hence, one of both is a hard requirement, and will also result in an AxonConfigurationException if both are missing.

Additionally, the builder will assert that the LockFactory, EventStore and SnapshotTriggerDefinition are not null, resulting in an AxonConfigurationException if for any of these this is the case. The RepositorySpanFactory is defaulted to a DefaultRepositorySpanFactory backed by a NoOpSpanFactory.

Parameters:

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

Method Detail

builder

public static <T> EventSourcingRepository.Builder<T> builder(Class<T> aggregateType)

Instantiate a Builder to be able to create a EventSourcingRepository for aggregate type T. Can also be used to instantiate a CachingEventSourcingRepository for aggregate type T. This Builder will check whether a Cache is provided. If this holds, the EventSourcingRepository.Builder.build() function returns a CachingEventSourcingRepository instead of an EventSourcingRepository.

The LockFactory is defaulted to an PessimisticLockFactory and the SnapshotTriggerDefinition to a NoSnapshotTriggerDefinition implementation. A goal of this Builder goal is to create an AggregateModel specifying generic T as the aggregate type to be stored. All aggregates in this repository must be instanceOf this aggregate type. To instantiate this AggregateModel, either an AggregateModel can be provided directly or an aggregateType of type Class can be used. The latter will internally resolve to an AggregateModel. Thus, either the AggregateModel or the aggregateType should be provided. The same criteria holds for the AggregateFactory. Either the AggregateFactory can be set directly or it will be instantiated internally based on the aggregateType. Hence, one of both is a hard requirement.

Additionally, the EventStore is a hard requirement and as such should be provided.

Returns:

a Builder to be able to create a EventSourcingRepository

doLoadWithLock

protected EventSourcedAggregate<T> doLoadWithLock(String aggregateIdentifier,
                                                  Long expectedVersion)

Perform the actual loading of an aggregate. The necessary locks have been obtained.

Specified by:

doLoadWithLock in class org.axonframework.modelling.command.LockingRepository<T,EventSourcedAggregate<T>>

Parameters:

aggregateIdentifier - the identifier of the aggregate to load

expectedVersion - The expected version of the loaded aggregate

Returns:

the fully initialized aggregate

Throws:

AggregateDeletedException - in case an aggregate existed in the past, but has been deleted

org.axonframework.modelling.command.AggregateNotFoundException - when an aggregate with the given identifier does not exist

readEvents

protected DomainEventStream readEvents(String aggregateIdentifier)

Reads the events for the given aggregateIdentifier from the eventStore. this method may be overridden to add pre or postprocessing to the loading of an event stream

Parameters:

aggregateIdentifier - the identifier of the aggregate to load

Returns:

the domain event stream for the given aggregateIdentifier, with eventStreamFilter applied if one was configured

validateOnLoad

protected void validateOnLoad(org.axonframework.modelling.command.Aggregate<T> aggregate,
                              Long expectedVersion)

Overrides:

validateOnLoad in class org.axonframework.modelling.command.AbstractRepository<T,org.axonframework.modelling.command.LockAwareAggregate<T,EventSourcedAggregate<T>>>

reportIllegalState

protected void reportIllegalState(org.axonframework.modelling.command.LockAwareAggregate<T,EventSourcedAggregate<T>> aggregate)

Overrides:

reportIllegalState in class org.axonframework.modelling.command.AbstractRepository<T,org.axonframework.modelling.command.LockAwareAggregate<T,EventSourcedAggregate<T>>>

doCreateNewForLock

protected EventSourcedAggregate<T> doCreateNewForLock(Callable<T> factoryMethod)
                                               throws Exception

Specified by:

doCreateNewForLock in class org.axonframework.modelling.command.LockingRepository<T,EventSourcedAggregate<T>>

Throws:

Exception

doSaveWithLock

protected void doSaveWithLock(EventSourcedAggregate<T> aggregate)

Specified by:

doSaveWithLock in class org.axonframework.modelling.command.LockingRepository<T,EventSourcedAggregate<T>>

doDeleteWithLock

protected void doDeleteWithLock(EventSourcedAggregate<T> aggregate)

Specified by:

doDeleteWithLock in class org.axonframework.modelling.command.LockingRepository<T,EventSourcedAggregate<T>>

getAggregateFactory

public AggregateFactory<T> getAggregateFactory()

Returns the factory used by this repository.

Returns:

the factory used by this repository