org.axonframework.eventsourcing
Class GenericEventSourcingRepository<T extends EventSourcedAggregateRoot>

java.lang.Object
  org.axonframework.repository.AbstractRepository<T>
      org.axonframework.repository.LockingRepository<T>
          org.axonframework.eventsourcing.EventSourcingRepository<T>
              org.axonframework.eventsourcing.GenericEventSourcingRepository<T>

Type Parameters:

T - The aggregate type this repository serves

All Implemented Interfaces:

AggregateFactory<T>, Repository<T>

public class GenericEventSourcingRepository<T extends EventSourcedAggregateRoot>
extends EventSourcingRepository<T>

The GenericEventSourcingRepository is a special EventSourcingRepository implementation that can act as a repository for any type of EventSourcedAggregateRoot.

There is however, a convention that these EventSourcedAggregateRoot classes must adhere to. The type must declare an accessible constructor accepting a AggregateIdentifier as single parameter. This constructor may not perform any initialization on the aggregate, other than setting the identifier.

If the constructor is not accessible (not public), and the JVM's security setting allow it, the GenericEventSourcingRepository will try to make it accessible.

Since:

0.5

Author:

Allard Buijze

Constructor Summary

GenericEventSourcingRepository(Class<T> aggregateType)
Creates a GenericEventSourcingRepository for aggregates of the given aggregateType, using the default locking strategy (optimistic locking).

GenericEventSourcingRepository(Class<T> aggregateType, LockingStrategy lockingStrategy)
Creates a GenericEventSourcingRepository for aggregates of the given aggregateType, using the given lockingStrategy.

Method Summary

String	getTypeIdentifier() Returns the simple name of the aggregate class.
T	instantiateAggregate(AggregateIdentifier aggregateIdentifier, DomainEvent firstEvent) Instantiate the aggregate using the given aggregate identifier and first event.

Methods inherited from class org.axonframework.eventsourcing.EventSourcingRepository

createAggregate, doLoad, doSaveWithLock, setConflictResolver, setEventStore, setEventStreamDecorators, setSnapshotterTrigger, validateOnLoad

Methods inherited from class org.axonframework.repository.LockingRepository

doSave, load

Methods inherited from class org.axonframework.repository.AbstractRepository

add, load, setEventBus

Methods inherited from class java.lang.Object

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

Constructor Detail

GenericEventSourcingRepository

public GenericEventSourcingRepository(Class<T> aggregateType)

Creates a GenericEventSourcingRepository for aggregates of the given aggregateType, using the default locking strategy (optimistic locking). The given type must at least provide an accessible constructor taking a UUID as single parameter.

If the constructor is not accessible, the GenericEventSourcingRepository will attempt to make it so. If JVM security restrictions don't allow that, an exception is thrown.

Parameters:

aggregateType - The type of aggregate this repository holds

Throws:

IncompatibleAggregateException - If there is no accessible constructor accepting a UUID as single parameter

GenericEventSourcingRepository

public GenericEventSourcingRepository(Class<T> aggregateType,
                                      LockingStrategy lockingStrategy)

Creates a GenericEventSourcingRepository for aggregates of the given aggregateType, using the given lockingStrategy. The given aggregate type must at least provide an accessible constructor taking a UUID as single parameter.

If the constructor is not accessible, the GenericEventSourcingRepository will attempt to make it so. If JVM security restrictions don't allow that, an exception is thrown.

Parameters:

aggregateType - The type of aggregate this repository holds

lockingStrategy - The locking strategy to use for this repository

Throws:

IncompatibleAggregateException - If there is no accessible constructor accepting a UUID as single parameter

Method Detail

getTypeIdentifier

public String getTypeIdentifier()

Returns the simple name of the aggregate class.

Returns:

the simple name of the aggregate class.

instantiateAggregate

public T instantiateAggregate(AggregateIdentifier aggregateIdentifier,
                              DomainEvent firstEvent)

Instantiate the aggregate using the given aggregate identifier and first event. The first event of the event stream is passed to allow the repository to identify the actual implementation type of the aggregate to create. The first event can be either the event that created the aggregate or, when using event sourcing, a snapshot event. In either case, the event should be designed, such that these events contain enough information to deduct the actual aggregate type.

Note that aggregate state should *not* be initialized by this method. That means, no events should be applied by a call to this method. The first event is passed to allow the implementation to base the exact type of aggregate to instantiate on that event.

Specified by:

instantiateAggregate in class EventSourcingRepository<T extends EventSourcedAggregateRoot>

Parameters:

aggregateIdentifier - the aggregate identifier of the aggregate to instantiate

firstEvent - The first event in the event stream. This is either the event generated during creation of the aggregate, or a snapshot event

Returns:

an aggregate ready for initialization using a DomainEventStream.

Throws:

IncompatibleAggregateException - if the aggregate constructor throws an exception, or if the JVM security settings prevent the GenericEventSourcingRepository from calling the constructor.