Package org.axonframework.eventsourcing

Class AbstractSnapshotter

java.lang.Object

org.axonframework.eventsourcing.AbstractSnapshotter

All Implemented Interfaces:

Snapshotter

Direct Known Subclasses:

AggregateSnapshotter

public abstract class AbstractSnapshotter
extends Object
implements Snapshotter

Abstract implementation of the Snapshotter that uses a task executor to creates snapshots. Actual snapshot creation logic should be provided by a subclass.

Since:

0.6

Author:

Allard Buijze

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	AbstractSnapshotter.Builder	Abstract Builder class to instantiate AbstractSnapshotter implementations.

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method	Description
protected abstract DomainEventMessage	createSnapshot(Class<?> aggregateType, String aggregateIdentifier, DomainEventStream eventStream)	Creates a snapshot event for an aggregate of which passed events are available in the given eventStream.
protected Runnable	createSnapshotterTask(Class<?> aggregateType, String aggregateIdentifier)	Creates an instance of a task that contains the actual snapshot creation logic.
protected EventStore	getEventStore()	Returns the event store this snapshotter uses to load domain events and store snapshot events.
protected Executor	getExecutor()	Returns the executor that executes snapshot taking tasks.
void	scheduleSnapshot(Class<?> aggregateType, String aggregateIdentifier)	Schedules snapshot taking for an aggregate with given aggregateIdentifier.

Methods inherited from class java.lang.Object

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

Constructor Details

AbstractSnapshotter

protected AbstractSnapshotter(AbstractSnapshotter.Builder builder)

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

Will assert that the EventStore is not null, and will throw an AxonConfigurationException if it is null.

Parameters:

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

Method Details

scheduleSnapshot

public void scheduleSnapshot(@Nonnull
 Class<?> aggregateType,
 @Nonnull
 String aggregateIdentifier)

Description copied from interface: Snapshotter

Schedules snapshot taking for an aggregate with given aggregateIdentifier. The implementation may choose to process this call synchronously (i.e. in the caller's thread), asynchronously, or ignore the call altogether.

Specified by:

scheduleSnapshot in interface Snapshotter

Parameters:

aggregateType - the type of the aggregate to take the snapshot for

aggregateIdentifier - The identifier of the aggregate to take the snapshot for

createSnapshotterTask

protected Runnable createSnapshotterTask(Class<?> aggregateType,
 String aggregateIdentifier)

Creates an instance of a task that contains the actual snapshot creation logic.

Parameters:

aggregateType - The type of the aggregate to create a snapshot for

aggregateIdentifier - The identifier of the aggregate to create a snapshot for

Returns:

the task containing snapshot creation logic

createSnapshot

protected abstract DomainEventMessage createSnapshot(Class<?> aggregateType,
 String aggregateIdentifier,
 DomainEventStream eventStream)

Creates a snapshot event for an aggregate of which passed events are available in the given eventStream. May return null to indicate a snapshot event is not necessary or appropriate for the given event stream.

Parameters:

aggregateType - The aggregate's type identifier

aggregateIdentifier - The identifier of the aggregate to create a snapshot for

eventStream - The event stream containing the aggregate's past events

Returns:

the snapshot event for the given events, or null if none should be stored.

getEventStore

protected EventStore getEventStore()

Returns the event store this snapshotter uses to load domain events and store snapshot events.

Returns:

the event store this snapshotter uses to load domain events and store snapshot events.

getExecutor

protected Executor getExecutor()

Returns the executor that executes snapshot taking tasks.

Returns:

the executor that executes snapshot taking tasks.