org.axonframework.eventhandling.saga.repository.jpa

Class JpaSagaStore

java.lang.Object

org.axonframework.eventhandling.saga.repository.jpa.JpaSagaStore

All Implemented Interfaces:

SagaStore<Object>

public class JpaSagaStore
extends Object
implements SagaStore<Object>

JPA implementation of the Saga Store. It uses an EntityManager to persist the actual saga in a backing store in serialized form.

After each operations that modified the backing store, EntityManager.flush() is invoked to ensure the store contains the last modifications. To override this behavior, see setUseExplicitFlush(boolean)

Since:

3.0

Author:

Allard Buijze

Nested Class Summary

Nested classes/interfaces inherited from interface org.axonframework.eventhandling.saga.repository.SagaStore

SagaStore.Entry<T>

Constructor Summary

Constructors

Constructor and Description
JpaSagaStore(EntityManagerProvider entityManagerProvider) Initializes a Saga Repository with an XStreamSerializer and given entityManagerProvider.
JpaSagaStore(Serializer serializer, EntityManagerProvider entityManagerProvider) Initializes a Saga Repository with the given serializer and entityManagerProvider.

Method Summary

Modifier and Type	Method and Description
protected AbstractSagaEntry<?>	createSagaEntry(Object saga, String sagaIdentifier, Serializer serializer) Intended for clients to override.
void	deleteSaga(Class<?> sagaType, String sagaIdentifier, Set<AssociationValue> associationValues) Deletes a Saga with given sagaType and sagaIdentifier and all its associations.
Set<String>	findSagas(Class<?> sagaType, AssociationValue associationValue) Returns identifiers of saga instances of the given sagaType that have been associated with the given associationValue.
void	insertSaga(Class<?> sagaType, String sagaIdentifier, Object saga, TrackingToken token, Set<AssociationValue> associationValues) Adds a new Saga and its initial association values to the store.
protected Set<AssociationValue>	loadAssociationValues(javax.persistence.EntityManager entityManager, Class<?> sagaType, String sagaIdentifier) Loads the association values of the saga with given sagaIdentifier and sagaType.
<S> SagaStore.Entry<S>	loadSaga(Class<S> sagaType, String sagaIdentifier) Loads a known saga SagaStore.Entry instance with given sagaType and unique sagaIdentifier.
protected void	removeAssociationValue(javax.persistence.EntityManager entityManager, Class<?> sagaType, String sagaIdentifier, AssociationValue associationValue) Removes the given associationValue of the saga with given sagaIdentifier and sagaType.
protected String	sagaEntryEntityName() Intended for clients to override.
protected Class<? extends SimpleSerializedObject<?>>	serializedObjectType() Intended for clients to override.
void	setUseExplicitFlush(boolean useExplicitFlush) Sets whether or not to do an explicit EntityManager.flush() after each data modifying operation on the backing storage.
protected void	storeAssociationValue(javax.persistence.EntityManager entityManager, Class<?> sagaType, String sagaIdentifier, AssociationValue associationValue) Stores the given associationValue of the saga with given sagaIdentifier and sagaType.
void	updateSaga(Class<?> sagaType, String sagaIdentifier, Object saga, TrackingToken token, AssociationValues associationValues) Updates a given Saga after its state was modified.

Methods inherited from class java.lang.Object

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

Constructor Detail

JpaSagaStore

public JpaSagaStore(EntityManagerProvider entityManagerProvider)

Initializes a Saga Repository with an XStreamSerializer and given entityManagerProvider.

Parameters:

entityManagerProvider - The EntityManagerProvider providing the EntityManager instance for this repository

JpaSagaStore

public JpaSagaStore(Serializer serializer,
                    EntityManagerProvider entityManagerProvider)

Initializes a Saga Repository with the given serializer and entityManagerProvider.

Parameters:

serializer - The serializer to serialize saga instances with

entityManagerProvider - The EntityManagerProvider providing the EntityManager instance for this repository

Method Detail

loadSaga

public <S> SagaStore.Entry<S> loadSaga(Class<S> sagaType,
                                       String sagaIdentifier)

Description copied from interface: SagaStore

Loads a known saga SagaStore.Entry instance with given sagaType and unique sagaIdentifier.

Due to the concurrent nature of Sagas, it is not unlikely for a Saga to have ceased to exist after it has been found based on associations. Therefore, a repository should return null in case a Saga doesn't exists, as opposed to throwing an exception.

Specified by:

loadSaga in interface SagaStore<Object>

Parameters:

sagaType - The type of the returned saga entry

sagaIdentifier - The unique identifier of the returned saga entry

Returns:

The saga entry, or null if no such saga exists

loadAssociationValues

protected Set<AssociationValue> loadAssociationValues(javax.persistence.EntityManager entityManager,
                                                      Class<?> sagaType,
                                                      String sagaIdentifier)

Loads the association values of the saga with given sagaIdentifier and sagaType.

Parameters:

entityManager - the entity manager instance to use for the query

sagaType - the saga instance class

sagaIdentifier - the saga identifier

Returns:

the associations of the given saga

removeAssociationValue

protected void removeAssociationValue(javax.persistence.EntityManager entityManager,
                                      Class<?> sagaType,
                                      String sagaIdentifier,
                                      AssociationValue associationValue)

Removes the given associationValue of the saga with given sagaIdentifier and sagaType.

Parameters:

entityManager - the entity manager instance to use for the query

sagaType - the saga instance class

sagaIdentifier - the saga identifier

associationValue - the association value to remove

storeAssociationValue

protected void storeAssociationValue(javax.persistence.EntityManager entityManager,
                                     Class<?> sagaType,
                                     String sagaIdentifier,
                                     AssociationValue associationValue)

Stores the given associationValue of the saga with given sagaIdentifier and sagaType.

Parameters:

entityManager - the entity manager instance to use for the query

sagaType - the saga instance class

sagaIdentifier - the saga identifier

associationValue - the association value to add

findSagas

public Set<String> findSagas(Class<?> sagaType,
                             AssociationValue associationValue)

Description copied from interface: SagaStore

Returns identifiers of saga instances of the given sagaType that have been associated with the given associationValue.

Specified by:

findSagas in interface SagaStore<Object>

Parameters:

sagaType - The type of the returned sagas

associationValue - The value that the returned sagas must be associated with

Returns:

A set of identifiers of sagas having the correct type and association value

deleteSaga

public void deleteSaga(Class<?> sagaType,
                       String sagaIdentifier,
                       Set<AssociationValue> associationValues)

Description copied from interface: SagaStore

Deletes a Saga with given sagaType and sagaIdentifier and all its associations. For convenience all known association values are passed along as well, which has the advantage that the saga store is not required to keep an index of association value to saga identifier.

Specified by:

deleteSaga in interface SagaStore<Object>

Parameters:

sagaType - The type of saga to delete

sagaIdentifier - The identifier of the saga to delete

associationValues - The known associations of the saga

updateSaga

public void updateSaga(Class<?> sagaType,
                       String sagaIdentifier,
                       Object saga,
                       TrackingToken token,
                       AssociationValues associationValues)

Description copied from interface: SagaStore

Updates a given Saga after its state was modified. The tracking token of the event last handled by the Saga is also passed as a parameter. Note that the given token may be null if the Saga is not tracking the event store.

Specified by:

updateSaga in interface SagaStore<Object>

Parameters:

sagaType - The type of the Saga

sagaIdentifier - The identifier of the Saga

saga - The Saga instance

token - The tracking token of the event last handled by the Saga. May be null.

associationValues - The initial association values of the Saga

insertSaga

public void insertSaga(Class<?> sagaType,
                       String sagaIdentifier,
                       Object saga,
                       TrackingToken token,
                       Set<AssociationValue> associationValues)

Description copied from interface: SagaStore

Adds a new Saga and its initial association values to the store. The tracking token of the event last handled by the Saga (usually the event that started the Saga) is also passed as a parameter. Note that the given token may be null if the Saga is not tracking the event store.

Specified by:

insertSaga in interface SagaStore<Object>

Parameters:

sagaType - The type of the Saga

sagaIdentifier - The identifier of the Saga

saga - The Saga instance

token - The tracking token of the event last handled by the Saga. May be null.

associationValues - The initial association values of the Saga

setUseExplicitFlush

public void setUseExplicitFlush(boolean useExplicitFlush)

Sets whether or not to do an explicit EntityManager.flush() after each data modifying operation on the backing storage. Default to true

Parameters:

useExplicitFlush - true to force flush, false otherwise.

createSagaEntry

protected AbstractSagaEntry<?> createSagaEntry(Object saga,
                                               String sagaIdentifier,
                                               Serializer serializer)

Intended for clients to override. Defaults to SagaEntry.

Parameters:

sagaIdentifier - The identifier of the Saga

saga - The Saga instance

serializer - The serializer to serialize to the AbstractSagaEntry.getSerializedSaga()

Returns:

An instanceof @SagaEntry

sagaEntryEntityName

protected String sagaEntryEntityName()

Intended for clients to override. Defaults to 'SagaEntry'.

Returns:

the name of the Jpa event entity

serializedObjectType

protected Class<? extends SimpleSerializedObject<?>> serializedObjectType()

Intended for clients to override. Defaults to SerialzedSaga.class

Returns: