org.axonframework.unitofwork

Class DefaultUnitOfWork

java.lang.Object

org.axonframework.unitofwork.NestableUnitOfWork

org.axonframework.unitofwork.DefaultUnitOfWork

All Implemented Interfaces:

UnitOfWork

public class DefaultUnitOfWork
extends NestableUnitOfWork

Implementation of the UnitOfWork that buffers all published events until it is committed. Aggregates that have not been explicitly save in their aggregates will be saved when the UnitOfWork commits.

This implementation requires a mechanism that explicitly commits or rolls back.

Since:

0.6

Author:

Allard Buijze

Constructor Summary

Constructors

Constructor and Description
DefaultUnitOfWork() Initializes a Unit of Work (without starting it) that is not bound to any transaction.
DefaultUnitOfWork(TransactionManager<?> transactionManager) Initializes a Unit of Work (without starting it) that is binds to the transaction created by the given transactionManager when the Unit of Work starts.

Method Summary

Methods

Modifier and Type	Method and Description
protected void	doCommit() Executes the logic required to commit this unit of work.
protected void	doRollback(Throwable cause) Executes the logic required to commit this unit of work.
protected void	doStart() Performs logic required when starting this UnitOfWork instance.
boolean	isTransactional() Indicates whether this UnitOfWork is bound to a transaction.
protected void	notifyListenersAfterCommit() Send a UnitOfWorkListener.afterCommit(UnitOfWork) notification to all registered listeners.
protected void	notifyListenersCleanup() Send a UnitOfWorkListener.onCleanup(UnitOfWork) notification to all registered listeners.
protected void	notifyListenersPrepareCommit() Send a UnitOfWorkListener.onPrepareCommit(UnitOfWork, java.util.Set, java.util.List) notification to all registered listeners.
protected void	notifyListenersPrepareTransactionCommit(Object transaction) Send a UnitOfWorkListener.afterCommit(UnitOfWork) notification to all registered listeners.
protected void	notifyListenersRollback(Throwable cause) Send a UnitOfWorkListener.onRollback(UnitOfWork, Throwable) notification to all registered listeners.
protected void	publishEvents() Publishes all registered events to their respective event bus.
<T extends AggregateRoot> T	registerAggregate(T aggregate, EventBus eventBus, SaveAggregateCallback<T> saveAggregateCallback) Register an aggregate with this UnitOfWork.
void	registerForPublication(EventMessage<?> event, EventBus eventBus, boolean notifyRegistrationHandlers) Register the given event for publication on the given eventBus when the unit of work is committed.
void	registerListener(UnitOfWorkListener listener) Register a listener that listens to state changes in this UnitOfWork.
protected void	registerScheduledEvents(UnitOfWork unitOfWork) Invokes when a child Unit of Work should register its scheduled events with the given unitOfWork.
protected void	saveAggregates() Saves all registered aggregates by calling their respective callbacks.
static UnitOfWork	startAndGet() Starts a new DefaultUnitOfWork instance, registering it a CurrentUnitOfWork.
static UnitOfWork	startAndGet(TransactionManager<?> transactionManager) Starts a new DefaultUnitOfWork instance using the given transactionManager to provide a backing transaction, registering it a CurrentUnitOfWork.

Methods inherited from class org.axonframework.unitofwork.NestableUnitOfWork

attachInheritedResources, attachResource, attachResource, commit, commitInnerUnitOfWork, getResource, isStarted, publishEvent, rollback, rollback, start

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultUnitOfWork

public DefaultUnitOfWork()

Initializes a Unit of Work (without starting it) that is not bound to any transaction.

DefaultUnitOfWork

public DefaultUnitOfWork(TransactionManager<?> transactionManager)

Initializes a Unit of Work (without starting it) that is binds to the transaction created by the given transactionManager when the Unit of Work starts.

Parameters:

transactionManager - The transaction manager to manage the transaction around this Unit of Work

Method Detail

startAndGet

public static UnitOfWork startAndGet()

Starts a new DefaultUnitOfWork instance, registering it a CurrentUnitOfWork. This methods returns the started UnitOfWork instance.

Note that this Unit Of Work type is not meant to be shared among different Threads. A single DefaultUnitOfWork instance should be used exclusively by the Thread that created it.

Returns:

the started UnitOfWork instance

startAndGet

public static UnitOfWork startAndGet(TransactionManager<?> transactionManager)

Starts a new DefaultUnitOfWork instance using the given transactionManager to provide a backing transaction, registering it a CurrentUnitOfWork. This methods returns the started UnitOfWork instance.

Note that this Unit Of Work type is not meant to be shared among different Threads. A single DefaultUnitOfWork instance should be used exclusively by the Thread that created it.

Parameters:

transactionManager - The transaction manager to provide the backing transaction. May be null when not using transactions.

Returns:

the started UnitOfWork instance

doStart

protected void doStart()

Description copied from class: NestableUnitOfWork

Performs logic required when starting this UnitOfWork instance.

Specified by:

doStart in class NestableUnitOfWork

isTransactional

public boolean isTransactional()

Description copied from interface: UnitOfWork

Indicates whether this UnitOfWork is bound to a transaction.

Returns:

true if this unit of work is bound to a transaction, otherwise false

doRollback

protected void doRollback(Throwable cause)

Description copied from class: NestableUnitOfWork

Executes the logic required to commit this unit of work.

Specified by:

doRollback in class NestableUnitOfWork

Parameters:

cause - the cause of the rollback

doCommit

protected void doCommit()

Description copied from class: NestableUnitOfWork

Executes the logic required to commit this unit of work.

Specified by:

doCommit in class NestableUnitOfWork

registerScheduledEvents

protected void registerScheduledEvents(UnitOfWork unitOfWork)

Description copied from class: NestableUnitOfWork

Invokes when a child Unit of Work should register its scheduled events with the given unitOfWork. Typically, the given unitOfWork is the parent of the current.

Specified by:

registerScheduledEvents in class NestableUnitOfWork

Parameters:

unitOfWork - The Unit of Work to register scheduled events with

See Also:

UnitOfWork.publishEvent(org.axonframework.domain.EventMessage, org.axonframework.eventhandling.EventBus)

registerAggregate

public <T extends AggregateRoot> T registerAggregate(T aggregate,
                                            EventBus eventBus,
                                            SaveAggregateCallback<T> saveAggregateCallback)

Description copied from interface: UnitOfWork

Register an aggregate with this UnitOfWork. These aggregates will be saved (at the latest) when the UnitOfWork is committed. This method returns the instance of the aggregate root that should be used as part of the processing in this Unit Of Work.

If an aggregate of the same type and with the same identifier has already been registered, one of two things may happen, depending on the actual implementation:

• the instance that has already been registered is returned. In which case the given saveAggregateCallback is ignored.
• an IllegalStateException is thrown to indicate an illegal attempt to register a duplicate

.

Type Parameters:

T - the type of aggregate to register

Parameters:

aggregate - The aggregate root to register in the UnitOfWork

eventBus - The event bus on which Events generated by this aggregate must be published

saveAggregateCallback - The callback that is invoked when the UnitOfWork wants to store the registered aggregate

Returns:

The actual aggregate instance to use

registerListener

public void registerListener(UnitOfWorkListener listener)

Description copied from interface: UnitOfWork

Register a listener that listens to state changes in this UnitOfWork. This typically allows components to clean up resources, such as locks, when a UnitOfWork is committed or rolled back. If a UnitOfWork is partially committed, only the listeners bound to one of the committed aggregates is notified.

Parameters:

listener - The listener to notify when the UnitOfWork's state changes.

registerForPublication

public void registerForPublication(EventMessage<?> event,
                          EventBus eventBus,
                          boolean notifyRegistrationHandlers)

Description copied from class: NestableUnitOfWork

Register the given event for publication on the given eventBus when the unit of work is committed. This method will only be invoked on the outer unit of work, as that one is responsible for maintaining the order of publication of events.

The notifyRegistrationHandlers parameter indicates whether the registration handlers should be notified of the registration of this event.

Specified by:

registerForPublication in class NestableUnitOfWork

Parameters:

event - The Event to publish

eventBus - The Event Bus to publish the Event on

notifyRegistrationHandlers - Indicates whether event registration handlers should be notified of this event

notifyListenersRollback

protected void notifyListenersRollback(Throwable cause)

Description copied from class: NestableUnitOfWork

Send a UnitOfWorkListener.onRollback(UnitOfWork, Throwable) notification to all registered listeners.

Specified by:

notifyListenersRollback in class NestableUnitOfWork

Parameters:

cause - The cause of the rollback

notifyListenersPrepareTransactionCommit

protected void notifyListenersPrepareTransactionCommit(Object transaction)

Send a UnitOfWorkListener.afterCommit(UnitOfWork) notification to all registered listeners.

Parameters:

transaction - The object representing the transaction to about to be committed

notifyListenersAfterCommit

protected void notifyListenersAfterCommit()

Send a UnitOfWorkListener.afterCommit(UnitOfWork) notification to all registered listeners.

publishEvents

protected void publishEvents()

Publishes all registered events to their respective event bus.

saveAggregates

protected void saveAggregates()

Description copied from class: NestableUnitOfWork

Saves all registered aggregates by calling their respective callbacks.

Specified by:

saveAggregates in class NestableUnitOfWork

notifyListenersPrepareCommit

protected void notifyListenersPrepareCommit()

Description copied from class: NestableUnitOfWork

Send a UnitOfWorkListener.onPrepareCommit(UnitOfWork, java.util.Set, java.util.List) notification to all registered listeners.

Specified by:

notifyListenersPrepareCommit in class NestableUnitOfWork

notifyListenersCleanup

protected void notifyListenersCleanup()

Description copied from class: NestableUnitOfWork

Send a UnitOfWorkListener.onCleanup(UnitOfWork) notification to all registered listeners. The implementation must ensure that all listeners are notified, even if one throws an exception.

Specified by:

notifyListenersCleanup in class NestableUnitOfWork