org.axonframework.messaging.unitofwork

Class CurrentUnitOfWork

java.lang.Object

org.axonframework.messaging.unitofwork.CurrentUnitOfWork

public abstract class CurrentUnitOfWork
extends Object

Default entry point to gain access to the current UnitOfWork. Components managing transactional boundaries can register and clear UnitOfWork instances, which components can use.

Since:

0.6

Author:

Allard Buijze

Method Summary

Modifier and Type	Method and Description
static void	clear(UnitOfWork<?> unitOfWork) Clears the UnitOfWork currently bound to the current thread, if that UnitOfWork is the given unitOfWork.
static void	commit() Commits the current UnitOfWork.
static MetaData	correlationData() Returns the Correlation Data attached to the current Unit of Work, or an empty MetaData instance if no Unit of Work is started.
static UnitOfWork<?>	get() Gets the UnitOfWork bound to the current thread.
static boolean	ifStarted(Consumer<UnitOfWork<?>> consumer) If a UnitOfWork is started, invokes the given consumer with the active Unit of Work.
static boolean	isStarted() Indicates whether a unit of work has already been started.
static <T> Optional<T>	map(Function<UnitOfWork<?>,T> function) If a Unit of Work is started, execute the given function on it.
static void	set(UnitOfWork<?> unitOfWork) Binds the given unitOfWork to the current thread.

Methods inherited from class java.lang.Object

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

Method Detail

isStarted

public static boolean isStarted()

Indicates whether a unit of work has already been started. This method can be used by interceptors to prevent nesting of UnitOfWork instances.

Returns:

whether a UnitOfWork has already been started.

ifStarted

public static boolean ifStarted(Consumer<UnitOfWork<?>> consumer)

If a UnitOfWork is started, invokes the given consumer with the active Unit of Work. Otherwise, it does nothing

Parameters:

consumer - The consumer to invoke if a Unit of Work is active

Returns:

true if a unit of work is active, false otherwise

map

public static <T> Optional<T> map(Function<UnitOfWork<?>,T> function)

If a Unit of Work is started, execute the given function on it. Otherwise, returns an empty Optional. Use this method when you wish to retrieve information from a Unit of Work, reverting to a default when no Unit of Work is started.

Type Parameters:

T - The type of return value expected

Parameters:

function - The function to apply to the unit of work, if present

Returns:

an optional containing the result of the function, or an empty Optional when no Unit of Work was started

Throws:

NullPointerException - when a Unit of Work is present and the function returns null

get

public static UnitOfWork<?> get()

Gets the UnitOfWork bound to the current thread. If no UnitOfWork has been started, an IllegalStateException is thrown.

To verify whether a UnitOfWork is already active, use isStarted().

Returns:

The UnitOfWork bound to the current thread.

Throws:

IllegalStateException - if no UnitOfWork is active

commit

public static void commit()

Commits the current UnitOfWork. If no UnitOfWork was started, an IllegalStateException is thrown.

Throws:

IllegalStateException - if no UnitOfWork is currently started.

See Also:

UnitOfWork.commit()

set

public static void set(UnitOfWork<?> unitOfWork)

Binds the given unitOfWork to the current thread. If other UnitOfWork instances were bound, they will be marked as inactive until the given UnitOfWork is cleared.

Parameters:

unitOfWork - The UnitOfWork to bind to the current thread.

clear

public static void clear(UnitOfWork<?> unitOfWork)

Clears the UnitOfWork currently bound to the current thread, if that UnitOfWork is the given unitOfWork.

Parameters:

unitOfWork - The UnitOfWork expected to be bound to the current thread.

Throws:

IllegalStateException - when the given UnitOfWork was not the current active UnitOfWork. This exception indicates a potentially wrong nesting of Units Of Work.

correlationData

public static MetaData correlationData()

Returns the Correlation Data attached to the current Unit of Work, or an empty MetaData instance if no Unit of Work is started.

Returns:

a MetaData instance representing the current Unit of Work's correlation data, or an empty MetaData instance if no Unit of Work is started.

See Also:

UnitOfWork.getCorrelationData()