org.apache.camel.spi

Interface UnitOfWork

All Superinterfaces:

Service

public interface UnitOfWork
extends Service

An object representing the unit of work processing an Exchange which allows the use of Synchronization hooks. This object might map one-to-one with a transaction in JPA or Spring; or might not.

Field Summary

Fields

Modifier and Type	Field and Description
static String	MDC_BREADCRUMB_ID
static String	MDC_CAMEL_CONTEXT_ID
static String	MDC_CORRELATION_ID
static String	MDC_EXCHANGE_ID
static String	MDC_MESSAGE_ID
static String	MDC_ROUTE_ID
static String	MDC_STEP_ID
static String	MDC_TRANSACTION_KEY

Method Summary

Modifier and Type	Method and Description
void	addSynchronization(Synchronization synchronization) Adds a synchronization hook
void	afterProcess(Processor processor, Exchange exchange, AsyncCallback callback, boolean doneSync) Strategy for optional work to be executed after the processing
void	afterRoute(Exchange exchange, Route route) Invoked when this unit of work is done being routed by the given route.
AsyncCallback	beforeProcess(Processor processor, Exchange exchange, AsyncCallback callback) Strategy for optional work to be execute before processing For example the org.apache.camel.impl.MDCUnitOfWork leverages this to ensure MDC is handled correctly during routing exchanges using the asynchronous routing engine.
void	beforeRoute(Exchange exchange, Route route) Invoked when this unit of work is about to be routed by the given route.
void	beginSubUnitOfWork(Exchange exchange) Begins a SubUnitOfWork, where sub (child) unit of works participate in a parent unit of work.
void	beginTransactedBy(Object key) Mark this UnitOfWork as being transacted by the given transaction key.
boolean	containsSynchronization(Synchronization synchronization) Checks if the passed synchronization hook is already part of this unit of work.
UnitOfWork	createChildUnitOfWork(Exchange childExchange) Create a child unit of work, which is associated to this unit of work as its parent.
void	done(Exchange exchange) Invoked when this unit of work has been completed, whether it has failed or completed
void	endSubUnitOfWork(Exchange exchange) Ends a SubUnitOfWork.
void	endTransactedBy(Object key) Mark this UnitOfWork as not transacted anymore by the given transaction definition.
String	getId() Returns the unique ID of this unit of work, lazily creating one if it does not yet have one
Message	getOriginalInMessage() Gets the original IN Message this Unit of Work was started with.
RouteContext	getRouteContext() Gets the RouteContext that this UnitOfWork currently is being routed through.
SubUnitOfWorkCallback	getSubUnitOfWorkCallback() Gets the SubUnitOfWorkCallback if this unit of work participates in a sub unit of work.
void	handoverSynchronization(Exchange target) Handover all the registered synchronizations to the target Exchange.
void	handoverSynchronization(Exchange target, Predicate<Synchronization> filter) Handover all the registered synchronizations to the target Exchange.
boolean	isTransacted() Are we transacted?
boolean	isTransactedBy(Object key) Are we already transacted by the given transaction key?
RouteContext	popRouteContext() When finished being routed under the current RouteContext it should be removed.
void	pushRouteContext(RouteContext routeContext) Pushes the RouteContext that this UnitOfWork currently is being routed through.
void	removeSynchronization(Synchronization synchronization) Removes a synchronization hook
void	setParentUnitOfWork(UnitOfWork parentUnitOfWork) Sets the parent unit of work.

Methods inherited from interface org.apache.camel.Service

init, start, stop

Field Detail

MDC_BREADCRUMB_ID

static final String MDC_BREADCRUMB_ID

See Also:

Constant Field Values

MDC_EXCHANGE_ID

static final String MDC_EXCHANGE_ID

See Also:

Constant Field Values

MDC_MESSAGE_ID

static final String MDC_MESSAGE_ID

See Also:

Constant Field Values

MDC_CORRELATION_ID

static final String MDC_CORRELATION_ID

See Also:

Constant Field Values

MDC_ROUTE_ID

static final String MDC_ROUTE_ID

See Also:

Constant Field Values

MDC_STEP_ID

static final String MDC_STEP_ID

See Also:

Constant Field Values

MDC_CAMEL_CONTEXT_ID

static final String MDC_CAMEL_CONTEXT_ID

See Also:

Constant Field Values

MDC_TRANSACTION_KEY

static final String MDC_TRANSACTION_KEY

See Also:

Constant Field Values

Method Detail

addSynchronization

void addSynchronization(Synchronization synchronization)

Adds a synchronization hook

Parameters:

synchronization - the hook

removeSynchronization

void removeSynchronization(Synchronization synchronization)

Removes a synchronization hook

Parameters:

synchronization - the hook

containsSynchronization

boolean containsSynchronization(Synchronization synchronization)

Checks if the passed synchronization hook is already part of this unit of work.

Parameters:

synchronization - the hook

Returns:

true, if the passed synchronization is part of this unit of work, else false

handoverSynchronization

void handoverSynchronization(Exchange target)

Handover all the registered synchronizations to the target Exchange.

This is used when a route turns into asynchronous and the Exchange that is continued and routed in the async thread should do the on completion callbacks instead of the original synchronous thread.

Parameters:

target - the target exchange

handoverSynchronization

void handoverSynchronization(Exchange target,
                             Predicate<Synchronization> filter)

Handover all the registered synchronizations to the target Exchange.

This is used when a route turns into asynchronous and the Exchange that is continued and routed in the async thread should do the on completion callbacks instead of the original synchronous thread.

Parameters:

target - the target exchange

filter - optional filter to only handover if filter returns true

done

void done(Exchange exchange)

Invoked when this unit of work has been completed, whether it has failed or completed

Parameters:

exchange - the current exchange

beforeRoute

void beforeRoute(Exchange exchange,
                 Route route)

Invoked when this unit of work is about to be routed by the given route.

Parameters:

exchange - the current exchange

route - the route

afterRoute

void afterRoute(Exchange exchange,
                Route route)

Invoked when this unit of work is done being routed by the given route.

Parameters:

exchange - the current exchange

route - the route

getId

String getId()

Returns the unique ID of this unit of work, lazily creating one if it does not yet have one

Returns:

the unique ID

getOriginalInMessage

Message getOriginalInMessage()

Gets the original IN Message this Unit of Work was started with.

The original message is only returned if the option RuntimeConfiguration.isAllowUseOriginalMessage() is enabled. If its disabled an IllegalStateException is thrown.

Returns:

the original IN Message, or null if using original message is disabled.

isTransacted

boolean isTransacted()

Are we transacted?

Returns:

true if transacted, false otherwise

isTransactedBy

boolean isTransactedBy(Object key)

Are we already transacted by the given transaction key?

Parameters:

key - the transaction key

Returns:

true if already, false otherwise

beginTransactedBy

void beginTransactedBy(Object key)

Mark this UnitOfWork as being transacted by the given transaction key.

When the transaction is completed then invoke the endTransactedBy(Object) method using the same key.

Parameters:

key - the transaction key

endTransactedBy

void endTransactedBy(Object key)

Mark this UnitOfWork as not transacted anymore by the given transaction definition.

Parameters:

key - the transaction key

getRouteContext

RouteContext getRouteContext()

Gets the RouteContext that this UnitOfWork currently is being routed through.

Notice that an Exchange can be routed through multiple routes and thus the RouteContext can change over time.

Returns:

the route context

See Also:

pushRouteContext(RouteContext), popRouteContext()

pushRouteContext

void pushRouteContext(RouteContext routeContext)

Pushes the RouteContext that this UnitOfWork currently is being routed through.

Notice that an Exchange can be routed through multiple routes and thus the RouteContext can change over time.

Parameters:

routeContext - the route context

popRouteContext

RouteContext popRouteContext()

When finished being routed under the current RouteContext it should be removed.

Returns:

the route context or null if none existed

beforeProcess

AsyncCallback beforeProcess(Processor processor,
                            Exchange exchange,
                            AsyncCallback callback)

Strategy for optional work to be execute before processing

For example the org.apache.camel.impl.MDCUnitOfWork leverages this to ensure MDC is handled correctly during routing exchanges using the asynchronous routing engine.

Parameters:

processor - the processor to be executed

exchange - the current exchange

callback - the callback

Returns:

the callback to be used (can return a wrapped callback)

afterProcess

void afterProcess(Processor processor,
                  Exchange exchange,
                  AsyncCallback callback,
                  boolean doneSync)

Strategy for optional work to be executed after the processing

Parameters:

processor - the processor executed

exchange - the current exchange

callback - the callback used

doneSync - whether the process was done synchronously or asynchronously

createChildUnitOfWork

UnitOfWork createChildUnitOfWork(Exchange childExchange)

Create a child unit of work, which is associated to this unit of work as its parent.

This is often used when EIPs need to support SubUnitOfWorks. For example a splitter, where the sub messages of the splitter all participate in the same sub unit of work. That sub unit of work then decides whether the Splitter (in general) is failed or a processed successfully.

Parameters:

childExchange - the child exchange

Returns:

the created child unit of work

See Also:

SubUnitOfWork, SubUnitOfWorkCallback

setParentUnitOfWork

void setParentUnitOfWork(UnitOfWork parentUnitOfWork)

Sets the parent unit of work.

Parameters:

parentUnitOfWork - the parent

getSubUnitOfWorkCallback

SubUnitOfWorkCallback getSubUnitOfWorkCallback()

Gets the SubUnitOfWorkCallback if this unit of work participates in a sub unit of work.

Returns:

the callback, or null if this unit of work is not part of a sub unit of work.

See Also:

beginSubUnitOfWork(org.apache.camel.Exchange)

beginSubUnitOfWork

void beginSubUnitOfWork(Exchange exchange)

Begins a SubUnitOfWork, where sub (child) unit of works participate in a parent unit of work. The SubUnitOfWork will callback to the parent unit of work using SubUnitOfWorkCallbacks.

Parameters:

exchange - the exchange

endSubUnitOfWork

void endSubUnitOfWork(Exchange exchange)

Ends a SubUnitOfWork.

The beginSubUnitOfWork(org.apache.camel.Exchange) must have been invoked prior to this operation.

Parameters:

exchange - the exchange