org.apache.camel.processor

Class StreamResequencer

java.lang.Object

org.apache.camel.support.service.BaseService

org.apache.camel.support.service.ServiceSupport

org.apache.camel.support.AsyncProcessorSupport

org.apache.camel.processor.StreamResequencer

All Implemented Interfaces:

AutoCloseable, org.apache.camel.AsyncProcessor, org.apache.camel.Navigate<org.apache.camel.Processor>, org.apache.camel.Processor, SequenceSender<org.apache.camel.Exchange>, org.apache.camel.Service, org.apache.camel.ShutdownableService, org.apache.camel.spi.HasId, org.apache.camel.spi.IdAware, org.apache.camel.spi.RouteIdAware, org.apache.camel.StatefulService, org.apache.camel.SuspendableService, org.apache.camel.Traceable

public class StreamResequencer
extends org.apache.camel.support.AsyncProcessorSupport
implements SequenceSender<org.apache.camel.Exchange>, org.apache.camel.Navigate<org.apache.camel.Processor>, org.apache.camel.Traceable, org.apache.camel.spi.IdAware, org.apache.camel.spi.RouteIdAware

A resequencer that re-orders a (continuous) stream of Exchanges. The algorithm implemented by ResequencerEngine is based on the detection of gaps in a message stream rather than on a fixed batch size. Gap detection in combination with timeouts removes the constraint of having to know the number of messages of a sequence (i.e. the batch size) in advance.

Messages must contain a unique sequence number for which a predecessor and a successor is known. For example a message with the sequence number 3 has a predecessor message with the sequence number 2 and a successor message with the sequence number 4. The message sequence 2,3,5 has a gap because the successor of 3 is missing. The resequencer therefore has to retain message 5 until message 4 arrives (or a timeout occurs).

Instances of this class poll for Exchanges from a given endpoint. Resequencing work and the delivery of messages to the next processor is done within the single polling thread.

See Also:

ResequencerEngine

Field Summary

Fields inherited from class org.apache.camel.support.service.BaseService

BUILDED, FAILED, INITIALIZED, INITIALIZING, lock, NEW, SHUTDOWN, SHUTTINGDOWN, STARTED, STARTING, status, STOPPED, STOPPING, SUSPENDED, SUSPENDING

Constructor Summary

Constructors

Constructor and Description
StreamResequencer(org.apache.camel.CamelContext camelContext, org.apache.camel.Processor processor, SequenceElementComparator<org.apache.camel.Exchange> comparator, org.apache.camel.Expression expression) Creates a new StreamResequencer instance.

Method Summary

Modifier and Type	Method and Description
protected void	doStart()
protected void	doStop()
int	getCapacity() Returns this resequencer's capacity.
org.apache.camel.spi.ExceptionHandler	getExceptionHandler() Returns this resequencer's exception handler.
org.apache.camel.Expression	getExpression()
String	getId()
org.apache.camel.Processor	getProcessor() Returns the next processor.
String	getRouteId()
long	getTimeout() Returns this resequencer's timeout.
String	getTraceLabel()
boolean	hasNext()
boolean	isIgnoreInvalidExchanges()
boolean	isRejectOld()
List<org.apache.camel.Processor>	next()
boolean	process(org.apache.camel.Exchange exchange, org.apache.camel.AsyncCallback callback)
void	sendElement(org.apache.camel.Exchange exchange) Sends the exchange to the next processor.
void	setCapacity(int capacity)
void	setDeliveryAttemptInterval(long deliveryAttemptInterval)
void	setId(String id)
void	setIgnoreInvalidExchanges(boolean ignoreInvalidExchanges) Sets whether to ignore invalid exchanges which cannot be used by this stream resequencer.
void	setRejectOld(Boolean rejectOld)
void	setRouteId(String routeId)
void	setTimeout(long timeout)
String	toString()

Methods inherited from class org.apache.camel.support.AsyncProcessorSupport

process, processAsync

Methods inherited from class org.apache.camel.support.service.BaseService

build, doBuild, doFail, doInit, doLifecycleChange, doResume, doShutdown, doSuspend, fail, getStatus, init, isBuild, isInit, isNew, isRunAllowed, isShutdown, isStarted, isStarting, isStartingOrStarted, isStopped, isStopping, isStoppingOrStopped, isSuspended, isSuspending, isSuspendingOrSuspended, resume, shutdown, start, stop, suspend

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.camel.StatefulService

getStatus, isRunAllowed, isStarted, isStarting, isStopped, isStopping, isSuspending

Methods inherited from interface org.apache.camel.SuspendableService

isSuspended, resume, suspend

Methods inherited from interface org.apache.camel.ShutdownableService

shutdown

Methods inherited from interface org.apache.camel.Service

build, close, init, start, stop

Constructor Detail

StreamResequencer

public StreamResequencer(org.apache.camel.CamelContext camelContext,
                         org.apache.camel.Processor processor,
                         SequenceElementComparator<org.apache.camel.Exchange> comparator,
                         org.apache.camel.Expression expression)

Creates a new StreamResequencer instance.

Parameters:

processor - next processor that processes re-ordered exchanges.

comparator - a sequence element comparator for exchanges.

Method Detail

getExpression

public org.apache.camel.Expression getExpression()

getExceptionHandler

public org.apache.camel.spi.ExceptionHandler getExceptionHandler()

Returns this resequencer's exception handler.

getProcessor

public org.apache.camel.Processor getProcessor()

Returns the next processor.

getCapacity

public int getCapacity()

Returns this resequencer's capacity. The capacity is the maximum number of exchanges that can be managed by this resequencer at a given point in time. If the capacity if reached, polling from the endpoint will be skipped for timeout milliseconds giving exchanges the possibility to time out and to be delivered after the waiting period.

Returns:

this resequencer's capacity.

getTimeout

public long getTimeout()

Returns this resequencer's timeout. This sets the resequencer engine's timeout via ResequencerEngine.setTimeout(long). This value is also used to define the polling timeout from the endpoint.

Returns:

this resequencer's timeout. (Processor)

See Also:

ResequencerEngine.setTimeout(long)

setCapacity

public void setCapacity(int capacity)

setTimeout

public void setTimeout(long timeout)

setDeliveryAttemptInterval

public void setDeliveryAttemptInterval(long deliveryAttemptInterval)

isIgnoreInvalidExchanges

public boolean isIgnoreInvalidExchanges()

setRejectOld

public void setRejectOld(Boolean rejectOld)

isRejectOld

public boolean isRejectOld()

setIgnoreInvalidExchanges

public void setIgnoreInvalidExchanges(boolean ignoreInvalidExchanges)

Sets whether to ignore invalid exchanges which cannot be used by this stream resequencer.

Default is false, by which an CamelExchangeException is thrown if the Exchange is invalid.

toString

public String toString()

Overrides:

toString in class Object

getTraceLabel

public String getTraceLabel()

Specified by:

getTraceLabel in interface org.apache.camel.Traceable

getId

public String getId()

Specified by:

getId in interface org.apache.camel.spi.HasId

setId

public void setId(String id)

Specified by:

setId in interface org.apache.camel.spi.IdAware

getRouteId

public String getRouteId()

Specified by:

getRouteId in interface org.apache.camel.spi.RouteIdAware

setRouteId

public void setRouteId(String routeId)

Specified by:

setRouteId in interface org.apache.camel.spi.RouteIdAware

doStart

protected void doStart()
                throws Exception

Overrides:

doStart in class org.apache.camel.support.AsyncProcessorSupport

Throws:

Exception

doStop

protected void doStop()
               throws Exception

Overrides:

doStop in class org.apache.camel.support.AsyncProcessorSupport

Throws:

Exception

sendElement

public void sendElement(org.apache.camel.Exchange exchange)
                 throws Exception

Sends the exchange to the next processor.

Specified by:

sendElement in interface SequenceSender<org.apache.camel.Exchange>

Parameters:

exchange - exchange to send.

Throws:

Exception - if delivery fails.

process

public boolean process(org.apache.camel.Exchange exchange,
                       org.apache.camel.AsyncCallback callback)

Specified by:

process in interface org.apache.camel.AsyncProcessor

hasNext

public boolean hasNext()

Specified by:

hasNext in interface org.apache.camel.Navigate<org.apache.camel.Processor>

next

public List<org.apache.camel.Processor> next()

Specified by:

next in interface org.apache.camel.Navigate<org.apache.camel.Processor>