org.ikasan.framework.initiator
Class AbstractInitiator

java.lang.Object
  org.ikasan.framework.initiator.AbstractInitiator

All Implemented Interfaces:

Initiator

Direct Known Subclasses:

EventDrivenInitiatorImpl, JmsMessageDrivenInitiatorImpl, JmsMessageDrivenInitiatorImpl, QuartzStatefulScheduledDrivenInitiator, SimpleInitiator

public abstract class AbstractInitiator
extends Object
implements Initiator

Abstract base class for all existing Initiator implementations Provides implementations for the common Initiator functionality:

• Monitor registration and deregistration
• Action handling as a result of flow invocation
• Monitor notification
• Property access for:
  1. ModuleName
  2. (Initiator)Name
  3. Flow
  4. error flag
  5. retry count
  6. stopping flag

Author:

Ikasan Development Team

Field Summary

protected boolean	error Flag indicating a stoppage in error
protected ErrorLoggingService	errorLoggingService Service for logging errors in a heavyweight fashion
static String	EXCEPTION_ACTION_IMPLIED_ROLLBACK Exception action is an implied rollback message
protected IkasanExceptionHandler	exceptionHandler Handler for exceptions
protected ExcludedEventService	excludedEventService Service for excluding events
protected Set<String>	exclusions Set of ids for Events that will be immediately excluded when next encountered
protected Flow	flow Flow to be invoked by this initiator
protected String	moduleName Name of the module
protected List<MonitorListener>	monitorListeners Monitor listeners for the initiator
protected String	name Name of the initiator
protected Integer	retryCount Count of how many times this Initiator has retried
protected boolean	stopping Flag indicating that the initiator has received a stop call
static String	UNSUPPORTED_EXCLUDE_ENCONTERED Exception action is an implied rollback message

Constructor Summary

AbstractInitiator(String moduleName, String name, Flow flow, IkasanExceptionHandler exceptionHandler)
Constructor

Method Summary

void	addListener(MonitorListener monitorListener) Adds a MonitorListener to this Initiator
protected abstract void	cancelRetryCycle() Cancels retry activity
protected abstract void	completeRetryCycle() Cancel the retry activity, and resume any business as usual activity
protected void	continueRetryCycle(long delay) Template method for subclasses to selectively override
IkasanExceptionHandler	getExceptionHandler() Accessor for exceptionHandler
Set<String>	getExclusions() Accessor for exclusions
Flow	getFlow() Returns the flow that this invokes
long	getHandledEventCount()
Date	getLastEventTime()
protected abstract org.apache.log4j.Logger	getLogger() Provides access to the implementation class specific logger instance
String	getModuleName() Accessor for moduleName
List<MonitorListener>	getMonitorListeners() Accessor for monitorListeners
String	getName() The flow initiator's name.
Integer	getRetryCount() Accessor for retryCount
InitiatorState	getState() Returns the current state of the Initiator
protected void	handleAction(IkasanExceptionAction action, String eventId) Handle the returned action from the flow invocation
protected void	handleRetry(Integer maxAttempts, long delay) Handle an IkasanExceptionAction 'retry'
protected void	invokeFlow(Event event) Invoke the flow with a single Event
protected void	invokeFlow(List<Event> events) Invoke the flow with all available Events, handing exception actions as we go
boolean	isError() Is this initiator in an error state.
boolean	isStopping() Accessor for stopping flag
protected void	logError(Event event, Throwable throwable, String componentName, IkasanExceptionAction exceptionAction) Logs errors in a heavy weight fashion using an ErrorLoggingService if available
protected void	notifyMonitorListeners() Notification to all registered MonitorListener of the current state of the Initiator
void	removeListener(MonitorListener monitorListener) Removes a specified MonitorListener from this Initiator This method has no effect if the specified MonitorListener is not currently a registered listener
protected void	resume() Returns the Initiator to normal running, completes recovering if necessary
void	setErrorLoggingService(ErrorLoggingService errorLoggingService) Setter for optional ErrorLoggingService
void	setExcludedEventService(ExcludedEventService excludedEventService)
void	start() Start this initiator.
protected abstract void	startInitiator() Only the extending class knows how to start the initiator.
protected abstract void	startRetryCycle(Integer maxAttempts, long delay) Initiator needs to start a retry cycle due to an exception action.
void	stop() Stop this initiator.
protected void	stopInError() Sets the error flag before stopping the initiator by normal means
protected abstract void	stopInitiator() Only the extending class knows how to stop the initiator.
boolean	supportsExclusions() Returns true if an excludedEventService is present, and thus supports exclusions

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.ikasan.framework.initiator.Initiator

getType, isRecovering, isRunning

Field Detail

EXCEPTION_ACTION_IMPLIED_ROLLBACK

public static final String EXCEPTION_ACTION_IMPLIED_ROLLBACK

Exception action is an implied rollback message

See Also:

Constant Field Values

UNSUPPORTED_EXCLUDE_ENCONTERED

public static final String UNSUPPORTED_EXCLUDE_ENCONTERED

Exception action is an implied rollback message

See Also:

Constant Field Values

monitorListeners

protected List<MonitorListener> monitorListeners

Monitor listeners for the initiator

moduleName

protected String moduleName

Name of the module

name

protected String name

Name of the initiator

flow

protected Flow flow

Flow to be invoked by this initiator

error

protected boolean error

Flag indicating a stoppage in error

stopping

protected boolean stopping

Flag indicating that the initiator has received a stop call

retryCount

protected Integer retryCount

Count of how many times this Initiator has retried

exceptionHandler

protected IkasanExceptionHandler exceptionHandler

Handler for exceptions

errorLoggingService

protected ErrorLoggingService errorLoggingService

Service for logging errors in a heavyweight fashion

excludedEventService

protected ExcludedEventService excludedEventService

Service for excluding events

exclusions

protected Set<String> exclusions

Set of ids for Events that will be immediately excluded when next encountered

Constructor Detail

AbstractInitiator

public AbstractInitiator(String moduleName,
                         String name,
                         Flow flow,
                         IkasanExceptionHandler exceptionHandler)

Constructor

Parameters:

moduleName - The name of the module

name - The name of this initiator

flow - The name of the flow it starts

exceptionHandler -

Method Detail

addListener

public void addListener(MonitorListener monitorListener)

Adds a MonitorListener to this Initiator

Parameters:

monitorListener -

removeListener

public void removeListener(MonitorListener monitorListener)

Removes a specified MonitorListener from this Initiator This method has no effect if the specified MonitorListener is not currently a registered listener

Parameters:

monitorListener - - listener to remove

notifyMonitorListeners

protected void notifyMonitorListeners()

Notification to all registered MonitorListener of the current state of the Initiator

getExceptionHandler

public IkasanExceptionHandler getExceptionHandler()

Description copied from interface: Initiator

Accessor for exceptionHandler

Specified by:

getExceptionHandler in interface Initiator

Returns:

ExceptionHandler if any

getMonitorListeners

public List<MonitorListener> getMonitorListeners()

Accessor for monitorListeners

Returns:

List of all MonitorListeners registered with this Initiator

getState

public InitiatorState getState()

Description copied from interface: Initiator

Returns the current state of the Initiator

Specified by:

getState in interface Initiator

Returns:

InitiatorState representing the current state of the Initiators

start

public void start()
           throws InitiatorOperationException

Description copied from interface: Initiator

Start this initiator.

Specified by:

start in interface Initiator

Throws:

InitiatorOperationException - Exception if we cannot start the Initiator

stop

public void stop()
          throws InitiatorOperationException

Description copied from interface: Initiator

Stop this initiator.

Specified by:

stop in interface Initiator

Throws:

InitiatorOperationException - Exception if we cannot stop the Initiator

invokeFlow

protected void invokeFlow(List<Event> events)

Invoke the flow with all available Events, handing exception actions as we go

Parameters:

events -

logError

protected void logError(Event event,
                        Throwable throwable,
                        String componentName,
                        IkasanExceptionAction exceptionAction)

Logs errors in a heavy weight fashion using an ErrorLoggingService if available

Parameters:

event -

throwable -

componentName -

invokeFlow

protected void invokeFlow(Event event)

Invoke the flow with a single Event

Parameters:

event -

handleAction

protected void handleAction(IkasanExceptionAction action,
                            String eventId)

Handle the returned action from the flow invocation

Parameters:

action - IkasanExceptionAction to deal with

handleRetry

protected void handleRetry(Integer maxAttempts,
                           long delay)
                    throws InitiatorOperationException

Handle an IkasanExceptionAction 'retry'

Parameters:

maxAttempts - - maximum number of times to retry

delay - - time to delay between retries

Throws:

InitiatorOperationException - Exception to throw if we cannot retry

resume

protected void resume()
               throws InitiatorOperationException

Returns the Initiator to normal running, completes recovering if necessary

Throws:

InitiatorOperationException

stopInError

protected void stopInError()

Sets the error flag before stopping the initiator by normal means

getModuleName

public String getModuleName()

Accessor for moduleName

Returns:

name of the module

getRetryCount

public Integer getRetryCount()

Accessor for retryCount

Specified by:

getRetryCount in interface Initiator

Returns:

getName

public String getName()

Description copied from interface: Initiator

The flow initiator's name.

Specified by:

getName in interface Initiator

Returns:

name

getFlow

public Flow getFlow()

Description copied from interface: Initiator

Returns the flow that this invokes

Specified by:

getFlow in interface Initiator

Returns:

Flow

isError

public boolean isError()

Description copied from interface: Initiator

Is this initiator in an error state. This error state also denotes this initiator as stopped.

Specified by:

isError in interface Initiator

Returns:

boolean

isStopping

public boolean isStopping()

Accessor for stopping flag

Returns:

stopping flag

setErrorLoggingService

public void setErrorLoggingService(ErrorLoggingService errorLoggingService)

Setter for optional ErrorLoggingService

Parameters:

errorLoggingService -

getLogger

protected abstract org.apache.log4j.Logger getLogger()

Provides access to the implementation class specific logger instance

Returns:

Logger instance for the extending class

completeRetryCycle

protected abstract void completeRetryCycle()

Cancel the retry activity, and resume any business as usual activity

cancelRetryCycle

protected abstract void cancelRetryCycle()

Cancels retry activity

startInitiator

protected abstract void startInitiator()
                                throws InitiatorOperationException

Only the extending class knows how to start the initiator.

Throws:

InitiatorOperationException - Exception if we cannot start initiator

stopInitiator

protected abstract void stopInitiator()
                               throws InitiatorOperationException

Only the extending class knows how to stop the initiator.

Throws:

InitiatorOperationException - Excetpion if we cannot stop initiator

startRetryCycle

protected abstract void startRetryCycle(Integer maxAttempts,
                                        long delay)
                                 throws InitiatorOperationException

Initiator needs to start a retry cycle due to an exception action. Only the extending class has the knowledge to start a retry cycle.

Parameters:

maxAttemptss - The number of retries we allow

delay - The delay in milliseconds before we perform a retry

Throws:

InitiatorOperationException

continueRetryCycle

protected void continueRetryCycle(long delay)

Template method for subclasses to selectively override

Parameters:

delay -

setExcludedEventService

public void setExcludedEventService(ExcludedEventService excludedEventService)

Parameters:

excludedEventService - to set

supportsExclusions

public boolean supportsExclusions()

Returns true if an excludedEventService is present, and thus supports exclusions

Returns:

true if exclusions are supported by this Initiator

getExclusions

public Set<String> getExclusions()

Accessor for exclusions

Returns:

set of eventIds noted for exclusion when next encountered

getHandledEventCount

public long getHandledEventCount()

Specified by:

getHandledEventCount in interface Initiator

getLastEventTime

public Date getLastEventTime()

Specified by:

getLastEventTime in interface Initiator