org.alfresco.bm.event

Class AbstractEventProcessor

java.lang.Object

org.alfresco.bm.event.AbstractEventProcessor

All Implemented Interfaces:

EventProcessor, org.springframework.beans.factory.Aware, org.springframework.beans.factory.BeanNameAware

Direct Known Subclasses:

AbstractEventSelectorProcessor, AuthenticatedHttpEventProcessor, CheckUserCountEventProcessor, CreateUsers, DoNothingEventProcessor, PrepareUsers, RaiseEventsEventProcessor, RenameEventProcessor, ResultBarrier

public abstract class AbstractEventProcessor
extends Object
implements EventProcessor, org.springframework.beans.factory.BeanNameAware

Basic services for the event processor implementations

Read 'good practice' notes for documenting behaviour.

Since:

1.0

Author:

Derek Hulley

Field Summary

Fields

Modifier and Type	Field and Description
protected static boolean	DEFAULT_CHART
protected static boolean	DEFAULT_PROPAGATE_SESSION_ID
protected static long	DEFAULT_WARN_DELAY
protected org.apache.commons.logging.Log	logger Resource for derived classes to use for logging

Constructor Summary

Constructors

Constructor and Description
AbstractEventProcessor() Default constructor

Method Summary

Methods

Modifier and Type	Method and Description
long	getWarnDelay() Provide a hint for the processing framework on how much time should elapse before the warnings need to be issued over the delay
boolean	isChart() Hint whether the result should be included in charts
protected abstract EventResult	processEvent(Event event) Process an event.
EventResult	processEvent(Event event, org.apache.commons.lang3.time.StopWatch stopWatch) Process an event.
void	propagateSessionId(Event event, Event nextEvent) Called by the framework after event processing and just prior to publishing an event to the event queue.
void	register() Register this instance for the event names that are handled.
protected long	resumeTimer() Continue timing the event processing
void	setBeanName(String beanName)
void	setChart(boolean chart)
void	setEventName(String eventName) Set the single event name that this processor can handle
void	setEventNames(List<String> eventNames) Set the names of the events that this processor can handle
void	setPropagateSessionId(boolean propagateSessionId) Change the default session ID propagation behaviour
void	setRegistry(EventProcessorRegistry registry) Inject the registry that this instance will register with.
void	setWarnDelay(long warnDelay)
protected long	stopTimer() Stop timing the event processing.
protected long	suspendTimer() Suspend the event processing timer.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_WARN_DELAY

protected static final long DEFAULT_WARN_DELAY

See Also:

Constant Field Values

DEFAULT_CHART

protected static final boolean DEFAULT_CHART

DEFAULT_PROPAGATE_SESSION_ID

protected static final boolean DEFAULT_PROPAGATE_SESSION_ID

logger

protected org.apache.commons.logging.Log logger

Resource for derived classes to use for logging

Constructor Detail

AbstractEventProcessor

public AbstractEventProcessor()

Default constructor

Method Detail

toString

public String toString()

Overrides:

toString in class Object

setBeanName

public void setBeanName(String beanName)

Specified by:

setBeanName in interface org.springframework.beans.factory.BeanNameAware

setEventName

public void setEventName(String eventName)

Set the single event name that this processor can handle

setEventNames

public void setEventNames(List<String> eventNames)

Set the names of the events that this processor can handle

setRegistry

public void setRegistry(EventProcessorRegistry registry)

Inject the registry that this instance will register with.

getWarnDelay

public long getWarnDelay()

Description copied from interface: EventProcessor

Provide a hint for the processing framework on how much time should elapse before the warnings need to be issued over the delay

Specified by:

getWarnDelay in interface EventProcessor

Returns:

the processing time after which an warning is logged (default DEFAULT_WARN_DELAY)

setWarnDelay

public void setWarnDelay(long warnDelay)

Parameters:

warnDelay - the time allowed for processing before a warning is logged

See Also:

getWarnDelay()

isChart

public boolean isChart()

Description copied from interface: EventProcessor

Hint whether the result should be included in charts

Specified by:

isChart in interface EventProcessor

Returns:

true if results from this processor must be included in generated charts

setChart

public void setChart(boolean chart)

Parameters:

chart - true to tag results for charting

See Also:

isChart()

setPropagateSessionId

public void setPropagateSessionId(boolean propagateSessionId)

Change the default session ID propagation behaviour

Parameters:

propagateSessionId - true to propagate session IDs to all new events otherwise false

propagateSessionId

public void propagateSessionId(Event event,
                      Event nextEvent)

Called by the framework after event processing and just prior to publishing an event to the event queue.

The default behaviour is determined by the session propagation flag but implementations can override the behaviour on a case-by-case basis.

Implementations can make use of the SessionService for creating new sessions, the details of which can then be attached to the next event(s).

Specified by:

propagateSessionId in interface EventProcessor

Parameters:

event - the original event

nextEvent - a new event (possibly one of many)

register

public void register()

Register this instance for the event names that are handled.

suspendTimer

protected long suspendTimer()

Suspend the event processing timer.

Throws:

IllegalStateException - if the timer is not running

resumeTimer

protected long resumeTimer()

Continue timing the event processing

Throws:

IllegalStateException - if the timer is is not suspended

stopTimer

protected long stopTimer()

Stop timing the event processing. This does not need to be called by derived classes.

Throws:

IllegalStateException - if the timer is is not running or suspended

processEvent

public final EventResult processEvent(Event event,
                       org.apache.commons.lang3.time.StopWatch stopWatch)
                               throws Exception

Process an event.

NOTE: All errors are treated as terminal i.e. there will be no follow-up events published. The event and result services are provided to allow event processing to be aware of previous and future work. If the service is used to modify queues, the results could be unexpected e.g. clearing the queue will not always mean that no more events will be processed.

Timing: Event processing can StopWatch.start() and StopWatch.stop() the timer to better reflect actual event processing.

The implementation overrides this method to store the StopWatch in a thread-local.

Specified by:

processEvent in interface EventProcessor

Parameters:

event - the event (along with associated data)

stopWatch - the timer that will be used or null to have one created and attached to the process automatically

Returns:

the result of the process (includes errors and next events)

Throws:

Exception

processEvent

protected abstract EventResult processEvent(Event event)
                                     throws Exception

Process an event.

NOTE: All errors are treated as terminal i.e. there will be no follow-up events published. The event and result services are provided to allow event processing to be aware of previous and future work. If the service is used to modify queues, the results could be unexpected e.g. clearing the queue will not always mean that no more events will be processed.

Timing: Where required, implementations can manually control the times recorded for event processing.

Parameters:

event - the event (along with associated data)

Returns:

the result of the process (includes errors and next events)

Throws:

Exception

See Also:

suspendTimer(), resumeTimer(), stopTimer()