atg.service.event
Class EventHandlerRegistry

java.lang.Object
  atg.nucleus.logging.VariableArgumentApplicationLoggingImpl
      atg.nucleus.GenericService
          atg.nucleus.GenericContext
              atg.service.event.EventHandlerRegistry

All Implemented Interfaces:

NameContext, NameContextBindingEventSource, NameContextBindingListener, NameContextElement, atg.naming.NameContextPreBindingEventSource, NameResolver, AdminableService, atg.nucleus.ConfigurationListener, atg.nucleus.ConfigurationLockRegistry, ApplicationLogging, atg.nucleus.logging.ApplicationLoggingSender, atg.nucleus.logging.TraceApplicationLogging, atg.nucleus.logging.VariableArgumentApplicationLogging, ComponentNameResolver, Service, ServiceListener, java.util.EventListener, javax.servlet.ServletContext

public class EventHandlerRegistry
extends GenericContext
implements java.util.EventListener, atg.nucleus.ConfigurationListener

Central mechanism by which handlers are registered to listen to specific event channels.

The handlerPath property of the registry defines the location of properties files for handlers. The registry looks through that directory for components who extend the GenericHandler class. The registry starts these components and registers them with the event distributor to listen for events on their specified default channels.

The registry is also notified of when a components configuration is deleted or updated and should act accordingly.

Since a handler need only implement the EventChannelListener interface and not extend GenericHandler, the registry also allows other components to register themselves by calling the registerHandler() and unregisterHandler() methods.

Field Summary

static java.lang.String	CLASS_VERSION Class version string
protected static java.lang.Class	mBaseHandlerClass The base class for all registered handlers must be GenericHandler.
protected atg.service.event.EventDistributor	mDistributor The event distributor.
protected java.lang.String	mHandlerPath The Nucleus (or property path) where handlers are configured.

Fields inherited from class atg.nucleus.GenericService

SERVICE_INFO_KEY

Fields inherited from interface atg.nucleus.logging.TraceApplicationLogging

DEFAULT_LOG_TRACE_STATUS

Fields inherited from interface atg.nucleus.logging.ApplicationLogging

DEFAULT_LOG_DEBUG_STATUS, DEFAULT_LOG_ERROR_STATUS, DEFAULT_LOG_INFO_STATUS, DEFAULT_LOG_WARNING_STATUS

Constructor Summary

EventHandlerRegistry()
Empty constructor.

Method Summary

void	configurationDeleted(atg.nucleus.ConfigurationEvent e) Called whenever a Nucleus component's configuration is deleted.
void	configurationUpdated(atg.nucleus.ConfigurationEvent e) Called whenever a Nucleus component's configuration is updated.
void	doStartService() Perform any necessary initializations to startup service.
EventChannelListener[]	getActiveHandlers() Returns an array of the currently registered Handlers.
EventChannelListener[]	getChannelListeners(java.lang.String pChannelString) Returns any handlers registered to listen to the given channel.
java.lang.String[]	getChannelsForHandler(EventChannelListener pHandler) Returns a String array of the event channels currently being listened to by the specified handler.
java.lang.String[]	getChannelsForHandler(java.lang.String pHandlerName) Returns a String array of the event channels currently being listened to by the specified handler.
java.lang.String[]	getChannelSubTopics(java.lang.String pChannelString) Returns any sub-topics of the give channel.
atg.service.event.EventDistributor	getDistributor() The event distributor.
int	getHandlerCount() The number of unique registered handlers.
java.lang.String	getHandlerPath() The Nucleus (or property path) where handlers are configured.
void	refresh() Refreshes the list of active handlers, starts any handlers not already started and registers them with the distributor on thier specified default channels.
void	registerHandler(java.lang.String pChannel, EventChannelListener pHandler) Registers an EventChannelListener to listen to events on the specified event channel.
void	setDistributor(atg.service.event.EventDistributor pValue) The event distributor.
void	setHandlerPath(java.lang.String pValue) The Nucleus (or property path) where handlers are configured.
void	unregisterHandler(java.lang.String pChannel, EventChannelListener pHandler) Unregisters an EventChannelListener from listening to events on the specified event channel.

Methods inherited from class atg.nucleus.GenericContext

addNameContextBindingListener, addNameContextPreBindingListener, clearElementLock, doStopService, getAttribute, getAttributeNames, getConfigurationLock, getContext, getDocumentRoot, getElement, getElementLock, getInitParameter, getInitParameterNames, getMajorVersion, getMimeType, getMimeTyper, getMinorVersion, getNameContextBindingListeners, getNameContextPreBindingListeners, getNamedDispatcher, getPendingElement, getRealPath, getRequestDispatcher, getResource, getResourceAsStream, getResourcePaths, getServerInfo, getServlet, getServletContextName, getServletNames, getServlets, isElementBound, listElement, listElementNames, listElements, log, log, log, notifyAddedObject, notifyRemovedObject, preNotifyAddedObject, preNotifyRemovedObject, putElement, putPendingElement, removeAttribute, removeElement, removeNameContextBindingListener, removeNameContextPreBindingListener, removePendingElement, setAttribute, setDocumentRoot, setMimeTyper, startService

Methods inherited from class atg.nucleus.GenericService

addLogListener, createAdminServlet, getAbsoluteName, getAdminServlet, getLoggingForVlogging, getLogListenerCount, getLogListeners, getName, getNameContext, getNucleus, getRoot, getServiceConfiguration, getServiceInfo, isLoggingDebug, isLoggingError, isLoggingInfo, isLoggingTrace, isLoggingWarning, isRunning, logDebug, logDebug, logDebug, logError, logError, logError, logInfo, logInfo, logInfo, logTrace, logTrace, logTrace, logWarning, logWarning, logWarning, nameContextElementBound, nameContextElementUnbound, removeLogListener, resolveName, resolveName, resolveName, resolveName, sendLogEvent, setLoggingDebug, setLoggingError, setLoggingInfo, setLoggingTrace, setLoggingWarning, setNucleus, setServiceInfo, stopService

Methods inherited from class atg.nucleus.logging.VariableArgumentApplicationLoggingImpl

vlogDebug, vlogDebug, vlogDebug, vlogDebug, vlogError, vlogError, vlogError, vlogError, vlogInfo, vlogInfo, vlogInfo, vlogInfo, vlogTrace, vlogTrace, vlogTrace, vlogTrace, vlogWarning, vlogWarning, vlogWarning, vlogWarning

Methods inherited from class java.lang.Object

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

Methods inherited from interface atg.naming.NameContextElement

getName, getNameContext

Methods inherited from interface atg.naming.NameContextBindingListener

nameContextElementBound, nameContextElementUnbound

Methods inherited from interface atg.naming.NameContextElement

getName, getNameContext

Methods inherited from interface atg.naming.NameContextBindingListener

nameContextElementBound, nameContextElementUnbound

Methods inherited from interface atg.naming.NameContextElement

getName, getNameContext

Methods inherited from interface atg.naming.NameContextBindingListener

nameContextElementBound, nameContextElementUnbound

Field Detail

CLASS_VERSION

public static java.lang.String CLASS_VERSION

Class version string

mBaseHandlerClass

protected static final java.lang.Class mBaseHandlerClass

The base class for all registered handlers must be GenericHandler.

mDistributor

protected atg.service.event.EventDistributor mDistributor

The event distributor.

mHandlerPath

protected java.lang.String mHandlerPath

The Nucleus (or property path) where handlers are configured.

Constructor Detail

EventHandlerRegistry

public EventHandlerRegistry()

Empty constructor.

Method Detail

setDistributor

public void setDistributor(atg.service.event.EventDistributor pValue)

The event distributor.

getDistributor

public atg.service.event.EventDistributor getDistributor()

The event distributor.

setHandlerPath

public void setHandlerPath(java.lang.String pValue)

The Nucleus (or property path) where handlers are configured. Default value is this components nucelus path plus "/handlers/".

getHandlerPath

public java.lang.String getHandlerPath()

The Nucleus (or property path) where handlers are configured. Default value is this components nucelus path plus "/handlers/".

getHandlerCount

public int getHandlerCount()

The number of unique registered handlers.

getActiveHandlers

public EventChannelListener[] getActiveHandlers()

Returns an array of the currently registered Handlers.

doStartService

public void doStartService()
                    throws ServiceException

Perform any necessary initializations to startup service.

Overrides:

doStartService in class GenericService

Throws:

ServiceException - if the Service had a problem starting up

refresh

public void refresh()

Refreshes the list of active handlers, starts any handlers not already started and registers them with the distributor on thier specified default channels.

Note that these handlers must extend GenericHandler, otherwise they will not be started or registered. To register handlers that do not extend GenericHandler, see the registerHandler() and unregisterHandler() methods.

registerHandler

public void registerHandler(java.lang.String pChannel,
                            EventChannelListener pHandler)
                     throws EventException

Registers an EventChannelListener to listen to events on the specified event channel. Note that calling this method will not create a properties file in the registered handler directory for the supplied handler, i.e. the registry will not auto-register the handler the next time Dynamo starts.

Throws:

EventException

unregisterHandler

public void unregisterHandler(java.lang.String pChannel,
                              EventChannelListener pHandler)

Unregisters an EventChannelListener from listening to events on the specified event channel. Note that calling this method will not remove any properties files from the registered handler directory for the supplied handler.

getChannelsForHandler

public java.lang.String[] getChannelsForHandler(EventChannelListener pHandler)

Returns a String array of the event channels currently being listened to by the specified handler. Returns null if the handler is listening to no channels.

getChannelsForHandler

public java.lang.String[] getChannelsForHandler(java.lang.String pHandlerName)

Returns a String array of the event channels currently being listened to by the specified handler. Returns null if the handler is listening to no channels.

getChannelSubTopics

public java.lang.String[] getChannelSubTopics(java.lang.String pChannelString)

Returns any sub-topics of the give channel. Note that the topics are returned as complete channel strings.

getChannelListeners

public EventChannelListener[] getChannelListeners(java.lang.String pChannelString)

Returns any handlers registered to listen to the given channel. If there are no handlers, null is returned.

configurationDeleted

public void configurationDeleted(atg.nucleus.ConfigurationEvent e)

Called whenever a Nucleus component's configuration is deleted. We check to see if it is one of our handlers and refresh accordingly.

Specified by:

configurationDeleted in interface atg.nucleus.ConfigurationListener

configurationUpdated

public void configurationUpdated(atg.nucleus.ConfigurationEvent e)

Called whenever a Nucleus component's configuration is updated. We check to see if it is one of our handlers and refresh accordingly.

Specified by:

configurationUpdated in interface atg.nucleus.ConfigurationListener