com.sapportals.wcm.util.events

Interface IEventBroker

All Known Subinterfaces:

IResourceEventBroker, ITransactionalEventBroker

All Known Implementing Classes:

OverallResourceEventBroker

public interface IEventBroker

The event broker is a mediator between event senders (IEventSender) and receivers (IEventReceiver). All senders and receivers must register themselfs with a broker. All receivers will receive events from all senders but it is possible to register for different event "templates" (event class and type). Usually a sender will instanciate its own broker and register itself.

Copyright (c) SAP AG 2001-2002

Field Summary

static int	PRIO_MAX
static int	PRIO_MIN

Method Summary

IEventList	clearHoldEvents(IEventReceiver receiver)
IEventList	getEvents()
IEventList	getHoldEvents(IEventReceiver receiver)
SenderMode	getMode(IEventReceiver receiver)
void	hold(IEventReceiver receiver, boolean collect)
void	register(IEventReceiver receiver, IEvent template) Registers an event receiver.
void	register(IEventReceiver receiver, IEvent template, IEventMapper mapping) See the general contract of the register(IEventReceiver, IEvent) method.
void	register(IEventReceiver receiver, IEvent template, IEventMapper mapping, int priority, boolean async) See the general contract of the register(IEventReceiver, IEvent) method.
void	register(IEventReceiver receiver, IEvent template, int priority, boolean async) See the general contract of the register(IEventReceiver, IEvent) method.
void	register(IEventSender sender) Registers an event sender instance.
void	resume(IEventReceiver receiver) Resumes a previously suspended event receiver.
void	send(IEvent event, IEventSender sender) Sends the specified event to all receivers that have registered for this kind of event.
void	suspend(IEventReceiver receiver) Suspend the event receiver.
void	unregister(IEventReceiver receiver, IEvent template) Unregisters an event receiver/template tuple.
void	unregister(IEventSender sender) Unregisteres the event sender instance.

Field Detail

PRIO_MAX

public static final int PRIO_MAX

See Also:

Constant Field Values

PRIO_MIN

public static final int PRIO_MIN

See Also:

Constant Field Values

Method Detail

send

public void send(IEvent event,
                 IEventSender sender)
          throws WcmException

Sends the specified event to all receivers that have registered for this kind of event.

Parameters:

event - The event so send.

sender - The event sended instance (the caller).

Throws:

WcmException - If the event sender is not registered.

register

public void register(IEventSender sender)
              throws WcmException

Registers an event sender instance.

Parameters:

sender - The event sender.

Throws:

WcmException - Exception raised in failure situation

register

public void register(IEventReceiver receiver,
                     IEvent template)
              throws WcmException

Registers an event receiver. The receiver will only receive events which match the template event. This depends on the matching rules imlemented in the events IEvent.isLike(IEvent) method. Usually the event's instance and type are relevant.

It is allowed to register the same event receiver instance several times with different templates.

Parameters:

receiver - The event receiver to register

template - The event template

Throws:

WcmException

register

public void register(IEventReceiver receiver,
                     IEvent template,
                     IEventMapper mapping)
              throws WcmException

See the general contract of the register(IEventReceiver, IEvent) method. This regstration method has an additional IEventMapper argument.

Parameters:

receiver - The event receiver to register

template - The event template

mapping - The event mapper

Throws:

WcmException

See Also:

IEventMapper

register

public void register(IEventReceiver receiver,
                     IEvent template,
                     int priority,
                     boolean async)
              throws WcmException

See the general contract of the register(IEventReceiver, IEvent) method. This regstration method has two additional arguments for priority and asynchronous events.

The priority controls the order of multible receivers which have registered for the same event(s). Receivers with higher priority (smaller values) will receive an event before receivers with lower priority (greater values).

An event receiver can choose to receive events asynchronously. This means that a dedicated event queue and sender thread is created for each receiver and template. The event sender will not be blocked, that means the send() method puts the event into the queue and returns immediatelly.

Parameters:

receiver - The event receiver to register

template - The event template

priority - The priority of this receiver and template.

async - If true, the receiver will receive the events on a seperate thread.

Throws:

WcmException

register

public void register(IEventReceiver receiver,
                     IEvent template,
                     IEventMapper mapping,
                     int priority,
                     boolean async)
              throws WcmException

See the general contract of the register(IEventReceiver, IEvent) method.

Parameters:

receiver - The event receiver to register

template - The event template

mapping - The event mapper

priority - The priority of this receiver and template.

async - If true, the receiver will receive the events on a seperate thread.

Throws:

WcmException

See Also:

register(IEventReceiver, IEvent, IEventMapper), register(IEventReceiver, IEvent, int, boolean)

unregister

public void unregister(IEventSender sender)
                throws WcmException

Unregisteres the event sender instance.

Parameters:

sender - The event sender to unregister

Throws:

WcmException

unregister

public void unregister(IEventReceiver receiver,
                       IEvent template)
                throws WcmException

Unregisters an event receiver/template tuple.

Parameters:

receiver - The event receiver

template - The event template

Throws:

WcmException

suspend

public void suspend(IEventReceiver receiver)

Suspend the event receiver. The broker will stop delivering any events until resume(IEventReceiver) is called.

Parameters:

receiver - The receiver to suspend

resume

public void resume(IEventReceiver receiver)

Resumes a previously suspended event receiver. The broker will continue delivering events to the receiver.

Parameters:

receiver - The receiver to resume

hold

public void hold(IEventReceiver receiver,
                 boolean collect)

getMode

public SenderMode getMode(IEventReceiver receiver)

getHoldEvents

public IEventList getHoldEvents(IEventReceiver receiver)

clearHoldEvents

public IEventList clearHoldEvents(IEventReceiver receiver)

getEvents

public IEventList getEvents()