BEA Systems, Inc.

WebLogic Server 5.1.0 API Reference

weblogic.event.common
Interface EventTopicDef


public interface EventTopicDef

Representation of topics in the WebLogic Server Event Topic tree. Provides operations for creating subtopics, submitting event messages, and submitting registrations of interest in events.

Author:
Copyright (c) 1995-1998 by WebLogic, Inc. All Rights Reserved., Copyright (c) 1998-2000 BEA Systems, Inc. All Rights Reserved.
See Also:
EventServicesDef

Field Summary
static java.lang.String DELIM
          Sets the delimiter for representation of a topic's place in the hierarchy of the topic tree.
static int DURABLE
          Represents the lifetime of a topic to end when all of the pending events have been evaluated and there are no more registrations of interest for the topic.
static int EPHEMERAL
          Represents the lifetime of a topic to end when there are no more registrations of interest for the topic, even if there are pending events that have not yet been evaluated.
static int PERSISTENT
          Represents the lifetime of a topic to persistent even though there are no registrations of interest for the topic and there are no pending events to be evaluated.
 
Method Summary
 EventTopicDef getEventTopic(java.lang.String subTopic)
          Creates a subtopic in the topic tree.
 EventTopicDef getEventTopic(java.lang.String subTopic, int lifetime)
          Creates a subtopic with the specified lifetime.
 java.lang.String getName()
          Returns the string representation of a topic.
 int getRegistrationCount()
          Returns the number of registrations that are associated with this EventTopic.
 EventRegistrationDef register(Evaluate evaluate, Action action)
          Registers interest in an events corresponding to a topic.
 EventRegistrationDef register(Evaluate evaluate, Action action, boolean sink, boolean phase, int count)
          Registers interest in an events corresponding to a topic.
 java.lang.String submit(java.lang.Object body)
          Submits an EventMessage to the WebLogic Server for a topic.
 

Field Detail

EPHEMERAL

public static final int EPHEMERAL
Represents the lifetime of a topic to end when there are no more registrations of interest for the topic, even if there are pending events that have not yet been evaluated.

DURABLE

public static final int DURABLE
Represents the lifetime of a topic to end when all of the pending events have been evaluated and there are no more registrations of interest for the topic.

PERSISTENT

public static final int PERSISTENT
Represents the lifetime of a topic to persistent even though there are no registrations of interest for the topic and there are no pending events to be evaluated.

DELIM

public static final java.lang.String DELIM
Sets the delimiter for representation of a topic's place in the hierarchy of the topic tree.
Method Detail

getName

public java.lang.String getName()
Returns the string representation of a topic.

Returns:
Name of a topic

submit

public java.lang.String submit(java.lang.Object body)
                        throws EventGenerationException
Submits an EventMessage to the WebLogic Server for a topic.

Parameters:
body - Object to submitted as an EventMessage
Returns:
Confirmation string from the WebLogic Server
Throws:
EventGenerationException - if the event cannot be submitted

getEventTopic

public EventTopicDef getEventTopic(java.lang.String subTopic)
                            throws T3Exception
Creates a subtopic in the topic tree. The subTopic will be created relative to a topic, and may have intermediary nodes. For example, If a topic is "a.b.c", you may call getEventTopic("d.e.f"), and the topic "a.b.c.d.e.f" will be returned.

Parameters:
subTopic - String representing a subtopic
Returns:
subTopic
Throws:
T3Exception - if an invalid topic is supplied

getEventTopic

public EventTopicDef getEventTopic(java.lang.String subTopic,
                                   int lifetime)
                            throws T3Exception
Creates a subtopic with the specified lifetime. EventTopicDef.EPHEMERAL will cause the topic to disappear after the last deregistration. If EventTopicDef.DURABLE, the topic will remain in the tree when there are no registrations. EventTopicDef.PERSISTENT is not yet implemented.

Parameters:
subTopic - String representing a subTopic
lifetime - How long a topic will remain in the topic tree
Returns:
subTopic
Throws:
T3Exception - if an invalid topic is supplied

register

public EventRegistrationDef register(Evaluate evaluate,
                                     Action action)
                              throws EventRegistrationException
Registers interest in an events corresponding to a topic. Returns an EventRegistrationDef object which can be used to unregister interest.

Parameters:
evaluate - Evaluate object for the registration
action - Action object for the registration
Returns:
EventRegistrationDef
Throws:
EventRegistrationException - if the event registration cannot be created

register

public EventRegistrationDef register(Evaluate evaluate,
                                     Action action,
                                     boolean sink,
                                     boolean phase,
                                     int count)
                              throws EventRegistrationException
Registers interest in an events corresponding to a topic.

Parameters:
evaluate - An Evaluate object that implements weblogic.event.evaluators.EvaluateDef interface
action - An Action object that implements weblogic.event.actions.ActionDef interface
sink - true if the registration should receive notification of every event in which it has registered interest, as well as notification of events in any more specific topics
phase - true if this registration is interested in the "true" state of the evaluation
count - Specifies the number of events that this registration should receive before automatically unregistering itself; specify weblogic.event.common.EventRegistrationDef.UNCOUNTED for an unlimited registration
Returns:
EventRegistration
Throws:
EventRegistrationException - if the event registration cannot be created

getRegistrationCount

public int getRegistrationCount()
                         throws EventRegistrationException
Returns the number of registrations that are associated with this EventTopic. Does not include registrations above it in the topic tree that may also receive events delivered to this topic.

Returns:
Number of event registrations for topic
Throws:
EventRegistrationException - if an exception occurs during processing.

Documentation is available at
http://www.weblogic.com/docs51