cern::cmw::mom::pubsub::Subscriber Interface Reference

Inheritance diagram for cern::cmw::mom::pubsub::Subscriber:

[legend]List of all members.

Public Member Functions
void	setExceptionListener (ExceptionListener listener)
void	close ()
long	subscribe (String topic, SubscriptionListener listener, String selector) throws JMSException, NamingException
void	unSubscribe (long subscriptionToken) throws JMSException
void	unSubscribeAll () throws JMSException

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Detailed Description

Public interface. Provide topic subscription facilities.

Two kinds of exception are thrown :

• javax.jms.JMSException are thrown for exceptions caused by a problem in the underlying implementation.
• javax.naming.NamingException are thrown if the topic usage is not correct. Each time a topic is used, either in publication or in subscription, the topic name is checked against a topic namespace, to avoid namespace pollution and performance degradation.

This example shows a simple subscription to a topic:

<blockquote>

 try {
   s = PubSubFactory.subscriber();
 } catch (MOMException momEx) { ... }
 try {
   subToken = s.subscribe("CMW.DEVICES.PowerConverter.PC1.Current", listener, selector);
   // ...
   s.unSubscribe(subToken);
   s.close();
 }
 catch (JMSException jmsEx) { ... }
 catch (NamingException namingEx) { ... }
 </blockquote>

where listener is an instance of a class implementing the SubscriptionListener interface method void onMessage(Message m) and selector is an optional String defining a message selector.

See also:

Publisher

SubscriptionListener

PubSubFactory

NotificationHelper

cern.cmw.mom.mapping.MappingService

Version:

1.0 23 Jan 2001

Author:

Controls Middleware Project

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Member Function Documentation

void cern::cmw::mom::pubsub::Subscriber::close (   )

Close the publisher singleton instance and dealloacate any resource. Implemented in cern::cmw::mom::pubsub::impl::DefaultSubscriberImpl.

void cern::cmw::mom::pubsub::Subscriber::setExceptionListener (  ExceptionListener  listener  )

Set the listener for exceptions handling Parameters: listener  The exceptions listener

long cern::cmw::mom::pubsub::Subscriber::subscribe (  String  topic, SubscriptionListener  listener, String  selector )  throws JMSException, NamingException

Subscribe to the given topic. Parameters: topic  The String representation of the topic listener  An instance of a class implementing the SubscriptionListener interface selector  The String representation of the filter. May be null. Exceptions: JMSException  if JMS fails to subscribe due to some internal JMS error. NamingException  if there is a violation in the namespace policy. Returns: long the unique subscription token. Implemented in cern::cmw::mom::pubsub::impl::DefaultSubscriberImpl.

void cern::cmw::mom::pubsub::Subscriber::unSubscribe (  long  subscriptionToken  )  throws JMSException

Close the subscription identified by the subscriptionToken. Parameters: subscriptionToken  The subscription identifier Exceptions: JMSException  if JMS fails to unsubscribe due to some internal JMS error. Implemented in cern::cmw::mom::pubsub::impl::DefaultSubscriberImpl.

void cern::cmw::mom::pubsub::Subscriber::unSubscribeAll (   )  throws JMSException

Close all the opened subscriptions. Exceptions: JMSException  if JMS fails to unsubscribe due to some internal JMS error. Implemented in cern::cmw::mom::pubsub::impl::DefaultSubscriberImpl.

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The documentation for this interface was generated from the following file:

• Subscriber.java

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