javax.jms
Interface TopicSession

public interface TopicSession

extends Session

A TopicSession provides methods for creating TopicPublisher's, TopicSubscriber's and TemporaryTopics. It also provides a method for deleting its client's durable subscribers.

See Also:

Session, TopicConnection.createTopicSession(boolean, int), XATopicSession.getTopicSession()

Fields inherited from interface javax.jms.Session

AUTO_ACKNOWLEDGE, CLIENT_ACKNOWLEDGE, DUPS_OK_ACKNOWLEDGE

Method Summary

TopicSubscriber	createDurableSubscriber(Topic topic, java.lang.String name) Create a durable Subscriber to the specified topic.
TopicSubscriber	createDurableSubscriber(Topic topic, java.lang.String name, java.lang.String messageSelector, boolean noLocal) Create a durable Subscriber to the specified topic.
TopicPublisher	createPublisher(Topic topic) Create a Publisher for the specified topic.
TopicSubscriber	createSubscriber(Topic topic) Create a non-durable Subscriber to the specified topic.
TopicSubscriber	createSubscriber(Topic topic, java.lang.String messageSelector, boolean noLocal) Create a non-durable Subscriber to the specified topic.
TemporaryTopic	createTemporaryTopic() Create a temporary topic.
Topic	createTopic(java.lang.String topicName) Create a topic identity given a Topic name.
void	unsubscribe(java.lang.String name) Unsubscribe a durable subscription that has been created by a client.

Methods inherited from interface javax.jms.Session

close, commit, createBytesMessage, createMapMessage, createMessage, createObjectMessage, createObjectMessage, createStreamMessage, createTextMessage, createTextMessage, getMessageListener, getTransacted, recover, rollback, run, setMessageListener

Method Detail

createTopic

public Topic createTopic(java.lang.String topicName)
                  throws JMSException

Create a topic identity given a Topic name.

This facility is provided for the rare cases where clients need to dynamically manipulate topic identity. This allows the creation of a topic identity with a provider specific name. Clients that depend on this ability are not portable.

Note that this method is not for creating the physical topic. The physical creation of topics is an administration task and not to be initiated by the JMS interface. The one exception is the creation of temporary topics is done using the createTemporaryTopic method.

Parameters:

topicName - the name of this topic

Returns:

a Topic with the given name.

Throws:

JMSException - if a session fails to create a topic due to some JMS error.

createSubscriber

public TopicSubscriber createSubscriber(Topic topic)
                                 throws JMSException

Create a non-durable Subscriber to the specified topic.

A client uses a TopicSubscriber for receiving messages that have been published to a topic.

Regular TopicSubscriber's are not durable. They only receive messages that are published while they are active.

In some cases, a connection may both publish and subscribe to a topic. The subscriber NoLocal attribute allows a subscriber to inhibit the delivery of messages published by its own connection. The default value for this attribute is false.

Parameters:

topic - the topic to subscribe to

Throws:

JMSException - if a session fails to create a subscriber due to some JMS error.

InvalidDestinationException - if invalid Topic specified.

createSubscriber

public TopicSubscriber createSubscriber(Topic topic,
                                        java.lang.String messageSelector,
                                        boolean noLocal)
                                 throws JMSException

Create a non-durable Subscriber to the specified topic.

A client uses a TopicSubscriber for receiving messages that have been published to a topic.

Regular TopicSubscriber's are not durable. They only receive messages that are published while they are active.

Messages filtered out by a subscriber's message selector will never be delivered to the subscriber. From the subscriber's perspective they simply don't exist.

In some cases, a connection may both publish and subscribe to a topic. The subscriber NoLocal attribute allows a subscriber to inhibit the delivery of messages published by its own connection.

Parameters:

topic - the topic to subscribe to

messageSelector - only messages with properties matching the message selector expression are delivered. This value may be null.

noLocal - if set, inhibits the delivery of messages published by its own connection.

Throws:

JMSException - if a session fails to create a subscriber due to some JMS error or invalid selector.

InvalidDestinationException - if invalid Topic specified.

InvalidSelectorException - if the message selector is invalid.

createDurableSubscriber

public TopicSubscriber createDurableSubscriber(Topic topic,
                                               java.lang.String name)
                                        throws JMSException

Create a durable Subscriber to the specified topic.

If a client needs to receive all the messages published on a topic including the ones published while the subscriber is inactive, it uses a durable TopicSubscriber. JMS retains a record of this durable subscription and insures that all messages from the topic's publishers are retained until they are either acknowledged by this durable subscriber or they have expired.

Sessions with durable subscribers must always provide the same client identifier. In addition, each client must specify a name which uniquely identifies (within client identifier) each durable subscription it creates. Only one session at a time can have a TopicSubscriber for a particular durable subscription.

A client can change an existing durable subscription by creating a durable TopicSubscriber with the same name and a new topic and/or message selector. Changing a durable subscriber is equivalent to unsubscribing(deleting) the old one and creating a new one.

Parameters:

topic - the non-temporary topic to subscribe to

name - the name used to identify this subscription.

Throws:

JMSException - if a session fails to create a subscriber due to some JMS error.

InvalidDestinationException - if invalid Topic specified.

createDurableSubscriber

public TopicSubscriber createDurableSubscriber(Topic topic,
                                               java.lang.String name,
                                               java.lang.String messageSelector,
                                               boolean noLocal)
                                        throws JMSException

Create a durable Subscriber to the specified topic.

If a client needs to receive all the messages published on a topic including the ones published while the subscriber is inactive, it uses a durable TopicSubscriber. JMS retains a record of this durable subscription and insures that all messages from the topic's publishers are retained until they are either acknowledged by this durable subscriber or they have expired.

Sessions with durable subscribers must always provide the same client identifier. In addition, each client must specify a name which uniquely identifies (within client identifier) each durable subscription it creates. Only one session at a time can have a TopicSubscriber for a particular durable subscription. An inactive durable subscriber is one that exists but does not currently have a message consumer associated with it.

A client can change an existing durable subscription by creating a durable TopicSubscriber with the same name and a new topic and/or message selector. Changing a durable subscriber is equivalent to unsubscribing(deleting) the old one and creating a new one.

Parameters:

topic - the non-temporary topic to subscribe to

name - the name used to identify this subscription.

messageSelector - only messages with properties matching the message selector expression are delivered. This value may be null.

noLocal - if set, inhibits the delivery of messages published by its own connection.

Throws:

JMSException - if a session fails to create a subscriber due to some JMS error or invalid selector.

InvalidDestinationException - if invalid Topic specified.

InvalidSelectorException - if the message selector is invalid.

createPublisher

public TopicPublisher createPublisher(Topic topic)
                               throws JMSException

Create a Publisher for the specified topic.

A client uses a TopicPublisher for publishing messages on a topic. Each time a client creates a TopicPublisher on a topic, it defines a new sequence of messages that have no ordering relationship with the messages it has previously sent.

Parameters:

topic - the topic to publish to, or null if this is an unidentifed producer.

Throws:

JMSException - if a session fails to create a publisher due to some JMS error.

InvalidDestinationException - if invalid Topic specified.

createTemporaryTopic

public TemporaryTopic createTemporaryTopic()
                                    throws JMSException

Create a temporary topic. It's lifetime will be that of the TopicConnection unless deleted earlier.

Returns:

a temporary topic identity

Throws:

JMSException - if a session fails to create a temporary topic due to some JMS error.

unsubscribe

public void unsubscribe(java.lang.String name)
                 throws JMSException

Unsubscribe a durable subscription that has been created by a client.

This deletes the state being maintained on behalf of the subscriber by its provider.

It is erroneous for a client to delete a durable subscription while it has an active TopicSubscriber for it, or while a message received by it is part of a transaction or has not been acknowledged in the session.

Parameters:

name - the name used to identify this subscription.

Throws:

JMSException - if JMS fails to unsubscribe to durable subscription due to some JMS error.

InvalidDestinationException - if an invalid subscription name is specified.