TopicSessionpublic interface TopicSession implements SessionA TopicSession object provides methods for creating
TopicPublisher, TopicSubscriber, and
TemporaryTopic objects. It also provides a method for
deleting its client's durable subscribers.
A TopicSession is used for creating Pub/Sub specific
objects. In general, use the Session object, and
use TopicSession only to support
existing code. Using the Session object simplifies the
programming model, and allows transactions to be used across the two
messaging domains.
A TopicSession cannot be used to create objects specific to the
point-to-point domain. The following methods inherit from
Session, but must throw an
IllegalStateException
if used from TopicSession:
createBrowser
createQueue
createTemporaryQueue
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| Methods Summary |
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| public TopicSubscriber | createDurableSubscriber(Topic topic, java.lang.String name)Creates 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. The JMS provider
retains a record of this
durable subscription and insures that all messages from the topic's
publishers are retained until they are 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 that
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.
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.
| | public TopicSubscriber | createDurableSubscriber(Topic topic, java.lang.String name, java.lang.String messageSelector, boolean noLocal)Creates a durable subscriber to the specified topic, using a
message selector or specifying whether messages published by its
own connection should be delivered to it.
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. The JMS provider
retains a record of this
durable subscription and insures that all messages from the topic's
publishers are retained until they are 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.
| | public TopicPublisher | createPublisher(Topic topic)Creates a publisher for the specified topic.
A client uses a TopicPublisher object to publish
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.
| | public TopicSubscriber | createSubscriber(Topic topic)Creates a nondurable subscriber to the specified topic.
A client uses a TopicSubscriber object to receive
messages that have been published to a topic.
Regular TopicSubscriber objects are not durable.
They receive only 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.
| | public TopicSubscriber | createSubscriber(Topic topic, java.lang.String messageSelector, boolean noLocal)Creates a nondurable subscriber to the specified topic, using a
message selector or specifying whether messages published by its
own connection should be delivered to it.
A client uses a TopicSubscriber object to receive
messages that have been published to a topic.
Regular TopicSubscriber objects are not durable.
They receive only 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 do not 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.
The default value for this attribute is false.
| | public TemporaryTopic | createTemporaryTopic()Creates a TemporaryTopic object. Its lifetime will be that
of the TopicConnection unless it is deleted earlier.
| | public Topic | createTopic(java.lang.String topicName)Creates 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 administrative task and is not
to be initiated by the JMS API. The one exception is the
creation of temporary topics, which is accomplished with the
createTemporaryTopic method.
| | public void | unsubscribe(java.lang.String name)Unsubscribes a durable subscription that has been created by a client.
This method 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 there is an active TopicSubscriber for the
subscription, or while a consumed message is part of a pending
transaction or has not been acknowledged in the session.
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