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JavaTM 2 Platform Ent. Ed. v1.4 |
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A 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
Session
,
Connection.createSession(boolean, int)
,
TopicConnection.createTopicSession(boolean, int)
,
XATopicSession.getTopicSession()
Field Summary |
Fields inherited from interface javax.jms.Session |
AUTO_ACKNOWLEDGE, CLIENT_ACKNOWLEDGE, DUPS_OK_ACKNOWLEDGE, SESSION_TRANSACTED |
Method Summary | |
TopicSubscriber |
createDurableSubscriber(Topic topic,
String name)
Creates a durable subscriber to the specified topic. |
TopicSubscriber |
createDurableSubscriber(Topic topic,
String name,
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. |
TopicPublisher |
createPublisher(Topic topic)
Creates a publisher for the specified topic. |
TopicSubscriber |
createSubscriber(Topic topic)
Creates a nondurable subscriber to the specified topic. |
TopicSubscriber |
createSubscriber(Topic topic,
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. |
TemporaryTopic |
createTemporaryTopic()
Creates a TemporaryTopic object. |
Topic |
createTopic(String topicName)
Creates a topic identity given a Topic name.
|
void |
unsubscribe(String name)
Unsubscribes a durable subscription that has been created by a client. |
Methods inherited from interface javax.jms.Session |
close, commit, createBrowser, createBrowser, createBytesMessage, createConsumer, createConsumer, createConsumer, createMapMessage, createMessage, createObjectMessage, createObjectMessage, createProducer, createQueue, createStreamMessage, createTemporaryQueue, createTextMessage, createTextMessage, getAcknowledgeMode, getMessageListener, getTransacted, recover, rollback, run, setMessageListener |
Method Detail |
public Topic createTopic(String topicName) throws JMSException
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.
createTopic
in interface Session
topicName
- the name of this Topic
Topic
with the given name
JMSException
- if the session fails to create a topic
due to some internal error.public TopicSubscriber createSubscriber(Topic topic) throws JMSException
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.
topic
- the Topic
to subscribe to
JMSException
- if the session fails to create a subscriber
due to some internal error.
InvalidDestinationException
- if an invalid topic is specified.public TopicSubscriber createSubscriber(Topic topic, String messageSelector, boolean noLocal) throws JMSException
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.
topic
- the Topic
to subscribe tomessageSelector
- only messages with properties matching the
message selector expression are delivered. A value of null or
an empty string indicates that there is no message selector
for the message consumer.noLocal
- if set, inhibits the delivery of messages published
by its own connection
JMSException
- if the session fails to create a subscriber
due to some internal error.
InvalidDestinationException
- if an invalid topic is specified.
InvalidSelectorException
- if the message selector is invalid.public TopicSubscriber createDurableSubscriber(Topic topic, String name) throws JMSException
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.
createDurableSubscriber
in interface Session
topic
- the non-temporary Topic
to subscribe toname
- the name used to identify this subscription
JMSException
- if the session fails to create a subscriber
due to some internal error.
InvalidDestinationException
- if an invalid topic is specified.public TopicSubscriber createDurableSubscriber(Topic topic, String name, String messageSelector, boolean noLocal) throws JMSException
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.
createDurableSubscriber
in interface Session
topic
- the non-temporary Topic
to subscribe toname
- the name used to identify this subscriptionmessageSelector
- only messages with properties matching the
message selector expression are delivered. A value of null or
an empty string indicates that there is no message selector
for the message consumer.noLocal
- if set, inhibits the delivery of messages published
by its own connection
JMSException
- if the session fails to create a subscriber
due to some internal error.
InvalidDestinationException
- if an invalid topic is specified.
InvalidSelectorException
- if the message selector is invalid.public TopicPublisher createPublisher(Topic topic) throws JMSException
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.
topic
- the Topic
to publish to, or null if this is an
unidentified producer
JMSException
- if the session fails to create a publisher
due to some internal error.
InvalidDestinationException
- if an invalid topic is specified.public TemporaryTopic createTemporaryTopic() throws JMSException
TemporaryTopic
object. Its lifetime will be that
of the TopicConnection
unless it is deleted earlier.
createTemporaryTopic
in interface Session
JMSException
- if the session fails to create a temporary
topic due to some internal error.public void unsubscribe(String name) throws JMSException
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.
unsubscribe
in interface Session
name
- the name used to identify this subscription
JMSException
- if the session fails to unsubscribe to the
durable subscription due to some internal error.
InvalidDestinationException
- if an invalid subscription name
is specified.
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JavaTM 2 Platform Ent. Ed. v1.4 |
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Copyright 2003 Sun Microsystems, Inc. All rights reserved.