public interface TopicSession extends Session
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
AUTO_ACKNOWLEDGE, CLIENT_ACKNOWLEDGE, DUPS_OK_ACKNOWLEDGE, SESSION_TRANSACTED| Modifier and Type | Method and Description |
|---|---|
TopicSubscriber |
createDurableSubscriber(Topic topic,
java.lang.String name)
Creates an unshared durable subscription on the specified topic (if one does not already exist) and creates a
consumer on that durable subscription.
|
TopicSubscriber |
createDurableSubscriber(Topic topic,
java.lang.String name,
java.lang.String messageSelector,
boolean noLocal)
Creates an unshared durable subscription on the specified topic (if one does not already exist), specifying a message
selector and the
noLocal parameter, and creates a consumer on that durable subscription. |
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,
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.
|
TemporaryTopic |
createTemporaryTopic()
Creates a
TemporaryTopic object. |
Topic |
createTopic(java.lang.String topicName)
Creates a topic identity given a
Topic name. |
void |
unsubscribe(java.lang.String name)
Unsubscribes a durable subscription that has been created by a client.
|
close, commit, createBrowser, createBrowser, createBytesMessage, createConsumer, createConsumer, createConsumer, createDurableConsumer, createDurableConsumer, createMapMessage, createMessage, createObjectMessage, createObjectMessage, createProducer, createQueue, createSharedConsumer, createSharedConsumer, createSharedDurableConsumer, createSharedDurableConsumer, createStreamMessage, createTemporaryQueue, createTextMessage, createTextMessage, getAcknowledgeMode, getMessageListener, getTransacted, recover, rollback, run, setMessageListenerTopic createTopic(java.lang.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 Jakarta Messaging API. The one exception is the creation of temporary topics, which is
accomplished with the createTemporaryTopic method.
createTopic in interface SessiontopicName - the name of this TopicTopic with the given nameJMSException - if the session fails to create a topic due to some internal error.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 toJMSException - if the session fails to create a subscriber due to some internal error.InvalidDestinationException - if an invalid topic is specified.TopicSubscriber createSubscriber(Topic topic, java.lang.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 connectionJMSException - 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.TopicSubscriber createDurableSubscriber(Topic topic, java.lang.String name) throws JMSException
noLocal value of false.
A durable subscription is used by an application which needs to receive all the messages published on a topic, including the ones published when there is no active consumer associated with it. The Jakarta Messaging provider retains a record of this durable subscription and ensures that all messages from the topic's publishers are retained until they are delivered to, and acknowledged by, a consumer on this durable subscription or until they have expired.
A durable subscription will continue to accumulate messages until it is deleted using the unsubscribe method.
This method may only be used with non-shared durable subscriptions. Any durable subscription created using this
method will be non-shared. This means that only one active (i.e. not closed) consumer on the subscription may exist
at a time. The term "consumer" here means a TopicSubscriber, MessageConsumer or JMSConsumer
object in any client.
An unshared durable subscription is identified by a name specified by the client and by the client identifier, which must be set. An application which subsequently wishes to create a consumer on that non-shared durable subscription must use the same client identifier.
If an unshared durable subscription already exists with the same name and client identifier and the same topic and
message selector, and there is no consumer already active (i.e. not closed) on the durable subscription, and no
consumed messages from that subscription are still part of a pending transaction or are not yet acknowledged in the
session, then this method creates a TopicSubscriber on the existing durable subscription.
If an unshared durable subscription already exists with the same name and client identifier, and there is a consumer
already active (i.e. not closed) on the durable subscription, or consumed messages from that subscription are still
part of a pending transaction or are not yet acknowledged in the session, then a JMSException will be thrown.
If an unshared durable subscription already exists with the same name and client identifier but a different topic,
message selector or noLocal value has been specified, and there is no consumer already active (i.e. not
closed) on the durable subscription, and no consumed messages from that subscription are still part of a pending
transaction or are not yet acknowledged in the session, then the durable subscription will be deleted and a new one
created.
A shared durable subscription and an unshared durable subscription may not have the same name and client identifier.
If a shared durable subscription already exists with the same name and client identifier then a JMSException
is thrown.
There is no restriction on durable subscriptions and shared non-durable subscriptions having the same name and clientId. Such subscriptions would be completely separate.
This method is identical to the corresponding createDurableConsumer method except that it returns a
TopicSubscriber rather than a MessageConsumer to represent the consumer.
createDurableSubscriber in interface Sessiontopic - the non-temporary Topic to subscribe toname - the name used to identify this subscriptionInvalidDestinationException - if an invalid topic is specified.JMSException - TopicSubscriber due to some
internal error
TopicSubscriber createDurableSubscriber(Topic topic, java.lang.String name, java.lang.String messageSelector, boolean noLocal) throws JMSException
noLocal parameter, and creates a consumer on that durable subscription.
A durable subscription is used by an application which needs to receive all the messages published on a topic, including the ones published when there is no active consumer associated with it. The Jakarta Messaging provider retains a record of this durable subscription and ensures that all messages from the topic's publishers are retained until they are delivered to, and acknowledged by, a consumer on this durable subscription or until they have expired.
A durable subscription will continue to accumulate messages until it is deleted using the unsubscribe method.
This method may only be used with non-shared durable subscriptions. Any durable subscription created using this
method will be non-shared. This means that only one active (i.e. not closed) consumer on the subscription may exist
at a time. The term "consumer" here means a TopicSubscriber, MessageConsumer or JMSConsumer
object in any client.
An unshared durable subscription is identified by a name specified by the client and by the client identifier, which must be set. An application which subsequently wishes to create a consumer on that non-shared durable subscription must use the same client identifier.
If an unshared durable subscription already exists with the same name and client identifier and the same topic and
message selector, and there is no consumer already active (i.e. not closed) on the durable subscription, and no
consumed messages from that subscription are still part of a pending transaction or are not yet acknowledged in the
session, then this method creates a TopicSubscriber on the existing durable subscription.
If an unshared durable subscription already exists with the same name and client identifier, and there is a consumer
already active (i.e. not closed) on the durable subscription, or consumed messages from that subscription are still
part of a pending transaction or are not yet acknowledged in the session, then a JMSException will be thrown.
If an unshared durable subscription already exists with the same name and client identifier but a different topic,
message selector or noLocal value has been specified, and there is no consumer already active (i.e. not
closed) on the durable subscription, and no consumed messages from that subscription are still part of a pending
transaction or are not yet acknowledged in the session, then the durable subscription will be deleted and a new one
created.
A shared durable subscription and an unshared durable subscription may not have the same name and client identifier.
If a shared durable subscription already exists with the same name and client identifier then a JMSException
is thrown.
If noLocal is set to true then any messages published to the topic using this session's connection, or any
other connection with the same client identifier, will not be added to the durable subscription.
There is no restriction on durable subscriptions and shared non-durable subscriptions having the same name and clientId. Such subscriptions would be completely separate.
This method is identical to the corresponding createDurableConsumer method except that it returns a
TopicSubscriber rather than a MessageConsumer to represent the consumer.
createDurableSubscriber in interface Sessiontopic - the non-temporary Topic to subscribe toname - the name used to identify this subscriptionmessageSelector - only messages with properties matching the message selector expression are added to the
durable subscription. A value of null or an empty string indicates that there is no message selector for the durable
subscription.noLocal - if true then any messages published to the topic using this session's connection, or any other
connection with the same client identifier, will not be added to the durable subscription.InvalidDestinationException - if an invalid topic is specified.InvalidSelectorException - if the message selector is invalid.JMSException - TopicSubscriber due to some
internal error
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 producerJMSException - if the session fails to create a publisher due to some internal error.InvalidDestinationException - if an invalid topic is specified.TemporaryTopic createTemporaryTopic() throws JMSException
TemporaryTopic object. Its lifetime will be that of the TopicConnection unless it is
deleted earlier.createTemporaryTopic in interface SessionJMSException - if the session fails to create a temporary topic due to some internal error.void unsubscribe(java.lang.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 Sessionname - the name used to identify this subscriptionJMSException - if the session fails to unsubscribe to the durable subscription due to some internal error.InvalidDestinationException - if an invalid subscription name is specified.