public interface Session
extends java.lang.Runnable, java.lang.AutoCloseable
A Session
object is a single-threaded context for producing and consuming
messages. Although it may allocate provider resources outside the Java
virtual machine (JVM), it is considered a lightweight JMS object.
A session serves several purposes:
TemporaryTopics
and
TemporaryQueues
.
Queue
or Topic
objects for those clients that need to dynamically manipulate
provider-specific destination names.
QueueBrowsers
.
A session can create and service multiple message producers and consumers.
One typical use is to have a thread block on a synchronous
MessageConsumer
until a message arrives. The thread may then
use one or more of the Session
's MessageProducer
s.
If a client desires to have one thread produce messages while others consume them, the client should use a separate session for its producing thread.
Once a connection has been started, any session with one or more
registered message listeners is dedicated to the thread of control that
delivers messages to it. It is erroneous for client code to use this session
or any of its constituent objects from another thread of control. The
only exception to this rule is the use of the session or connection
close
method.
It should be easy for most clients to partition their work naturally into sessions. This model allows clients to start simply and incrementally add message processing complexity as their need for concurrency grows.
The close
method is the only session method that can be
called while some other session method is being executed in another thread.
A session may be specified as transacted. Each transacted session supports a single series of transactions. Each transaction groups a set of message sends and a set of message receives into an atomic unit of work. In effect, transactions organize a session's input message stream and output message stream into series of atomic units. When a transaction commits, its atomic unit of input is acknowledged and its associated atomic unit of output is sent. If a transaction rollback is done, the transaction's sent messages are destroyed and the session's input is automatically recovered.
The content of a transaction's input and output units is simply those messages that have been produced and consumed within the session's current transaction.
A transaction is completed using either its session's commit
method or its session's rollback
method. The completion of a
session's current transaction automatically begins the next. The result is
that a transacted session always has a current transaction within which its
work is done.
The Java Transaction Service (JTS) or some other transaction monitor may
be used to combine a session's transaction with transactions on other
resources (databases, other JMS sessions, etc.). Since Java distributed
transactions are controlled via the Java Transaction API (JTA), use of the
session's commit
and rollback
methods in
this context is prohibited.
The JMS API does not require support for JTA; however, it does define how a provider supplies this support.
Although it is also possible for a JMS client to handle distributed transactions directly, it is unlikely that many JMS clients will do this. Support for JTA in the JMS API is targeted at systems vendors who will be integrating the JMS API into their application server products.
QueueSession
,
TopicSession
,
XASession
Modifier and Type | Field and Description |
---|---|
static int |
AUTO_ACKNOWLEDGE
With this acknowledgment mode, the session automatically acknowledges
a client's receipt of a message either when the session has successfully
returned from a call to
receive or when the message
listener the session has called to process the message successfully
returns. |
static int |
CLIENT_ACKNOWLEDGE
With this acknowledgment mode, the client acknowledges a consumed
message by calling the message's
acknowledge method. |
static int |
DUPS_OK_ACKNOWLEDGE
This acknowledgment mode instructs the session to lazily acknowledge
the delivery of messages.
|
static int |
SESSION_TRANSACTED
This value may be passed as the argument to the
method
createSession(int sessionMode)
on the Connection object
to specify that the session should use a local transaction. |
Modifier and Type | Method and Description |
---|---|
void |
close()
Closes the session.
|
void |
commit()
Commits all messages done in this transaction and releases any locks
currently held.
|
QueueBrowser |
createBrowser(Queue queue)
Creates a
QueueBrowser object to peek at the messages on
the specified queue. |
QueueBrowser |
createBrowser(Queue queue,
java.lang.String messageSelector)
Creates a
QueueBrowser object to peek at the messages on the
specified queue using a message selector. |
BytesMessage |
createBytesMessage()
Creates a
BytesMessage object. |
MessageConsumer |
createConsumer(Destination destination)
Creates a
MessageConsumer for the specified destination. |
MessageConsumer |
createConsumer(Destination destination,
java.lang.String messageSelector)
Creates a
MessageConsumer for the specified destination,
using a message selector. |
MessageConsumer |
createConsumer(Destination destination,
java.lang.String messageSelector,
boolean noLocal)
Creates a
MessageConsumer for the specified destination, specifying a
message selector and the noLocal parameter. |
MessageConsumer |
createDurableConsumer(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.
|
MessageConsumer |
createDurableConsumer(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. |
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. |
MapMessage |
createMapMessage()
Creates a
MapMessage object. |
Message |
createMessage()
Creates a
Message object. |
ObjectMessage |
createObjectMessage()
Creates an
ObjectMessage object. |
ObjectMessage |
createObjectMessage(java.io.Serializable object)
Creates an initialized
ObjectMessage object. |
MessageProducer |
createProducer(Destination destination)
Creates a
MessageProducer to send messages to the specified
destination. |
Queue |
createQueue(java.lang.String queueName)
Creates a
Queue object which encapsulates a specified
provider-specific queue name. |
MessageConsumer |
createSharedConsumer(Topic topic,
java.lang.String sharedSubscriptionName)
Creates a shared non-durable subscription with the specified name on the
specified topic (if one does not already exist) and creates a consumer on
that subscription.
|
MessageConsumer |
createSharedConsumer(Topic topic,
java.lang.String sharedSubscriptionName,
java.lang.String messageSelector)
Creates a shared non-durable subscription with the specified name on the
specified topic (if one does not already exist) specifying a message selector,
and creates a consumer on that subscription.
|
MessageConsumer |
createSharedDurableConsumer(Topic topic,
java.lang.String name)
Creates a shared 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. |
MessageConsumer |
createSharedDurableConsumer(Topic topic,
java.lang.String name,
java.lang.String messageSelector)
Creates a shared durable subscription on the specified topic (if one
does not already exist), specifying a message selector,
and creates a consumer on that durable subscription.
|
StreamMessage |
createStreamMessage()
Creates a
StreamMessage object. |
TemporaryQueue |
createTemporaryQueue()
Creates a
TemporaryQueue object. |
TemporaryTopic |
createTemporaryTopic()
Creates a
TemporaryTopic object. |
TextMessage |
createTextMessage()
Creates a
TextMessage object. |
TextMessage |
createTextMessage(java.lang.String text)
Creates an initialized
TextMessage object. |
Topic |
createTopic(java.lang.String topicName)
Creates a
Topic object which encapsulates a specified
provider-specific topic name. |
int |
getAcknowledgeMode()
Returns the acknowledgement mode of the session.
|
MessageListener |
getMessageListener()
Returns the session's distinguished message listener (optional).
|
boolean |
getTransacted()
Indicates whether the session is in transacted mode.
|
void |
recover()
Stops message delivery in this session, and restarts message delivery
with the oldest unacknowledged message.
|
void |
rollback()
Rolls back any messages done in this transaction and releases any locks
currently held.
|
void |
run()
Optional operation, intended to be used only by Application Servers,
not by ordinary JMS clients.
|
void |
setMessageListener(MessageListener listener)
Sets the session's distinguished message listener (optional).
|
void |
unsubscribe(java.lang.String name)
Unsubscribes a durable subscription that has been created by a client.
|
static final int AUTO_ACKNOWLEDGE
receive
or when the message
listener the session has called to process the message successfully
returns.static final int CLIENT_ACKNOWLEDGE
acknowledge
method.
Acknowledging a consumed message acknowledges all messages that the
session has consumed.
When client acknowledgment mode is used, a client may build up a large number of unacknowledged messages while attempting to process them. A JMS provider should provide administrators with a way to limit client overrun so that clients are not driven to resource exhaustion and ensuing failure when some resource they are using is temporarily blocked.
Message.acknowledge()
,
Constant Field Valuesstatic final int DUPS_OK_ACKNOWLEDGE
static final int SESSION_TRANSACTED
createSession(int sessionMode)
on the Connection
object
to specify that the session should use a local transaction.
This value is returned from the method
getAcknowledgeMode
if the session is using a local transaction,
irrespective of whether the session was created by calling the
method createSession(int sessionMode)
or the
method createSession(boolean transacted, int acknowledgeMode)
.
BytesMessage createBytesMessage() throws JMSException
BytesMessage
object. A BytesMessage
object is used to send a message containing a stream of uninterpreted
bytes.
The message object returned may be sent using any Session
or JMSContext
.
It is not restricted to being sent using the JMSContext
used to create it.
The message object returned may be optimised for use with the JMS provider used to create it. However it can be sent using any JMS provider, not just the JMS provider used to create it.
JMSException
- if the JMS provider fails to create this message
due to some internal error.MapMessage createMapMessage() throws JMSException
MapMessage
object. A MapMessage
object is used to send a self-defining set of name-value pairs, where
names are String
objects and values are primitive values
in the Java programming language.
The message object returned may be sent using any Session
or JMSContext
.
It is not restricted to being sent using the JMSContext
used to create it.
The message object returned may be optimised for use with the JMS provider used to create it. However it can be sent using any JMS provider, not just the JMS provider used to create it.
JMSException
- if the JMS provider fails to create this message
due to some internal error.Message createMessage() throws JMSException
Message
object. The Message
interface is the root interface of all JMS messages. A
Message
object holds all the
standard message header information. It can be sent when a message
containing only header information is sufficient.
The message object returned may be sent using any Session
or JMSContext
.
It is not restricted to being sent using the JMSContext
used to create it.
The message object returned may be optimised for use with the JMS provider used to create it. However it can be sent using any JMS provider, not just the JMS provider used to create it.
JMSException
- if the JMS provider fails to create this message
due to some internal error.ObjectMessage createObjectMessage() throws JMSException
ObjectMessage
object. An
ObjectMessage
object is used to send a message
that contains a serializable Java object.
The message object returned may be sent using any Session
or JMSContext
.
It is not restricted to being sent using the JMSContext
used to create it.
The message object returned may be optimised for use with the JMS provider used to create it. However it can be sent using any JMS provider, not just the JMS provider used to create it.
JMSException
- if the JMS provider fails to create this message
due to some internal error.ObjectMessage createObjectMessage(java.io.Serializable object) throws JMSException
ObjectMessage
object. An
ObjectMessage
object is used
to send a message that contains a serializable Java object.
The message object returned may be sent using any Session
or JMSContext
.
It is not restricted to being sent using the JMSContext
used to create it.
The message object returned may be optimised for use with the JMS provider used to create it. However it can be sent using any JMS provider, not just the JMS provider used to create it.
object
- the object to use to initialize this messageJMSException
- if the JMS provider fails to create this message
due to some internal error.StreamMessage createStreamMessage() throws JMSException
StreamMessage
object. A
StreamMessage
object is used to send a
self-defining stream of primitive values in the Java programming
language.
The message object returned may be sent using any Session
or JMSContext
.
It is not restricted to being sent using the JMSContext
used to create it.
The message object returned may be optimised for use with the JMS provider used to create it. However it can be sent using any JMS provider, not just the JMS provider used to create it.
JMSException
- if the JMS provider fails to create this message
due to some internal error.TextMessage createTextMessage() throws JMSException
TextMessage
object. A TextMessage
object is used to send a message containing a String
object.
The message object returned may be sent using any Session
or JMSContext
.
It is not restricted to being sent using the JMSContext
used to create it.
The message object returned may be optimised for use with the JMS provider used to create it. However it can be sent using any JMS provider, not just the JMS provider used to create it.
JMSException
- if the JMS provider fails to create this message
due to some internal error.TextMessage createTextMessage(java.lang.String text) throws JMSException
TextMessage
object. A
TextMessage
object is used to send
a message containing a String
.
The message object returned may be sent using any Session
or JMSContext
.
It is not restricted to being sent using the JMSContext
used to create it.
The message object returned may be optimised for use with the JMS provider used to create it. However it can be sent using any JMS provider, not just the JMS provider used to create it.
text
- the string used to initialize this messageJMSException
- if the JMS provider fails to create this message
due to some internal error.boolean getTransacted() throws JMSException
JMSException
- if the JMS provider fails to return the
transaction mode due to some internal error.int getAcknowledgeMode() throws JMSException
JMSException
- if the JMS provider fails to return the
acknowledgment mode due to some internal error.Connection.createSession(boolean, int)
void commit() throws JMSException
This method must not return until any incomplete asynchronous send operations for this Session have been completed and any CompletionListener callbacks have returned. Incomplete sends should be allowed to complete normally unless an error occurs.
A CompletionListener callback method must not call commit on its own Session. Doing so will cause an IllegalStateException to be thrown.
IllegalStateException
- JMSException
- if the JMS provider fails to commit the transaction due to
some internal error.TransactionRolledBackException
- if the transaction is rolled back due to some internal
error during commit.void rollback() throws JMSException
This method must not return until any incomplete asynchronous send operations for this Session have been completed and any CompletionListener callbacks have returned. Incomplete sends should be allowed to complete normally unless an error occurs.
A CompletionListener callback method must not call commit on its own Session. Doing so will cause an IllegalStateException to be thrown.
IllegalStateException
- JMSException
- if the JMS provider fails to roll back the
transaction due to some internal error.void close() throws JMSException
Since a provider may allocate some resources on behalf of a session outside the JVM, clients should close the resources when they are not needed. Relying on garbage collection to eventually reclaim these resources may not be timely enough.
There is no need to close the producers and consumers of a closed session.
This call will block until a receive
call or message
listener in progress has completed. A blocked message consumer
receive
call returns null
when this session is
closed.
This method must not return until any incomplete asynchronous send operations for this Session have been completed and any CompletionListener callbacks have returned. Incomplete sends should be allowed to complete normally unless an error occurs.
For the avoidance of doubt, if an exception listener for this session's
connection is running when close
is invoked, there is no
requirement for the close
call to wait until the exception
listener has returned before it may return.
Closing a transacted session must roll back the transaction in progress.
This method is the only Session
method that can be called
concurrently.
A MessageListener must not attempt to close its own Session as this would lead to deadlock. The JMS provider must detect this and throw a IllegalStateException.
A CompletionListener callback method must not call close on its own Session. Doing so will cause an IllegalStateException to be thrown.
Invoking any other Session
method on a closed session must
throw a IllegalStateException
. Closing a closed
session must not throw an exception.
close
in interface java.lang.AutoCloseable
IllegalStateException
- JMSException
- if the JMS provider fails to close the session due to some
internal error.void recover() throws JMSException
All consumers deliver messages in a serial order. Acknowledging a received message automatically acknowledges all messages that have been delivered to the client.
Restarting a session causes it to take the following actions:
JMSException
- if the JMS provider fails to stop and restart
message delivery due to some internal error.IllegalStateException
- if the method is called by a
transacted session.MessageListener getMessageListener() throws JMSException
This method must not be used in a Java EE web or EJB application.
Doing so may cause a JMSException
to be thrown though this is not guaranteed.
JMSException
- if the JMS provider fails to get the session's distinguished message
listener for one of the following reasons:
setMessageListener(javax.jms.MessageListener)
,
ServerSessionPool
,
ServerSession
void setMessageListener(MessageListener listener) throws JMSException
When the distinguished message listener is set, no other form of message receipt in the session can be used; however, all forms of sending messages are still supported.
This is an expert facility not used by ordinary JMS clients.
This method must not be used in a Java EE web or EJB application.
Doing so may cause a JMSException
to be thrown though this is not guaranteed.
listener
- the message listener to associate with this sessionJMSException
- if the JMS provider fails to set the session's distinguished message
listener for one of the following reasons:
getMessageListener()
,
ServerSessionPool
,
ServerSession
void run()
This method must not be used in a Java EE web or EJB application.
Doing so may cause a JMSRuntimeException
to be thrown though this is not guaranteed.
run
in interface java.lang.Runnable
JMSRuntimeException
- if this method has been called in a Java EE web or EJB application
(though it is not guaranteed that an exception is thrown in this case)ServerSession
MessageProducer createProducer(Destination destination) throws JMSException
MessageProducer
to send messages to the specified
destination.
A client uses a MessageProducer
object to send
messages to a destination. Since Queue
and Topic
both inherit from Destination
, they can be used in
the destination parameter to create a MessageProducer
object.
destination
- the Destination
to send to,
or null if this is a producer which does not have a specified
destination.JMSException
- if the session fails to create a MessageProducer
due to some internal error.InvalidDestinationException
- if an invalid destination
is specified.MessageConsumer createConsumer(Destination destination) throws JMSException
MessageConsumer
for the specified destination.
Since Queue
and Topic
both inherit from Destination
, they can be used in
the destination parameter to create a MessageConsumer
.destination
- the Destination
to access.JMSException
- if the session fails to create a consumer
due to some internal error.InvalidDestinationException
- if an invalid destination
is specified.MessageConsumer createConsumer(Destination destination, java.lang.String messageSelector) throws JMSException
MessageConsumer
for the specified destination,
using a message selector.
Since Queue
and Topic
both inherit from Destination
, they can be used in
the destination parameter to create a MessageConsumer
.
A client uses a MessageConsumer
object to receive
messages that have been sent to a destination.
destination
- the Destination
to accessmessageSelector
- 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.JMSException
- if the session fails to create a MessageConsumer
due to some internal error.InvalidDestinationException
- if an invalid destination
is specified.InvalidSelectorException
- if the message selector is invalid.MessageConsumer createConsumer(Destination destination, java.lang.String messageSelector, boolean noLocal) throws JMSException
MessageConsumer
for the specified destination, specifying a
message selector and the noLocal
parameter.
Since Queue
and Topic
both inherit from Destination
, they can be used in
the destination parameter to create a MessageConsumer
.
A client uses a MessageConsumer
object to receive
messages that have been published to a destination.
The noLocal
argument is for use when the
destination is a topic and the session's connection
is also being used to publish messages to that topic.
If noLocal
is set to true then the
MessageConsumer
will not receive messages published
to the topic by its own connection. The default value of this
argument is false. If the destination is a queue
then the effect of setting noLocal
to true is not specified.
destination
- the Destination
to accessmessageSelector
- 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 true, and the destination is a topic,
then the MessageConsumer
will
not receive messages published to the topic
by its own connection.JMSException
- if the session fails to create a MessageConsumer
due to some internal error.InvalidDestinationException
- if an invalid destination
is specified.InvalidSelectorException
- if the message selector is invalid.MessageConsumer createSharedConsumer(Topic topic, java.lang.String sharedSubscriptionName) throws JMSException
If a shared non-durable subscription already exists with the same name
and client identifier (if set), and the same topic and message selector
value has been specified, then this method creates a
MessageConsumer
on the existing subscription.
A non-durable shared subscription is used by a client which needs to be
able to share the work of receiving messages from a topic subscription
amongst multiple consumers. A non-durable shared subscription may
therefore have more than one consumer. Each message from the subscription
will be delivered to only one of the consumers on that subscription. Such
a subscription is not persisted and will be deleted (together with any
undelivered messages associated with it) when there are no consumers on
it. The term "consumer" here means a MessageConsumer
or
JMSConsumer
object in any client.
A shared non-durable subscription is identified by a name specified by the client and by the client identifier (which may be unset). An application which subsequently wishes to create a consumer on that shared non-durable subscription must use the same client identifier.
If a shared non-durable subscription already exists with the same name
and client identifier (if set) but a different topic or message selector
has been specified, and there is a consumer already
active (i.e. not closed) on the subscription, then a JMSException
will be thrown.
There is no restriction on durable subscriptions and shared non-durable subscriptions having the same name and clientId (which may be unset). Such subscriptions would be completely separate.
topic
- the Topic
to subscribe tosharedSubscriptionName
- the name used to identify the shared non-durable subscriptionJMSException
- if the session fails to create the shared non-durable
subscription and MessageConsumer
due to some internal
error.InvalidDestinationException
- if an invalid topic is specified.InvalidSelectorException
- if the message selector is invalid.MessageConsumer createSharedConsumer(Topic topic, java.lang.String sharedSubscriptionName, java.lang.String messageSelector) throws JMSException
If a shared non-durable subscription already exists with the same name
and client identifier (if set), and the same topic and message selector
has been specified, then this method creates a
MessageConsumer
on the existing subscription.
A non-durable shared subscription is used by a client which needs to be
able to share the work of receiving messages from a topic subscription
amongst multiple consumers. A non-durable shared subscription may
therefore have more than one consumer. Each message from the subscription
will be delivered to only one of the consumers on that subscription. Such
a subscription is not persisted and will be deleted (together with any
undelivered messages associated with it) when there are no consumers on
it. The term "consumer" here means a MessageConsumer
or
JMSConsumer
object in any client.
A shared non-durable subscription is identified by a name specified by the client and by the client identifier (which may be unset). An application which subsequently wishes to create a consumer on that shared non-durable subscription must use the same client identifier.
If a shared non-durable subscription already exists with the same name
and client identifier (if set) but a different topic or message selector
has been specified, and there is a consumer already
active (i.e. not closed) on the subscription, then a JMSException
will be thrown.
There is no restriction on durable subscriptions and shared non-durable subscriptions having the same name and clientId (which may be unset). Such subscriptions would be completely separate.
topic
- the Topic
to subscribe tosharedSubscriptionName
- the name used to identify the shared non-durable subscriptionmessageSelector
- only messages with properties matching the message selector
expression are added to the shared non-durable subscription. A
value of null or an empty string indicates that there is no
message selector for the shared non-durable subscription.JMSException
- if the session fails to create the shared non-durable
subscription and MessageConsumer
due to some
internal error.InvalidDestinationException
- if an invalid topic is specified.InvalidSelectorException
- if the message selector is invalid.Queue createQueue(java.lang.String queueName) throws JMSException
Queue
object which encapsulates a specified
provider-specific queue name.
The use of provider-specific queue names in an application may render the
application non-portable. Portable applications are recommended to not
use this method but instead look up an administratively-defined
Queue
object using JNDI.
Note that this method simply creates an object that encapsulates the name
of a queue. It does not create the physical queue in the JMS provider.
JMS does not provide a method to create the physical queue, since this
would be specific to a given JMS provider. Creating a physical queue is
provider-specific and is typically an administrative task performed by an
administrator, though some providers may create them automatically when
needed. The one exception to this is the creation of a temporary queue,
which is done using the createTemporaryQueue
method.
queueName
- A provider-specific queue nameJMSException
- if a Queue object cannot be created due to some internal errorTopic createTopic(java.lang.String topicName) throws JMSException
Topic
object which encapsulates a specified
provider-specific topic name.
The use of provider-specific topic names in an application may render the
application non-portable. Portable applications are recommended to not
use this method but instead look up an administratively-defined
Topic
object using JNDI.
Note that this method simply creates an object that encapsulates the name
of a topic. It does not create the physical topic in the JMS provider.
JMS does not provide a method to create the physical topic, since this
would be specific to a given JMS provider. Creating a physical topic is
provider-specific and is typically an administrative task performed by an
administrator, though some providers may create them automatically when
needed. The one exception to this is the creation of a temporary topic,
which is done using the createTemporaryTopic
method.
topicName
- A provider-specific topic nameJMSException
- if a Topic object cannot be created due to some internal
errorTopicSubscriber 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 JMS 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 unshared durable subscriptions. Any
durable subscription created using this method will be unshared. 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 unshared 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, message selector and
noLocal
value has been specified, and there is no consumer
already active (i.e. not closed) on the durable subscription 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, 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 then this is
equivalent to unsubscribing (deleting) the old one and creating a new
one.
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.
topic
- the non-temporary Topic
to subscribe toname
- the name used to identify this subscriptionInvalidDestinationException
- if an invalid topic is specified.IllegalStateException
- if the client identifier is unsetJMSException
- 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 JMS 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 unshared durable subscriptions. Any
durable subscription created using this method will be unshared. 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 unshared 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, message selector and
noLocal
value has been specified, and there is no consumer
already active (i.e. not closed) on the durable subscription 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, 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 then this is
equivalent to unsubscribing (deleting) the old one and creating a new
one.
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.
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.
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 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.IllegalStateException
- if the client identifier is unsetJMSException
- TopicSubscriber
due to some
internal error
MessageConsumer createDurableConsumer(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 JMS 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 unshared durable subscriptions. Any
durable subscription created using this method will be unshared. 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 unshared 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, message selector and
noLocal
value has been specified, and there is no consumer
already active (i.e. not closed) on the durable subscription then
this method creates a MessageConsumer
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, 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 then this is
equivalent to unsubscribing (deleting) the old one and creating a new
one.
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
createDurableSubscriber
method except that it returns a
MessageConsumer
rather than a TopicSubscriber
to
represent the consumer.
topic
- the non-temporary Topic
to subscribe toname
- the name used to identify this subscriptionInvalidDestinationException
- if an invalid topic is specified.IllegalStateException
- if the client identifier is unsetJMSException
- MessageConsumer
due to some
internal error
MessageConsumer createDurableConsumer(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 JMS 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 unshared durable subscriptions. Any
durable subscription created using this method will be unshared. 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 unshared 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, message selector and
noLocal
value has been specified, and there is no consumer
already active (i.e. not closed) on the durable subscription then
this method creates a MessageConsumer
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, 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 then this is
equivalent to unsubscribing (deleting) the old one and creating a new
one.
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.
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
createDurableSubscriber
method except that it returns a
MessageConsumer
rather than a TopicSubscriber
to
represent the consumer.
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 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.IllegalStateException
- if the client identifier is unsetJMSException
- MessageConsumer
due to some
internal error
MessageConsumer createSharedDurableConsumer(Topic topic, java.lang.String name) throws JMSException
noLocal
parameter, and creates a consumer on that durable subscription. This
method creates the durable subscription without a message selector.
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 JMS 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 shared durable subscriptions. Any
durable subscription created using this method will be shared. This means
that multiple active (i.e. not closed) consumers on the subscription may
exist at the same time. The term "consumer" here means a
MessageConsumer
or JMSConsumer
object in any client.
A shared durable subscription is identified by a name specified by the client and by the client identifier (which may be unset). An application which subsequently wishes to create a consumer on that shared durable subscription must use the same client identifier.
If a shared durable subscription already exists with the same name and
client identifier (if set), and the same topic and message selector
has been specified, then this method creates a
MessageConsumer
on the existing shared durable subscription.
If a shared durable subscription already exists with the same name and client identifier (if set) but a different topic or message selector has been specified, and there is no consumer already active (i.e. not closed) on the durable subscription then this is equivalent to unsubscribing (deleting) the old one and creating a new one.
If a shared durable subscription already exists with the same name and
client identifier (if set) but a different topic or message selector
has been specified, and there is a consumer already
active (i.e. not closed) on the durable subscription, then a
JMSException
will be thrown.
A shared durable subscription and an unshared durable subscription may
not have the same name and client identifier (if set). If an unshared
durable subscription already exists with the same name and client
identifier (if set) then a JMSException
is thrown.
There is no restriction on durable subscriptions and shared non-durable subscriptions having the same name and clientId (which may be unset). Such subscriptions would be completely separate.
topic
- the non-temporary Topic
to subscribe toname
- the name used to identify this subscriptionJMSException
- MessageConsumer
due to some
internal error
InvalidDestinationException
- if an invalid topic is specified.MessageConsumer createSharedDurableConsumer(Topic topic, java.lang.String name, java.lang.String messageSelector) throws JMSException
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 JMS 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 shared durable subscriptions. Any
durable subscription created using this method will be shared. This means
that multiple active (i.e. not closed) consumers on the subscription may
exist at the same time. The term "consumer" here means a
MessageConsumer
or JMSConsumer
object in any client.
A shared durable subscription is identified by a name specified by the client and by the client identifier (which may be unset). An application which subsequently wishes to create a consumer on that shared durable subscription must use the same client identifier.
If a shared durable subscription already exists with the same name and
client identifier (if set), and the same topic and message selector
has been specified, then this method creates a
MessageConsumer
on the existing shared durable subscription.
If a shared durable subscription already exists with the same name and client identifier (if set) but a different topic or message selector has been specified, and there is no consumer already active (i.e. not closed) on the durable subscription then this is equivalent to unsubscribing (deleting) the old one and creating a new one.
If a shared durable subscription already exists with the same name and
client identifier (if set) but a different topic or message selector
has been specified, and there is a consumer already
active (i.e. not closed) on the durable subscription, then a
JMSException
will be thrown.
A shared durable subscription and an unshared durable subscription may
not have the same name and client identifier (if set). If an unshared
durable subscription already exists with the same name and client
identifier (if set) then a JMSException
is thrown.
There is no restriction on durable subscriptions and shared non-durable subscriptions having the same name and clientId (which may be unset). Such subscriptions would be completely separate.
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 added to the durable subscription. A value of
null or an empty string indicates that there is no message
selector for the durable subscription.JMSException
- MessageConsumer
due to some
internal error
InvalidDestinationException
- if an invalid topic is specified.InvalidSelectorException
- if the message selector is invalid.QueueBrowser createBrowser(Queue queue) throws JMSException
QueueBrowser
object to peek at the messages on
the specified queue.queue
- the queue
to accessJMSException
- if the session fails to create a browser
due to some internal error.InvalidDestinationException
- if an invalid destination
is specifiedQueueBrowser createBrowser(Queue queue, java.lang.String messageSelector) throws JMSException
QueueBrowser
object to peek at the messages on the
specified queue using a message selector.queue
- the queue
to accessmessageSelector
- 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.JMSException
- if the session fails to create a browser due to some
internal error.InvalidDestinationException
- if an invalid destination is specifiedInvalidSelectorException
- if the message selector is invalid.TemporaryQueue createTemporaryQueue() throws JMSException
TemporaryQueue
object. Its lifetime will be that
of the Connection
unless it is deleted earlier.JMSException
- if the session fails to create a temporary queue
due to some internal error.TemporaryTopic createTemporaryTopic() throws JMSException
TemporaryTopic
object. Its lifetime will be that
of the Connection
unless it is deleted earlier.JMSException
- 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.
A durable subscription is identified by a name specified by the client and by the client identifier if set. If the client identifier was set when the durable subscription was created then a client which subsequently wishes to use this method to delete a durable subscription must use the same client identifier.
It is erroneous for a client to delete a durable subscription while there is an active (not closed) consumer for the subscription, or while a consumed message is part of a pending transaction or has not been acknowledged in the session.
name
- 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.