cms::Session Class Reference

A Session object is a single-threaded context for producing and consuming messages. More...

#include <src/main/cms/Session.h>

Inheritance diagram for cms::Session:

[legend]

Public Types
enum	AcknowledgeMode {   AUTO_ACKNOWLEDGE, DUPS_OK_ACKNOWLEDGE, CLIENT_ACKNOWLEDGE, SESSION_TRANSACTED,   INDIVIDUAL_ACKNOWLEDGE }
Public Member Functions
virtual	~Session ()
virtual void	close ()=0
	Closes this session as well as any active child consumers or producers.
virtual void	commit ()=0
	Commits all messages done in this transaction and releases any locks currently held.
virtual void	rollback ()=0
	Rolls back all messages done in this transaction and releases any locks currently held.
virtual void	recover ()=0
	Stops message delivery in this session, and restarts message delivery with the oldest unacknowledged message.
virtual MessageConsumer *	createConsumer (const Destination *destination)=0
	Creates a MessageConsumer for the specified destination.
virtual MessageConsumer *	createConsumer (const Destination *destination, const std::string &selector)=0
	Creates a MessageConsumer for the specified destination, using a message selector.
virtual MessageConsumer *	createConsumer (const Destination *destination, const std::string &selector, bool noLocal)=0
	Creates a MessageConsumer for the specified destination, using a message selector.
virtual MessageConsumer *	createDurableConsumer (const Topic *destination, const std::string &name, const std::string &selector, bool noLocal=false)=0
	Creates a durable subscriber to the specified topic, using a Message selector.
virtual MessageProducer *	createProducer (const Destination *destination=NULL)=0
	Creates a MessageProducer to send messages to the specified destination.
virtual QueueBrowser *	createBrowser (const cms::Queue *queue)=0
	Creates a new QueueBrowser to peek at Messages on the given Queue.
virtual QueueBrowser *	createBrowser (const cms::Queue *queue, const std::string &selector)=0
	Creates a new QueueBrowser to peek at Messages on the given Queue.
virtual Queue *	createQueue (const std::string &queueName)=0
	Creates a queue identity given a Queue name.
virtual Topic *	createTopic (const std::string &topicName)=0
	Creates a topic identity given a Queue name.
virtual TemporaryQueue *	createTemporaryQueue ()=0
	Creates a TemporaryQueue object.
virtual TemporaryTopic *	createTemporaryTopic ()=0
	Creates a TemporaryTopic object.
virtual Message *	createMessage ()=0
	Creates a new Message.
virtual BytesMessage *	createBytesMessage ()=0
	Creates a BytesMessage.
virtual BytesMessage *	createBytesMessage (const unsigned char *bytes, int bytesSize)=0
	Creates a BytesMessage and sets the payload to the passed value.
virtual StreamMessage *	createStreamMessage ()=0
	Creates a new StreamMessage.
virtual TextMessage *	createTextMessage ()=0
	Creates a new TextMessage.
virtual TextMessage *	createTextMessage (const std::string &text)=0
	Creates a new TextMessage and set the text to the value given.
virtual MapMessage *	createMapMessage ()=0
	Creates a new MapMessage.
virtual AcknowledgeMode	getAcknowledgeMode () const =0
	Returns the acknowledgment mode of the session.
virtual bool	isTransacted () const =0
	Gets if the Sessions is a Transacted Session.
virtual void	unsubscribe (const std::string &name)=0
	Unsubscribes a durable subscription that has been created by a client.
virtual void	setMessageTransformer (cms::MessageTransformer *transformer)=0
	Set an MessageTransformer instance that is passed on to all MessageProducer and MessageConsumer objects created from this Session.
virtual cms::MessageTransformer *	getMessageTransformer () const =0
	Gets the currently configured MessageTransformer for this Session.

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Detailed Description

A Session object is a single-threaded context for producing and consuming messages.

A session serves several purposes:

• It is a factory for its message producers and consumers.
• It supplies provider-optimized message factories.
• It is a factory for TemporaryTopics and TemporaryQueues.
• It provides a way to create Queue or Topic objects for those clients that need to dynamically manipulate provider-specific destination names.
• It supports a single series of transactions that combine work spanning its producers and consumers into atomic units.
• It defines a serial order for the messages it consumes and the messages it produces.
• It retains messages it consumes until they have been acknowledged.
• It serializes execution of message listeners registered with its message consumers.

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 MessageProducers.

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.

Certain rules apply to a session's close method and are detailed below.

• There is no need to close the producers and consumers of a closed session.
• The close 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.
• Closing a transacted session must roll back the transaction in progress.
• The close method is the only Session method that can be called concurrently.
• Invoking any other Session method on a closed session must throw an IllegalStateException. Closing a closed session must not throw any exceptions.

Transacted Sessions

When a Session is created it can be set to operate in a Transaction based mode. Each Session then operates in a single transaction for all Producers and Consumers of that Session. Messages sent and received within a Transaction are grouped into an atomic unit that is committed or rolled back together.

For a MessageProducer this implies that all messages sent by the producer are not sent to the Provider unit the commit call is made. Rolling back the Transaction results in all produced Messages being dropped.

For a MessageConsumer this implies that all received messages are not Acknowledged until the Commit call is made. Rolling back the Transaction results in all Consumed Message being redelivered to the client, the Provider may allow configuration that limits the Maximum number of redeliveries for a Message.

While the Session interface implements the Startable and Stoppable interfaces it is not required to implement these methods and can throw an UnsupportedOperation exception if they are not available for the given CMS provider.

Since:

1.0

---

Member Enumeration Documentation

enum cms::Session::AcknowledgeMode

Enumerator:

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.
DUPS_OK_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. Acknowledgments may be delayed in this mode to increase performance at the cost of the message being redelivered this client fails.
CLIENT_ACKNOWLEDGE	With this acknowledgment mode, the client acknowledges a consumed message by calling the message's acknowledge method.
SESSION_TRANSACTED	Messages will be consumed when the transaction commits.
INDIVIDUAL_ACKNOWLEDGE	Message will be acknowledged individually. Normally the acks sent acknowledge the given message and all messages received before it, this mode only acknowledges one message.

---

Constructor & Destructor Documentation

virtual cms::Session::~Session

(

)

[virtual]

---

Member Function Documentation

virtual void cms::Session::close

(

)

[pure virtual]

Closes this session as well as any active child consumers or producers.

Exceptions:

CMSException

- If an internal error occurs.

Implements cms::Closeable.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, and activemq::core::kernels::ActiveMQSessionKernel.

virtual void cms::Session::commit

(

)

[pure virtual]

Commits all messages done in this transaction and releases any locks currently held.

Exceptions:

	CMSException	- If an internal error occurs.
	IllegalStateException	- if the method is not called by a transacted session.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, activemq::core::ActiveMQXASession, activemq::core::kernels::ActiveMQSessionKernel, and activemq::core::kernels::ActiveMQXASessionKernel.

Referenced by activemq::cmsutil::PooledSession::commit().

virtual QueueBrowser* cms::Session::createBrowser	(	const cms::Queue *	queue,
		const std::string &	selector
	)			[pure virtual]

Creates a new QueueBrowser to peek at Messages on the given Queue.

Parameters:

	queue	the Queue to browse
	selector	the Message selector to filter which messages are browsed.

Returns:

New QueueBrowser that is owned by the caller.

Exceptions:

	CMSException	- If an internal error occurs.
	InvalidDestinationException	- if the destination given is invalid.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, and activemq::core::kernels::ActiveMQSessionKernel.

virtual QueueBrowser* cms::Session::createBrowser

(

const cms::Queue *

queue

)

[pure virtual]

Creates a new QueueBrowser to peek at Messages on the given Queue.

Parameters:

queue

the Queue to browse

Returns:

New QueueBrowser that is owned by the caller.

Exceptions:

	CMSException	- If an internal error occurs.
	InvalidDestinationException	- if the destination given is invalid.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, and activemq::core::kernels::ActiveMQSessionKernel.

virtual BytesMessage* cms::Session::createBytesMessage	(	const unsigned char *	bytes,
		int	bytesSize
	)			[pure virtual]

Creates a BytesMessage and sets the payload to the passed value.

Parameters:

	bytes	an array of bytes to set in the message
	bytesSize	the size of the bytes array, or number of bytes to use

Exceptions:

CMSException

- If an internal error occurs.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, and activemq::core::kernels::ActiveMQSessionKernel.

virtual BytesMessage* cms::Session::createBytesMessage

(

)

[pure virtual]

Creates a BytesMessage.

Exceptions:

CMSException

- If an internal error occurs.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, and activemq::core::kernels::ActiveMQSessionKernel.

Referenced by activemq::cmsutil::PooledSession::createBytesMessage().

virtual MessageConsumer* cms::Session::createConsumer	(	const Destination *	destination,
		const std::string &	selector,
		bool	noLocal
	)			[pure virtual]

Creates a MessageConsumer for the specified destination, using a message selector.

Parameters:

	destination	the Destination that this consumer receiving messages for.
	selector	the Message Selector to use
	noLocal	if true, and the destination is a topic, inhibits the delivery of messages published by its own connection. The behavior for NoLocal is not specified if the destination is a queue.

Returns:

pointer to a new MessageConsumer that is owned by the caller ( caller deletes )

Exceptions:

	CMSException	- If an internal error occurs.
	InvalidDestinationException	- if an invalid destination is specified.
	InvalidSelectorException	- if the message selector is invalid.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, and activemq::core::kernels::ActiveMQSessionKernel.

virtual MessageConsumer* cms::Session::createConsumer	(	const Destination *	destination,
		const std::string &	selector
	)			[pure virtual]

Creates a MessageConsumer for the specified destination, using a message selector.

Parameters:

	destination	the Destination that this consumer receiving messages for.
	selector	the Message Selector to use

Returns:

pointer to a new MessageConsumer that is owned by the caller ( caller deletes )

Exceptions:

	CMSException	- If an internal error occurs.
	InvalidDestinationException	- if an invalid destination is specified.
	InvalidSelectorException	- if the message selector is invalid.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, and activemq::core::kernels::ActiveMQSessionKernel.

virtual MessageConsumer* cms::Session::createConsumer

(

const Destination *

destination

)

[pure virtual]

Creates a MessageConsumer for the specified destination.

Parameters:

destination

the Destination that this consumer receiving messages for.

Returns:

pointer to a new MessageConsumer that is owned by the caller ( caller deletes )

Exceptions:

	CMSException	- If an internal error occurs.
	InvalidDestinationException	- if an invalid destination is specified.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, and activemq::core::kernels::ActiveMQSessionKernel.

Referenced by activemq::cmsutil::PooledSession::createConsumer().

virtual MessageConsumer* cms::Session::createDurableConsumer	(	const Topic *	destination,
		const std::string &	name,
		const std::string &	selector,
		bool	noLocal = false
	)			[pure virtual]

Creates a durable subscriber to the specified topic, using a Message selector.

Sessions that create durable consumers must use the same client Id as was used the last time the subscription was created in order to receive all messages that were delivered while the client was offline.

Parameters:

	destination	the topic to subscribe to
	name	The name used to identify the subscription
	selector	the Message Selector to use
	noLocal	if true, and the destination is a topic, inhibits the delivery of messages published by its own connection. The behavior for NoLocal is not specified if the destination is a queue.

Returns:

pointer to a new durable MessageConsumer that is owned by the caller ( caller deletes )

Exceptions:

	CMSException	- If an internal error occurs.
	InvalidDestinationException	- if an invalid destination is specified.
	InvalidSelectorException	- if the message selector is invalid.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, and activemq::core::kernels::ActiveMQSessionKernel.

Referenced by activemq::cmsutil::PooledSession::createDurableConsumer().

virtual MapMessage* cms::Session::createMapMessage

(

)

[pure virtual]

Creates a new MapMessage.

Exceptions:

CMSException

- If an internal error occurs.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, and activemq::core::kernels::ActiveMQSessionKernel.

Referenced by activemq::cmsutil::PooledSession::createMapMessage().

virtual Message* cms::Session::createMessage

(

)

[pure virtual]

Creates a new Message.

Exceptions:

CMSException

- If an internal error occurs.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, and activemq::core::kernels::ActiveMQSessionKernel.

Referenced by activemq::cmsutil::PooledSession::createMessage().

virtual MessageProducer* cms::Session::createProducer

(

const Destination *

destination = NULL

)

[pure virtual]

Creates a MessageProducer to send messages to the specified destination.

Parameters:

destination

the Destination to send on

Returns:

New MessageProducer that is owned by the caller.

Exceptions:

	CMSException	- If an internal error occurs.
	InvalidDestinationException	- if an invalid destination is specified.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, and activemq::core::kernels::ActiveMQSessionKernel.

Referenced by activemq::cmsutil::PooledSession::createProducer().

virtual Queue* cms::Session::createQueue

(

const std::string &

queueName

)

[pure virtual]

Creates a queue identity given a Queue name.

Parameters:

queueName

the name of the new Queue

Returns:

new Queue pointer that is owned by the caller.

Exceptions:

CMSException

- If an internal error occurs.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, and activemq::core::kernels::ActiveMQSessionKernel.

Referenced by activemq::cmsutil::PooledSession::createQueue().

virtual StreamMessage* cms::Session::createStreamMessage

(

)

[pure virtual]

Creates a new StreamMessage.

Exceptions:

CMSException

- If an internal error occurs.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, and activemq::core::kernels::ActiveMQSessionKernel.

Referenced by activemq::cmsutil::PooledSession::createStreamMessage().

virtual TemporaryQueue* cms::Session::createTemporaryQueue

(

)

[pure virtual]

Creates a TemporaryQueue object.

Returns:

new TemporaryQueue pointer that is owned by the caller.

Exceptions:

CMSException

- If an internal error occurs.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, and activemq::core::kernels::ActiveMQSessionKernel.

Referenced by activemq::cmsutil::PooledSession::createTemporaryQueue().

virtual TemporaryTopic* cms::Session::createTemporaryTopic

(

)

[pure virtual]

Creates a TemporaryTopic object.

Exceptions:

CMSException

- If an internal error occurs.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, and activemq::core::kernels::ActiveMQSessionKernel.

Referenced by activemq::cmsutil::PooledSession::createTemporaryTopic().

virtual TextMessage* cms::Session::createTextMessage

(

const std::string &

text

)

[pure virtual]

Creates a new TextMessage and set the text to the value given.

Parameters:

text

the initial text for the message

Exceptions:

CMSException

- If an internal error occurs.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, and activemq::core::kernels::ActiveMQSessionKernel.

virtual TextMessage* cms::Session::createTextMessage

(

)

[pure virtual]

Creates a new TextMessage.

Exceptions:

CMSException

- If an internal error occurs.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, and activemq::core::kernels::ActiveMQSessionKernel.

Referenced by activemq::cmsutil::PooledSession::createTextMessage().

virtual Topic* cms::Session::createTopic

(

const std::string &

topicName

)

[pure virtual]

Creates a topic identity given a Queue name.

Parameters:

topicName

the name of the new Topic

Returns:

new Topic pointer that is owned by the caller.

Exceptions:

CMSException

- If an internal error occurs.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, and activemq::core::kernels::ActiveMQSessionKernel.

Referenced by activemq::cmsutil::PooledSession::createTopic().

virtual AcknowledgeMode cms::Session::getAcknowledgeMode

(

)

const [pure virtual]

Returns the acknowledgment mode of the session.

Returns:

the Sessions Acknowledge Mode

Exceptions:

CMSException

- If an internal error occurs.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, and activemq::core::kernels::ActiveMQSessionKernel.

Referenced by activemq::cmsutil::PooledSession::getAcknowledgeMode().

virtual cms::MessageTransformer* cms::Session::getMessageTransformer

(

)

const [pure virtual]

Gets the currently configured MessageTransformer for this Session.

Returns:

the pointer to the currently set cms::MessageTransformer.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, and activemq::core::kernels::ActiveMQSessionKernel.

Referenced by activemq::cmsutil::PooledSession::getMessageTransformer().

virtual bool cms::Session::isTransacted

(

)

const [pure virtual]

Gets if the Sessions is a Transacted Session.

Returns:

transacted true - false.

Exceptions:

CMSException

- If an internal error occurs.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, activemq::core::ActiveMQXASession, activemq::core::kernels::ActiveMQSessionKernel, and activemq::core::kernels::ActiveMQXASessionKernel.

Referenced by activemq::cmsutil::PooledSession::isTransacted().

virtual void cms::Session::recover

(

)

[pure virtual]

Stops message delivery in this session, and restarts message delivery with the oldest unacknowledged message.

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:

• Stop message delivery
• Mark all messages that might have been delivered but not acknowledged as "redelivered"
• Restart the delivery sequence including all unacknowledged messages that had been previously delivered. Redelivered messages do not have to be delivered in exactly their original delivery order.

Exceptions:

	CMSException	- if the CMS provider fails to stop and restart message delivery due to some internal error.
	IllegalStateException	- if the method is called by a transacted session.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, and activemq::core::kernels::ActiveMQSessionKernel.

Referenced by activemq::cmsutil::PooledSession::recover().

virtual void cms::Session::rollback

(

)

[pure virtual]

Rolls back all messages done in this transaction and releases any locks currently held.

Exceptions:

	CMSException	- If an internal error occurs.
	IllegalStateException	- if the method is not called by a transacted session.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, activemq::core::ActiveMQXASession, activemq::core::kernels::ActiveMQSessionKernel, and activemq::core::kernels::ActiveMQXASessionKernel.

Referenced by activemq::cmsutil::PooledSession::rollback().

virtual void cms::Session::setMessageTransformer

(

cms::MessageTransformer *

transformer

)

[pure virtual]

Set an MessageTransformer instance that is passed on to all MessageProducer and MessageConsumer objects created from this Session.

The CMS code never takes ownership of the MessageTransformer pointer which implies that the client code must ensure that the object remains valid for the lifetime of the CMS object to which the MessageTransformer has been assigned.

Parameters:

transformer

Pointer to the cms::MessageTransformer to set on all MessageConsumers and MessageProducers.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, and activemq::core::kernels::ActiveMQSessionKernel.

Referenced by activemq::cmsutil::PooledSession::setMessageTransformer().

virtual void cms::Session::unsubscribe

(

const std::string &

name

)

[pure virtual]

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 MessageConsumer or Subscriber for the subscription, or while a consumed message is part of a pending transaction or has not been acknowledged in the session.

Parameters:

name

The name used to identify this subscription

Exceptions:

CMSException

- If an internal error occurs.

Implemented in activemq::cmsutil::PooledSession, activemq::core::ActiveMQSession, and activemq::core::kernels::ActiveMQSessionKernel.

Referenced by activemq::cmsutil::PooledSession::unsubscribe().

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The documentation for this class was generated from the following file:

• src/main/cms/Session.h