Oracle GlassFish(tm) Server Message Queue
5.0

javax.jms
Interface Connection

All Known Subinterfaces:
Connection, QueueConnection, QueueConnection, TopicConnection, TopicConnection, XAConnection, XAQueueConnection, XATopicConnection

public interface Connection

A Connection object is a client's active connection to its JMS provider. It typically allocates provider resources outside the Java virtual machine (JVM).

Connections support concurrent use.

A connection serves several purposes:

Because the creation of a connection involves setting up authentication and communication, a connection is a relatively heavyweight object. Most clients will do all their messaging with a single connection. Other more advanced applications may use several connections. The JMS API does not architect a reason for using multiple connections; however, there may be operational reasons for doing so.

A JMS client typically creates a connection, one or more sessions, and a number of message producers and consumers. When a connection is created, it is in stopped mode. That means that no messages are being delivered.

It is typical to leave the connection in stopped mode until setup is complete (that is, until all message consumers have been created). At that point, the client calls the connection's start method, and messages begin arriving at the connection's consumers. This setup convention minimizes any client confusion that may result from asynchronous message delivery while the client is still in the process of setting itself up.

A connection can be started immediately, and the setup can be done afterwards. Clients that do this must be prepared to handle asynchronous message delivery while they are still in the process of setting up.

A message producer can send messages while a connection is stopped.

See Also:
ConnectionFactory, QueueConnection, TopicConnection

Method Summary
 void close()
          Closes the connection.
 ConnectionConsumer createConnectionConsumer(Destination destination, java.lang.String messageSelector, ServerSessionPool sessionPool, int maxMessages)
          Creates a connection consumer for this connection (optional operation) on the specific destination.
 ConnectionConsumer createDurableConnectionConsumer(Topic topic, java.lang.String subscriptionName, java.lang.String messageSelector, ServerSessionPool sessionPool, int maxMessages)
          Creates a connection consumer for this connection (optional operation) on the specific topic using an unshared durable subscription with the specified name.
 Session createSession()
          Creates a Session object, specifying no arguments.
 Session createSession(boolean transacted, int acknowledgeMode)
          Creates a Session object, specifying transacted and acknowledgeMode.
 Session createSession(int sessionMode)
          Creates a Session object, specifying sessionMode.
 ConnectionConsumer createSharedConnectionConsumer(Topic topic, java.lang.String subscriptionName, java.lang.String messageSelector, ServerSessionPool sessionPool, int maxMessages)
          Creates a connection consumer for this connection (optional operation) on the specific topic using a shared non-durable subscription with the specified name.
 ConnectionConsumer createSharedDurableConnectionConsumer(Topic topic, java.lang.String subscriptionName, java.lang.String messageSelector, ServerSessionPool sessionPool, int maxMessages)
          Creates a connection consumer for this connection (optional operation) on the specific topic using a shared durable subscription with the specified name.
 java.lang.String getClientID()
          Gets the client identifier for this connection.
 ExceptionListener getExceptionListener()
          Gets the ExceptionListener object for this connection.
 ConnectionMetaData getMetaData()
          Gets the metadata for this connection.
 void setClientID(java.lang.String clientID)
          Sets the client identifier for this connection.
 void setExceptionListener(ExceptionListener listener)
          Sets an exception listener for this connection.
 void start()
          Starts (or restarts) a connection's delivery of incoming messages.
 void stop()
          Temporarily stops a connection's delivery of incoming messages.
 

Method Detail

createSession

Session createSession(boolean transacted,
                      int acknowledgeMode)
                      throws JMSException
Creates a Session object, specifying transacted and acknowledgeMode.

This method has been superseded by the method createSession(int sessionMode) which specifies the same information using a single argument, and by the method createSession() which is for use in a Java EE JTA transaction. Applications should consider using those methods instead of this one.

The effect of setting the transacted and acknowledgeMode arguments depends on whether this method is called in a Java SE environment, in the Java EE application client container, or in the Java EE web or EJB container. If this method is called in the Java EE web or EJB container then the effect of setting the transacted} and acknowledgeMode arguments also depends on whether or not there is an active JTA transaction in progress.

In a Java SE environment or in the Java EE application client container:

In a Java EE web or EJB container, when there is an active JTA transaction in progress:

In the Java EE web or EJB container, when there is no active JTA transaction in progress:

Applications running in the Java EE web and EJB containers must not attempt to create more than one active (not closed) Session object per connection. If this method is called in a Java EE web or EJB container when an active Session object already exists for this connection then a JMSException will be thrown.

Parameters:
transacted - indicates whether the session will use a local transaction. If this method is called in the Java EE web or EJB container then this argument is ignored.
acknowledgeMode - indicates how messages received by the session will be acknowledged.
  • If this method is called in a Java SE environment or in the Java EE application client container, the permitted values are Session.CLIENT_ACKNOWLEDGE, Session.AUTO_ACKNOWLEDGE and Session.DUPS_OK_ACKNOWLEDGE.
  • If this method is called in the Java EE web or EJB container when there is an active JTA transaction in progress then this argument is ignored.
  • If this method is called in the Java EE web or EJB container when there is no active JTA transaction in progress, the permitted values are Session.AUTO_ACKNOWLEDGE and Session.DUPS_OK_ACKNOWLEDGE. In this case Session.CLIENT_ACKNOWLEDGE is not permitted.
Returns:
a newly created session
Throws:
JMSException - if the Connection object fails to create a session due to
  • some internal error,
  • lack of support for the specific transaction and acknowledgement mode, or
  • because this method is being called in a Java EE web or EJB application and an active session already exists for this connection.
Since:
1.1
See Also:
Session.AUTO_ACKNOWLEDGE, Session.CLIENT_ACKNOWLEDGE, Session.DUPS_OK_ACKNOWLEDGE, createSession(int), createSession()

createSession

Session createSession(int sessionMode)
                      throws JMSException
Creates a Session object, specifying sessionMode.

The effect of setting the sessionMode argument depends on whether this method is called in a Java SE environment, in the Java EE application client container, or in the Java EE web or EJB container. If this method is called in the Java EE web or EJB container then the effect of setting the sessionMode argument also depends on whether or not there is an active JTA transaction in progress.

In a Java SE environment or in the Java EE application client container:

In a Java EE web or EJB container, when there is an active JTA transaction in progress:

In the Java EE web or EJB container, when there is no active JTA transaction in progress:

Applications running in the Java EE web and EJB containers must not attempt to create more than one active (not closed) Session object per connection. If this method is called in a Java EE web or EJB container when an active Session object already exists for this connection then a JMSException will be thrown.

Parameters:
sessionMode - indicates which of four possible session modes will be used.
  • If this method is called in a Java SE environment or in the Java EE application client container, the permitted values are Session.SESSION_TRANSACTED, Session.CLIENT_ACKNOWLEDGE, Session.AUTO_ACKNOWLEDGE and Session.DUPS_OK_ACKNOWLEDGE.
  • If this method is called in the Java EE web or EJB container when there is an active JTA transaction in progress then this argument is ignored.
  • If this method is called in the Java EE web or EJB container when there is no active JTA transaction in progress, the permitted values are Session.AUTO_ACKNOWLEDGE and Session.DUPS_OK_ACKNOWLEDGE. In this case the values Session.TRANSACTED and Session.CLIENT_ACKNOWLEDGE are not permitted.
Returns:
a newly created session
Throws:
JMSException - if the Connection object fails to create a session due to
  • some internal error,
  • lack of support for the specific transaction and acknowledgement mode, or
  • because this method is being called in a Java EE web or EJB application and an active session already exists for this connection.
Since:
2.0
See Also:
Session.SESSION_TRANSACTED, Session.AUTO_ACKNOWLEDGE, Session.CLIENT_ACKNOWLEDGE, Session.DUPS_OK_ACKNOWLEDGE, createSession(boolean, int), createSession()

createSession

Session createSession()
                      throws JMSException
Creates a Session object, specifying no arguments.

The behaviour of the session that is created depends on whether this method is called in a Java SE environment, in the Java EE application client container, or in the Java EE web or EJB container. If this method is called in the Java EE web or EJB container then the behaviour of the session also depends on whether or not there is an active JTA transaction in progress.

In a Java SE environment or in the Java EE application client container:

In a Java EE web or EJB container, when there is an active JTA transaction in progress:

In the Java EE web or EJB container, when there is no active JTA transaction in progress:

Applications running in the Java EE web and EJB containers must not attempt to create more than one active (not closed) Session object per connection. If this method is called in a Java EE web or EJB container when an active Session object already exists for this connection then a JMSException will be thrown.

Returns:
a newly created session
Throws:
JMSException - if the Connection object fails to create a session due to
  • some internal error or
  • because this method is being called in a Java EE web or EJB application and an active session already exists for this connection.
Since:
2.0
See Also:
Session.AUTO_ACKNOWLEDGE, createSession(boolean, int), createSession(int)

getClientID

java.lang.String getClientID()
                             throws JMSException
Gets the client identifier for this connection.

This value is specific to the JMS provider. It is either preconfigured by an administrator in a ConnectionFactory object or assigned dynamically by the application by calling the setClientID method.

Returns:
the unique client identifier
Throws:
JMSException - if the JMS provider fails to return the client ID for this connection due to some internal error.

setClientID

void setClientID(java.lang.String clientID)
                 throws JMSException
Sets the client identifier for this connection.

The preferred way to assign a JMS client's client identifier is for it to be configured in a client-specific ConnectionFactory object and transparently assigned to the Connection object it creates.

Alternatively, a client can set a connection's client identifier using a provider-specific value. The facility to set a connection's client identifier explicitly is not a mechanism for overriding the identifier that has been administratively configured. It is provided for the case where no administratively specified identifier exists. If one does exist, an attempt to change it by setting it must throw an IllegalStateException. If a client sets the client identifier explicitly, it must do so immediately after it creates the connection and before any other action on the connection is taken. After this point, setting the client identifier is a programming error that should throw an IllegalStateException.

The purpose of the client identifier is to associate a connection and its objects with a state maintained on behalf of the client by a provider. The only such state identified by the JMS API is that required to support durable subscriptions.

If another connection with the same clientID is already running when this method is called, the JMS provider should detect the duplicate ID and throw an InvalidClientIDException.

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.

Parameters:
clientID - the unique client identifier
Throws:
JMSException - if the JMS provider fails to set the client ID for the the connection for one of the following reasons:
  • an internal error has occurred or
  • 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)
InvalidClientIDException - if the JMS client specifies an invalid or duplicate client ID.
IllegalStateException - if the JMS client attempts to set a connection's client ID at the wrong time or when it has been administratively configured.

getMetaData

ConnectionMetaData getMetaData()
                               throws JMSException
Gets the metadata for this connection.

Returns:
the connection metadata
Throws:
JMSException - if the JMS provider fails to get the connection metadata for this connection.
See Also:
ConnectionMetaData

getExceptionListener

ExceptionListener getExceptionListener()
                                       throws JMSException
Gets the ExceptionListener object for this connection. Not every Connection has an ExceptionListener associated with it.

Returns:
the ExceptionListener for this connection, or null. if no ExceptionListener is associated with this connection.
Throws:
JMSException - if the JMS provider fails to get the ExceptionListener for this connection.
See Also:
setExceptionListener(javax.jms.ExceptionListener)

setExceptionListener

void setExceptionListener(ExceptionListener listener)
                          throws JMSException
Sets an exception listener for this connection.

If a JMS provider detects a serious problem with a connection, it informs the connection's ExceptionListener, if one has been registered. It does this by calling the listener's onException method, passing it a JMSException object describing the problem.

An exception listener allows a client to be notified of a problem asynchronously. Some connections only consume messages, so they would have no other way to learn their connection has failed.

A connection serializes execution of its ExceptionListener.

A JMS provider should attempt to resolve connection problems itself before it notifies the client of them.

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.

Parameters:
listener - the exception listener
Throws:
JMSException - if the JMS provider fails to set the exception listener for one of the following reasons:
  • an internal error has occurred or
  • 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)

start

void start()
           throws JMSException
Starts (or restarts) a connection's delivery of incoming messages. A call to start on a connection that has already been started is ignored.

Throws:
JMSException - if the JMS provider fails to start message delivery due to some internal error.
See Also:
stop()

stop

void stop()
          throws JMSException
Temporarily stops a connection's delivery of incoming messages. Delivery can be restarted using the connection's start method. When the connection is stopped, delivery to all the connection's message consumers is inhibited: synchronous receives block, and messages are not delivered to message listeners.

This call blocks until receives and/or message listeners in progress have completed.

Stopping a connection has no effect on its ability to send messages. A call to stop on a connection that has already been stopped is ignored.

A call to stop must not return until delivery of messages has paused. This means that a client can rely on the fact that none of its message listeners will be called and that all threads of control waiting for receive calls to return will not return with a message until the connection is restarted. The receive timers for a stopped connection continue to advance, so receives may time out while the connection is stopped.

If message listeners are running when stop is invoked, the stop call must wait until all of them have returned before it may return. While these message listeners are completing, they must have the full services of the connection available to them.

A message listener must not attempt to stop its own connection as this would lead to deadlock. The JMS provider must detect this and throw a IllegalStateException.

For the avoidance of doubt, if an exception listener for this connection is running when stop is invoked, there is no requirement for the stop call to wait until the exception listener has returned before it may return.

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.

Throws:
IllegalStateException - this method has been called by a MessageListener on its own Connection
JMSException - if the JMS provider fails to stop message delivery for one of the following reasons:
  • an internal error has occurred or
  • 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)
See Also:
start()

close

void close()
           throws JMSException
Closes the connection.

Since a provider typically allocates significant resources outside the JVM on behalf of a connection, clients should close these 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 sessions, producers, and consumers of a closed connection.

Closing a connection causes all temporary destinations to be deleted.

When this method is invoked, it should not return until message processing has been shut down in an orderly fashion. This means that all message listeners that may have been running have returned, and that all pending receives have returned. A close terminates all pending message receives on the connection's sessions' consumers. The receives may return with a message or with null, depending on whether there was a message available at the time of the close. If one or more of the connection's sessions' message listeners is processing a message at the time when connection close is invoked, all the facilities of the connection and its sessions must remain available to those listeners until they return control to the JMS provider.

This method must not return until any incomplete asynchronous send operations for this Connection 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 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 connection causes any of its sessions' transactions in progress to be rolled back. In the case where a session's work is coordinated by an external transaction manager, a session's commit and rollback methods are not used and the result of a closed session's work is determined later by the transaction manager. Closing a connection does NOT force an acknowledgment of client-acknowledged sessions.

A message listener must not attempt to close its own connection 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 Connection. Doing so will cause an IllegalStateException to be thrown.

Invoking the acknowledge method of a received message from a closed connection's session must throw an IllegalStateException. Closing a closed connection must NOT throw an exception.

Throws:
IllegalStateException -
  • this method has been called by a MessageListener on its own Connection
  • this method has been called by a CompletionListener callback method on its own Connection
JMSException - if the JMS provider fails to close the connection due to some internal error. For example, a failure to release resources or to close a socket connection can cause this exception to be thrown.

createConnectionConsumer

ConnectionConsumer createConnectionConsumer(Destination destination,
                                            java.lang.String messageSelector,
                                            ServerSessionPool sessionPool,
                                            int maxMessages)
                                            throws JMSException
Creates a connection consumer for this connection (optional operation) on the specific destination.

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.

Parameters:
destination - the destination to access
messageSelector - 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.
sessionPool - the server session pool to associate with this connection consumer
maxMessages - the maximum number of messages that can be assigned to a server session at one time
Returns:
the connection consumer
Throws:
InvalidDestinationException - if an invalid destination is specified.
InvalidSelectorException - if the message selector is invalid.
JMSException - if the Connection object fails to create a connection consumer for one of the following reasons:
  • an internal error has occurred
  • invalid arguments for sessionPool and messageSelector or
  • 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)
Since:
1.1
See Also:
ConnectionConsumer

createSharedConnectionConsumer

ConnectionConsumer createSharedConnectionConsumer(Topic topic,
                                                  java.lang.String subscriptionName,
                                                  java.lang.String messageSelector,
                                                  ServerSessionPool sessionPool,
                                                  int maxMessages)
                                                  throws JMSException
Creates a connection consumer for this connection (optional operation) on the specific topic using a shared non-durable subscription with the specified name.

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.

Parameters:
topic - the topic to access
subscriptionName - the name used to identify the shared non-durable subscription
messageSelector - 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.
sessionPool - the server session pool to associate with this connection consumer
maxMessages - the maximum number of messages that can be assigned to a server session at one time
Returns:
the connection consumer
Throws:
IllegalStateException - if called on a QueueConnection
InvalidDestinationException - if an invalid destination is specified.
InvalidSelectorException - if the message selector is invalid.
JMSException - if the Connection object fails to create a connection consumer for one of the following reasons:
  • an internal error has occurred
  • invalid arguments for sessionPool and messageSelector or
  • 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)
Since:
2.0
See Also:
ConnectionConsumer

createDurableConnectionConsumer

ConnectionConsumer createDurableConnectionConsumer(Topic topic,
                                                   java.lang.String subscriptionName,
                                                   java.lang.String messageSelector,
                                                   ServerSessionPool sessionPool,
                                                   int maxMessages)
                                                   throws JMSException
Creates a connection consumer for this connection (optional operation) on the specific topic using an unshared durable subscription with the specified name.

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.

Parameters:
topic - topic to access
subscriptionName - the name used to identify the unshared durable subscription
messageSelector - 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.
sessionPool - the server session pool to associate with this durable connection consumer
maxMessages - the maximum number of messages that can be assigned to a server session at one time
Returns:
the durable connection consumer
Throws:
IllegalStateException - if called on a QueueConnection
InvalidDestinationException - if an invalid destination is specified.
InvalidSelectorException - if the message selector is invalid.
JMSException - if the Connection object fails to create a connection consumer for one of the following reasons:
  • an internal error has occurred
  • invalid arguments for sessionPool and messageSelector or
  • 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)
Since:
1.1
See Also:
ConnectionConsumer

createSharedDurableConnectionConsumer

ConnectionConsumer createSharedDurableConnectionConsumer(Topic topic,
                                                         java.lang.String subscriptionName,
                                                         java.lang.String messageSelector,
                                                         ServerSessionPool sessionPool,
                                                         int maxMessages)
                                                         throws JMSException
Creates a connection consumer for this connection (optional operation) on the specific topic using a shared durable subscription with the specified name.

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.

Parameters:
topic - topic to access
subscriptionName - the name used to identify the shared durable subscription
messageSelector - 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.
sessionPool - the server session pool to associate with this durable connection consumer
maxMessages - the maximum number of messages that can be assigned to a server session at one time
Returns:
the durable connection consumer
Throws:
IllegalStateException - if called on a QueueConnection
InvalidDestinationException - if an invalid destination is specified.
InvalidSelectorException - if the message selector is invalid.
JMSException - if the Connection object fails to create a connection consumer for one of the following reasons:
  • an internal error has occurred
  • invalid arguments for sessionPool and messageSelector or
  • 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)
Since:
2.0
See Also:
ConnectionConsumer

Oracle GlassFish(tm) Server Message Queue
5.0

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