public interface MessageProducer extends AutoCloseable
MessageProducer
object to send messages to a destination. A MessageProducer
object is
created by passing a Destination
object to a message-producer creation method supplied by a session.
MessageProducer
is the parent interface for all message producers.
A client also has the option of creating a message producer without supplying a destination. In this case, a
destination must be provided with every send operation. A typical use for this kind of message producer is to send
replies to requests using the request's JMSReplyTo
destination.
A client can specify a default delivery mode, priority, time to live and delivery delay for messages sent by a message producer. It can also specify the delivery mode, priority, and time to live for an individual message.
A client can specify a time-to-live value in milliseconds for each message it sends. This value defines a message expiration time that is the sum of the message's time-to-live and the GMT when it is sent (for transacted sends, this is the time the client sends the message, not the time the transaction is committed).
A Jakarta Messaging provider should do its best to expire messages accurately; however, the Jakarta Messaging API does not define the accuracy provided.
TopicPublisher
,
QueueSender
,
Session.createProducer(javax.jms.Destination)
Modifier and Type | Method and Description |
---|---|
void |
close()
Closes the message producer.
|
long |
getDeliveryDelay()
Gets the minimum length of time in milliseconds that must elapse after a message is sent before the Jakarta Messaging provider may
deliver the message to a consumer.
|
int |
getDeliveryMode()
Gets the producer's default delivery mode.
|
Destination |
getDestination()
Gets the destination associated with this
MessageProducer . |
boolean |
getDisableMessageID()
Gets an indication of whether message IDs are disabled.
|
boolean |
getDisableMessageTimestamp()
Gets an indication of whether message timestamps are disabled.
|
int |
getPriority()
Gets the producer's default priority.
|
long |
getTimeToLive()
Gets the default length of time in milliseconds from its dispatch time that a produced message should be retained by
the message system.
|
void |
send(Destination destination,
Message message)
Sends a message to a destination for an unidentified message producer using the
MessageProducer 's default
delivery mode, priority, and time to live. |
void |
send(Destination destination,
Message message,
CompletionListener completionListener)
Sends a message to a destination for an unidentified message producer, using the
MessageProducer 's default
delivery mode, priority, and time to live, performing part of the work involved in sending the message in a separate
thread and notifying the specified CompletionListener when the operation has completed. |
void |
send(Destination destination,
Message message,
int deliveryMode,
int priority,
long timeToLive)
Sends a message to a destination for an unidentified message producer, specifying delivery mode, priority and time to
live.
|
void |
send(Destination destination,
Message message,
int deliveryMode,
int priority,
long timeToLive,
CompletionListener completionListener)
Sends a message to a destination for an unidentified message producer, specifying delivery mode, priority and time to
live, performing part of the work involved in sending the message in a separate thread and notifying the specified
CompletionListener when the operation has completed.
|
void |
send(Message message)
Sends a message using the
MessageProducer 's default delivery mode, priority, and time to live. |
void |
send(Message message,
CompletionListener completionListener)
Sends a message using the
MessageProducer 's default delivery mode, priority, and time to live, performing
part of the work involved in sending the message in a separate thread and notifying the specified
CompletionListener when the operation has completed. |
void |
send(Message message,
int deliveryMode,
int priority,
long timeToLive)
Sends a message, specifying delivery mode, priority, and time to live.
|
void |
send(Message message,
int deliveryMode,
int priority,
long timeToLive,
CompletionListener completionListener)
Sends a message, specifying delivery mode, priority and time to live, performing part of the work involved in sending
the message in a separate thread and notifying the specified CompletionListener when the operation has
completed.
|
void |
setDeliveryDelay(long deliveryDelay)
Sets the minimum length of time in milliseconds that must elapse after a message is sent before the Jakarta Messaging provider may
deliver the message to a consumer.
|
void |
setDeliveryMode(int deliveryMode)
Sets the producer's default delivery mode.
|
void |
setDisableMessageID(boolean value)
Specify whether message IDs may be disabled.
|
void |
setDisableMessageTimestamp(boolean value)
Specify whether message timestamps may be disabled.
|
void |
setPriority(int defaultPriority)
Sets the producer's default priority.
|
void |
setTimeToLive(long timeToLive)
Sets the default length of time in milliseconds from its dispatch time that a produced message should be retained by
the message system.
|
void setDisableMessageID(boolean value) throws JMSException
Since message IDs take some effort to create and increase a message's size, some Jakarta Messaging providers may be able to
optimise message overhead if they are given a hint that the message ID is not used by an application. By calling this
method, a Jakarta Messaging application enables this potential optimisation for all messages sent using this
MessageProducer
. If the Jakarta Messaging provider accepts this hint, these messages must have the message ID set to null;
if the provider ignores the hint, the message ID must be set to its normal unique value.
Message IDs are enabled by default.
value
- indicates if message IDs may be disabledJMSException
- if the Jakarta Messaging provider fails to set message ID to disabled due to some internal error.boolean getDisableMessageID() throws JMSException
JMSException
- if the Jakarta Messaging provider fails to determine if message IDs are disabled due to some internal
error.void setDisableMessageTimestamp(boolean value) throws JMSException
Since timestamps take some effort to create and increase a message's size, some Jakarta Messaging providers may be able to optimise
message overhead if they are given a hint that the timestamp is not used by an application. By calling this method, a
Jakarta Messaging application enables this potential optimisation for all messages sent using this MessageProducer
. If the
Jakarta Messaging provider accepts this hint, these messages must have the timestamp set to zero; if the provider ignores the hint,
the timestamp must be set to its normal value.
Message timestamps are enabled by default.
value
- indicates whether message timestamps may be disabledJMSException
- if the Jakarta Messaging provider fails to set timestamps to disabled due to some internal error.boolean getDisableMessageTimestamp() throws JMSException
JMSException
- if the Jakarta Messaging provider fails to determine if timestamps are disabled due to some internal error.void setDeliveryMode(int deliveryMode) throws JMSException
Delivery mode is set to PERSISTENT
by default.
deliveryMode
- the message delivery mode for this message producer; legal values are
DeliveryMode.NON_PERSISTENT
and DeliveryMode.PERSISTENT
JMSException
- if the Jakarta Messaging provider fails to set the delivery mode due to some internal error.getDeliveryMode()
,
DeliveryMode.NON_PERSISTENT
,
DeliveryMode.PERSISTENT
,
Message.DEFAULT_DELIVERY_MODE
int getDeliveryMode() throws JMSException
JMSException
- if the Jakarta Messaging provider fails to get the delivery mode due to some internal error.setDeliveryMode(int)
void setPriority(int defaultPriority) throws JMSException
The Jakarta Messaging API defines ten levels of priority value, with 0 as the lowest priority and 9 as the highest. Clients should consider priorities 0-4 as gradations of normal priority and priorities 5-9 as gradations of expedited priority. Priority is set to 4 by default.
defaultPriority
- the message priority for this message producer; must be a value between 0 and 9JMSException
- if the Jakarta Messaging provider fails to set the priority due to some internal error.getPriority()
,
Message.DEFAULT_PRIORITY
int getPriority() throws JMSException
JMSException
- if the Jakarta Messaging provider fails to get the priority due to some internal error.setPriority(int)
void setTimeToLive(long timeToLive) throws JMSException
Time to live is set to zero by default.
timeToLive
- the message time to live in milliseconds; zero is unlimitedJMSException
- if the Jakarta Messaging provider fails to set the time to live due to some internal error.getTimeToLive()
,
Message.DEFAULT_TIME_TO_LIVE
long getTimeToLive() throws JMSException
JMSException
- if the Jakarta Messaging provider fails to get the time to live due to some internal error.setTimeToLive(long)
void setDeliveryDelay(long deliveryDelay) throws JMSException
For transacted sends, this time starts when the client sends the message, not when the transaction is committed.
deliveryDelay is set to zero by default.
deliveryDelay
- the delivery delay in milliseconds.JMSException
- if the Jakarta Messaging provider fails to set the delivery delay due to some internal error.getDeliveryDelay()
,
Message.DEFAULT_DELIVERY_DELAY
long getDeliveryDelay() throws JMSException
JMSException
- if the Jakarta Messaging provider fails to get the delivery delay due to some internal error.setDeliveryDelay(long)
Destination getDestination() throws JMSException
MessageProducer
.Destination
JMSException
- if the Jakarta Messaging provider fails to get the destination for this MessageProducer
due to some
internal error.void close() throws JMSException
Since a provider may allocate some resources on behalf of a MessageProducer
outside the Java virtual machine,
clients should close them when they are not needed. Relying on garbage collection to eventually reclaim these
resources may not be timely enough.
This method must not return until any incomplete asynchronous send operations for this MessageProducer 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 close on its own MessageProducer. Doing so will cause an IllegalStateException to be thrown.
close
in interface AutoCloseable
IllegalStateException
- this method has been called by a CompletionListener callback method on its
own MessageProducerJMSException
- if the Jakarta Messaging provider fails to close the producer due to some internal error.void send(Message message) throws JMSException
MessageProducer
's default delivery mode, priority, and time to live.message
- the message to sendJMSException
- if the Jakarta Messaging provider fails to send the message due to some internal error.MessageFormatException
- if an invalid message is specified.InvalidDestinationException
- if a client uses this method with a MessageProducer
with an invalid
destination.UnsupportedOperationException
- if a client uses this method with a MessageProducer
that
did not specify a destination at creation time.Session.createProducer(javax.jms.Destination)
void send(Message message, int deliveryMode, int priority, long timeToLive) throws JMSException
message
- the message to senddeliveryMode
- the delivery mode to usepriority
- the priority for this messagetimeToLive
- the message's lifetime (in milliseconds)JMSException
- if the Jakarta Messaging provider fails to send the message due to some internal error.MessageFormatException
- if an invalid message is specified.InvalidDestinationException
- if a client uses this method with a MessageProducer
with an invalid
destination.UnsupportedOperationException
- if a client uses this method with a MessageProducer
that
did not specify a destination at creation time.Session.createProducer(javax.jms.Destination)
void send(Destination destination, Message message) throws JMSException
MessageProducer
's default
delivery mode, priority, and time to live.
Typically, a message producer is assigned a destination at creation time; however, the Jakarta Messaging API also supports unidentified message producers, which require that the destination be supplied every time a message is sent.
destination
- the destination to send this message tomessage
- the message to sendJMSException
- if the Jakarta Messaging provider fails to send the message due to some internal error.MessageFormatException
- if an invalid message is specified.InvalidDestinationException
- if a client uses this method with an invalid destination.UnsupportedOperationException
- if a client uses this method with a MessageProducer
that
specified a destination at creation time.Session.createProducer(javax.jms.Destination)
void send(Destination destination, Message message, int deliveryMode, int priority, long timeToLive) throws JMSException
Typically, a message producer is assigned a destination at creation time; however, the Jakarta Messaging API also supports unidentified message producers, which require that the destination be supplied every time a message is sent.
destination
- the destination to send this message tomessage
- the message to senddeliveryMode
- the delivery mode to usepriority
- the priority for this messagetimeToLive
- the message's lifetime (in milliseconds)JMSException
- if the Jakarta Messaging provider fails to send the message due to some internal error.MessageFormatException
- if an invalid message is specified.InvalidDestinationException
- if a client uses this method with an invalid destination.UnsupportedOperationException
- if a client uses this method with a MessageProducer
that
specified a destination at creation time.Session.createProducer(javax.jms.Destination)
void send(Message message, CompletionListener completionListener) throws JMSException
MessageProducer
's default delivery mode, priority, and time to live, performing
part of the work involved in sending the message in a separate thread and notifying the specified
CompletionListener when the operation has completed. Jakarta Messaging refers to this as an "asynchronous send".
When the message has been successfully sent the Jakarta Messaging provider invokes the callback method onCompletion on an application-specified CompletionListener object. Only when that callback has been invoked can the application be sure that the message has been successfully sent with the same degree of confidence as if a normal synchronous send had been performed. An application which requires this degree of confidence must therefore wait for the callback to be invoked before continuing.
The following information is intended to give an indication of how an asynchronous send would typically be implemented.
In some Jakarta Messaging providers, a normal synchronous send involves sending the message to a remote Jakarta Messaging server and then waiting for an acknowledgement to be received before returning. It is expected that such a provider would implement an asynchronous send by sending the message to the remote Jakarta Messaging server and then returning without waiting for an acknowledgement. When the acknowledgement is received, the Jakarta Messaging provider would notify the application by invoking the onCompletion method on the application-specified CompletionListener object. If for some reason the acknowledgement is not received the Jakarta Messaging provider would notify the application by invoking the CompletionListener's onException method.
In those cases where the Jakarta Messaging specification permits a lower level of reliability, a normal synchronous send might not wait for an acknowledgement. In that case it is expected that an asynchronous send would be similar to a synchronous send: the Jakarta Messaging provider would send the message to the remote Jakarta Messaging server and then return without waiting for an acknowledgement. However the Jakarta Messaging provider would still notify the application that the send had completed by invoking the onCompletion method on the application-specified CompletionListener object.
It is up to the Jakarta Messaging provider to decide exactly what is performed in the calling thread and what, if anything, is performed asynchronously, so long as it satisfies the requirements given below:
Quality of service: After the send operation has completed successfully, which means that the message has been successfully sent with the same degree of confidence as if a normal synchronous send had been performed, the JMS provider must invoke the CompletionListener's onCompletion method. The CompletionListener must not be invoked earlier than this.
Exceptions: If an exception is encountered during the call to the send method then an appropriate exception should be thrown in the thread that is calling the send method. In this case the Jakarta Messaging provider must not invoke the CompletionListener's onCompletion or onException method. If an exception is encountered which cannot be thrown in the thread that is calling the send method then the Jakarta Messaging provider must call the CompletionListener's onException method. In both cases if an exception occurs it is undefined whether or not the message was successfully sent.
Message order: If the same MessageProducer is used to send multiple messages then Jakarta Messaging message ordering requirements must be satisfied. This applies even if a combination of synchronous and asynchronous sends has been performed. The application is not required to wait for an asynchronous send to complete before sending the next message.
Close, commit or rollback: If the close method is called on the MessageProducer or its
Session or Connection then the Jakarta Messaging provider must block until any incomplete send operations have
been completed and all CompletionListener
callbacks have returned before closing the object and returning. If
the session is transacted (uses a local transaction) then when the Session's commit or
rollback method is called the Jakarta Messaging provider must block until any incomplete send operations have been
completed and all CompletionListener
callbacks have returned before performing the commit or rollback.
Incomplete sends should be allowed to complete normally unless an error occurs.
A CompletionListener callback method must not call close on its own Connection, Session or MessageProducer or call commit or rollback on its own Session. Doing so will cause the close, commit or rollback to throw an IllegalStateException.
Restrictions on usage in Jakarta EE This method must not be used in a Jakarta EE EJB or web container. Doing so may
cause a JMSException
to be thrown though this is not guaranteed.
Message headers Jakarta Messaging defines a number of message header fields and message properties which must be set by the "Jakarta Messaging provider on send". If the send is asynchronous these fields and properties may be accessed on the sending client only after the CompletionListener has been invoked. If the CompletionListener's onException method is called then the state of these message header fields and properties is undefined.
Restrictions on threading: Applications that perform an asynchronous send must confirm to the threading restrictions defined in JMS. This means that the session may be used by only one thread at a time.
Setting a CompletionListener does not cause the session to be dedicated to the thread of control which calls the CompletionListener. The application thread may therefore continue to use the session after performing an asynchronous send. However the CompletionListener's callback methods must not use the session if an application thread might be using the session at the same time.
Use of the CompletionListener by the Jakarta Messaging provider: A session will only invoke one
CompletionListener callback method at a time. For a given MessageProducer, callbacks (both
onCompletion
and onException
) will be performed in the same order as the corresponding calls to the
asynchronous send method. A Jakarta Messaging provider must not invoke the CompletionListener from the thread that is
calling the asynchronous send method.
Restrictions on the use of the Message object: Applications which perform an asynchronous send must take account of the restriction that a Message object is designed to be accessed by one logical thread of control at a time and does not support concurrent use.
After the send method has returned, the application must not attempt to read the headers, properties or body of the Message object until the CompletionListener's onCompletion or onException method has been called. This is because the Jakarta Messaging provider may be modifying the Message object in another thread during this time. The Jakarta Messaging provider may throw an JMSException if the application attempts to access or modify the Message object after the send method has returned and before the CompletionListener has been invoked. If the Jakarta Messaging provider does not throw an exception then the behaviour is undefined.
message
- the message to sendcompletionListener
- a CompletionListener
to be notified when the send has completedJMSException
- if an internal error occursMessageFormatException
- if an invalid message is specified.InvalidDestinationException
- if a client uses this method with a MessageProducer
with an invalid
destination.IllegalArgumentException
- if the specified CompletionListener
is nullUnsupportedOperationException
- if a client uses this method with a MessageProducer
that
did not specify a destination at creation time.Session.createProducer(javax.jms.Destination)
,
CompletionListener
void send(Message message, int deliveryMode, int priority, long timeToLive, CompletionListener completionListener) throws JMSException
When the message has been successfully sent the Jakarta Messaging provider invokes the callback method onCompletion on an application-specified CompletionListener object. Only when that callback has been invoked can the application be sure that the message has been successfully sent with the same degree of confidence as if a normal synchronous send had been performed. An application which requires this degree of confidence must therefore wait for the callback to be invoked before continuing.
The following information is intended to give an indication of how an asynchronous send would typically be implemented.
In some Jakarta Messaging providers, a normal synchronous send involves sending the message to a remote Jakarta Messaging server and then waiting for an acknowledgement to be received before returning. It is expected that such a provider would implement an asynchronous send by sending the message to the remote Jakarta Messaging server and then returning without waiting for an acknowledgement. When the acknowledgement is received, the Jakarta Messaging provider would notify the application by invoking the onCompletion method on the application-specified CompletionListener object. If for some reason the acknowledgement is not received the Jakarta Messaging provider would notify the application by invoking the CompletionListener's onException method.
In those cases where the Jakarta Messaging specification permits a lower level of reliability, a normal synchronous send might not wait for an acknowledgement. In that case it is expected that an asynchronous send would be similar to a synchronous send: the Jakarta Messaging provider would send the message to the remote Jakarta Messaging server and then return without waiting for an acknowledgement. However the Jakarta Messaging provider would still notify the application that the send had completed by invoking the onCompletion method on the application-specified CompletionListener object.
It is up to the Jakarta Messaging provider to decide exactly what is performed in the calling thread and what, if anything, is performed asynchronously, so long as it satisfies the requirements given below:
Quality of service: After the send operation has completed successfully, which means that the message has been successfully sent with the same degree of confidence as if a normal synchronous send had been performed, the JMS provider must invoke the CompletionListener's onCompletion method. The CompletionListener must not be invoked earlier than this.
Exceptions: If an exception is encountered during the call to the send method then an appropriate exception should be thrown in the thread that is calling the send method. In this case the Jakarta Messaging provider must not invoke the CompletionListener's onCompletion or onException method. If an exception is encountered which cannot be thrown in the thread that is calling the send method then the Jakarta Messaging provider must call the CompletionListener's onException method. In both cases if an exception occurs it is undefined whether or not the message was successfully sent.
Message order: If the same MessageProducer is used to send multiple messages then Jakarta Messaging message ordering requirements must be satisfied. This applies even if a combination of synchronous and asynchronous sends has been performed. The application is not required to wait for an asynchronous send to complete before sending the next message.
Close, commit or rollback: If the close method is called on the MessageProducer or its
Session or Connection then the Jakarta Messaging provider must block until any incomplete send operations have
been completed and all CompletionListener
callbacks have returned before closing the object and returning. If
the session is transacted (uses a local transaction) then when the Session's commit or
rollback method is called the Jakarta Messaging provider must block until any incomplete send operations have been
completed and all CompletionListener
callbacks have returned before performing the commit or rollback.
Incomplete sends should be allowed to complete normally unless an error occurs.
A CompletionListener callback method must not call close on its own Connection, Session or MessageProducer or call commit or rollback on its own Session. Doing so will cause the close, commit or rollback to throw an IllegalStateException.
Restrictions on usage in Jakarta EE This method must not be used in a Jakarta EE EJB or web container. Doing so may
cause a JMSException
to be thrown though this is not guaranteed.
Message headers Jakarta Messaging defines a number of message header fields and message properties which must be set by the "Jakarta Messaging provider on send". If the send is asynchronous these fields and properties may be accessed on the sending client only after the CompletionListener has been invoked. If the CompletionListener's onException method is called then the state of these message header fields and properties is undefined.
Restrictions on threading: Applications that perform an asynchronous send must confirm to the threading restrictions defined in JMS. This means that the session may be used by only one thread at a time.
Setting a CompletionListener does not cause the session to be dedicated to the thread of control which calls the CompletionListener. The application thread may therefore continue to use the session after performing an asynchronous send. However the CompletionListener's callback methods must not use the session if an application thread might be using the session at the same time.
Use of the CompletionListener by the Jakarta Messaging provider: A session will only invoke one
CompletionListener callback method at a time. For a given MessageProducer, callbacks (both
onCompletion
and onException
) will be performed in the same order as the corresponding calls to the
asynchronous send method. A Jakarta Messaging provider must not invoke the CompletionListener from the thread that is
calling the asynchronous send method.
Restrictions on the use of the Message object: Applications which perform an asynchronous send must take account of the restriction that a Message object is designed to be accessed by one logical thread of control at a time and does not support concurrent use.
After the send method has returned, the application must not attempt to read the headers, properties or body of the Message object until the CompletionListener's onCompletion or onException method has been called. This is because the Jakarta Messaging provider may be modifying the Message object in another thread during this time. The Jakarta Messaging provider may throw an JMSException if the application attempts to access or modify the Message object after the send method has returned and before the CompletionListener has been invoked. If the Jakarta Messaging provider does not throw an exception then the behaviour is undefined.
message
- the message to senddeliveryMode
- the delivery mode to usepriority
- the priority for this messagetimeToLive
- the message's lifetime (in milliseconds)completionListener
- a CompletionListener
to be notified when the send has completedJMSException
- if an internal error occursMessageFormatException
- if an invalid message is specified.InvalidDestinationException
- if a client uses this method with a MessageProducer
with an invalid
destination.IllegalArgumentException
- if the specified CompletionListener
is nullUnsupportedOperationException
- if a client uses this method with a MessageProducer
that
did not specify a destination at creation time.Session.createProducer(javax.jms.Destination)
,
CompletionListener
void send(Destination destination, Message message, CompletionListener completionListener) throws JMSException
MessageProducer
's default
delivery mode, priority, and time to live, performing part of the work involved in sending the message in a separate
thread and notifying the specified CompletionListener when the operation has completed. Jakarta Messaging refers to this
as an "asynchronous send".
Typically, a message producer is assigned a destination at creation time; however, the Jakarta Messaging API also supports unidentified message producers, which require that the destination be supplied every time a message is sent.
When the message has been successfully sent the Jakarta Messaging provider invokes the callback method onCompletion on an application-specified CompletionListener object. Only when that callback has been invoked can the application be sure that the message has been successfully sent with the same degree of confidence as if a normal synchronous send had been performed. An application which requires this degree of confidence must therefore wait for the callback to be invoked before continuing.
The following information is intended to give an indication of how an asynchronous send would typically be implemented.
In some Jakarta Messaging providers, a normal synchronous send involves sending the message to a remote Jakarta Messaging server and then waiting for an acknowledgement to be received before returning. It is expected that such a provider would implement an asynchronous send by sending the message to the remote Jakarta Messaging server and then returning without waiting for an acknowledgement. When the acknowledgement is received, the Jakarta Messaging provider would notify the application by invoking the onCompletion method on the application-specified CompletionListener object. If for some reason the acknowledgement is not received the Jakarta Messaging provider would notify the application by invoking the CompletionListener's onException method.
In those cases where the Jakarta Messaging specification permits a lower level of reliability, a normal synchronous send might not wait for an acknowledgement. In that case it is expected that an asynchronous send would be similar to a synchronous send: the Jakarta Messaging provider would send the message to the remote Jakarta Messaging server and then return without waiting for an acknowledgement. However the Jakarta Messaging provider would still notify the application that the send had completed by invoking the onCompletion method on the application-specified CompletionListener object.
It is up to the Jakarta Messaging provider to decide exactly what is performed in the calling thread and what, if anything, is performed asynchronously, so long as it satisfies the requirements given below:
Quality of service: After the send operation has completed successfully, which means that the message has been successfully sent with the same degree of confidence as if a normal synchronous send had been performed, the JMS provider must invoke the CompletionListener's onCompletion method. The CompletionListener must not be invoked earlier than this.
Exceptions: If an exception is encountered during the call to the send method then an appropriate exception should be thrown in the thread that is calling the send method. In this case the Jakarta Messaging provider must not invoke the CompletionListener's onCompletion or onException method. If an exception is encountered which cannot be thrown in the thread that is calling the send method then the Jakarta Messaging provider must call the CompletionListener's onException method. In both cases if an exception occurs it is undefined whether or not the message was successfully sent.
Message order: If the same MessageProducer is used to send multiple messages then Jakarta Messaging message ordering requirements must be satisfied. This applies even if a combination of synchronous and asynchronous sends has been performed. The application is not required to wait for an asynchronous send to complete before sending the next message.
Close, commit or rollback: If the close method is called on the MessageProducer or its
Session or Connection then the Jakarta Messaging provider must block until any incomplete send operations have
been completed and all CompletionListener
callbacks have returned before closing the object and returning. If
the session is transacted (uses a local transaction) then when the Session's commit or
rollback method is called the Jakarta Messaging provider must block until any incomplete send operations have been
completed and all CompletionListener
callbacks have returned before performing the commit or rollback.
Incomplete sends should be allowed to complete normally unless an error occurs.
A CompletionListener callback method must not call close on its own Connection, Session or MessageProducer or call commit or rollback on its own Session. Doing so will cause the close, commit or rollback to throw an IllegalStateException.
Restrictions on usage in Jakarta EE This method must not be used in a Jakarta EE EJB or web container. Doing so may
cause a JMSException
to be thrown though this is not guaranteed.
Message headers Jakarta Messaging defines a number of message header fields and message properties which must be set by the "Jakarta Messaging provider on send". If the send is asynchronous these fields and properties may be accessed on the sending client only after the CompletionListener has been invoked. If the CompletionListener's onException method is called then the state of these message header fields and properties is undefined.
Restrictions on threading: Applications that perform an asynchronous send must confirm to the threading restrictions defined in JMS. This means that the session may be used by only one thread at a time.
Setting a CompletionListener does not cause the session to be dedicated to the thread of control which calls the CompletionListener. The application thread may therefore continue to use the session after performing an asynchronous send. However the CompletionListener's callback methods must not use the session if an application thread might be using the session at the same time.
Use of the CompletionListener by the Jakarta Messaging provider: A session will only invoke one
CompletionListener callback method at a time. For a given MessageProducer, callbacks (both
onCompletion
and onException
) will be performed in the same order as the corresponding calls to the
asynchronous send method. A Jakarta Messaging provider must not invoke the CompletionListener from the thread that is
calling the asynchronous send method.
Restrictions on the use of the Message object: Applications which perform an asynchronous send must take account of the restriction that a Message object is designed to be accessed by one logical thread of control at a time and does not support concurrent use.
After the send method has returned, the application must not attempt to read the headers, properties or body of the Message object until the CompletionListener's onCompletion or onException method has been called. This is because the Jakarta Messaging provider may be modifying the Message object in another thread during this time. The Jakarta Messaging provider may throw an JMSException if the application attempts to access or modify the Message object after the send method has returned and before the CompletionListener has been invoked. If the Jakarta Messaging provider does not throw an exception then the behaviour is undefined.
destination
- the destination to send this message tomessage
- the message to sendcompletionListener
- a CompletionListener
to be notified when the send has completedJMSException
- if an internal error occursMessageFormatException
- if an invalid message is specified.InvalidDestinationException
- if a client uses this method with an invalid destinationIllegalArgumentException
- if the specified CompletionListener
is nullUnsupportedOperationException
- if a client uses this method with a MessageProducer
that
specified a destination at creation time.Session.createProducer(javax.jms.Destination)
,
CompletionListener
void send(Destination destination, Message message, int deliveryMode, int priority, long timeToLive, CompletionListener completionListener) throws JMSException
Typically, a message producer is assigned a destination at creation time; however, the Jakarta Messaging API also supports unidentified message producers, which require that the destination be supplied every time a message is sent.
When the message has been successfully sent the Jakarta Messaging provider invokes the callback method onCompletion on an application-specified CompletionListener object. Only when that callback has been invoked can the application be sure that the message has been successfully sent with the same degree of confidence as if a normal synchronous send had been performed. An application which requires this degree of confidence must therefore wait for the callback to be invoked before continuing.
The following information is intended to give an indication of how an asynchronous send would typically be implemented.
In some Jakarta Messaging providers, a normal synchronous send involves sending the message to a remote Jakarta Messaging server and then waiting for an acknowledgement to be received before returning. It is expected that such a provider would implement an asynchronous send by sending the message to the remote Jakarta Messaging server and then returning without waiting for an acknowledgement. When the acknowledgement is received, the Jakarta Messaging provider would notify the application by invoking the onCompletion method on the application-specified CompletionListener object. If for some reason the acknowledgement is not received the Jakarta Messaging provider would notify the application by invoking the CompletionListener's onException method.
In those cases where the Jakarta Messaging specification permits a lower level of reliability, a normal synchronous send might not wait for an acknowledgement. In that case it is expected that an asynchronous send would be similar to a synchronous send: the Jakarta Messaging provider would send the message to the remote Jakarta Messaging server and then return without waiting for an acknowledgement. However the Jakarta Messaging provider would still notify the application that the send had completed by invoking the onCompletion method on the application-specified CompletionListener object.
It is up to the Jakarta Messaging provider to decide exactly what is performed in the calling thread and what, if anything, is performed asynchronously, so long as it satisfies the requirements given below:
Quality of service: After the send operation has completed successfully, which means that the message has been successfully sent with the same degree of confidence as if a normal synchronous send had been performed, the JMS provider must invoke the CompletionListener's onCompletion method. The CompletionListener must not be invoked earlier than this.
Exceptions: If an exception is encountered during the call to the send method then an appropriate exception should be thrown in the thread that is calling the send method. In this case the Jakarta Messaging provider must not invoke the CompletionListener's onCompletion or onException method. If an exception is encountered which cannot be thrown in the thread that is calling the send method then the Jakarta Messaging provider must call the CompletionListener's onException method. In both cases if an exception occurs it is undefined whether or not the message was successfully sent.
Message order: If the same MessageProducer is used to send multiple messages then Jakarta Messaging message ordering requirements must be satisfied. This applies even if a combination of synchronous and asynchronous sends has been performed. The application is not required to wait for an asynchronous send to complete before sending the next message.
Close, commit or rollback: If the close method is called on the MessageProducer or its
Session or Connection then the Jakarta Messaging provider must block until any incomplete send operations have
been completed and all CompletionListener
callbacks have returned before closing the object and returning. If
the session is transacted (uses a local transaction) then when the Session's commit or
rollback method is called the Jakarta Messaging provider must block until any incomplete send operations have been
completed and all CompletionListener
callbacks have returned before performing the commit or rollback.
Incomplete sends should be allowed to complete normally unless an error occurs.
A CompletionListener callback method must not call close on its own Connection, Session or MessageProducer or call commit or rollback on its own Session. Doing so will cause the close, commit or rollback to throw an IllegalStateException.
Restrictions on usage in Jakarta EE This method must not be used in a Jakarta EE EJB or web container. Doing so may
cause a JMSException
to be thrown though this is not guaranteed.
Message headers Jakarta Messaging defines a number of message header fields and message properties which must be set by the "Jakarta Messaging provider on send". If the send is asynchronous these fields and properties may be accessed on the sending client only after the CompletionListener has been invoked. If the CompletionListener's onException method is called then the state of these message header fields and properties is undefined.
Restrictions on threading: Applications that perform an asynchronous send must confirm to the threading restrictions defined in JMS. This means that the session may be used by only one thread at a time.
Setting a CompletionListener does not cause the session to be dedicated to the thread of control which calls the CompletionListener. The application thread may therefore continue to use the session after performing an asynchronous send. However the CompletionListener's callback methods must not use the session if an application thread might be using the session at the same time.
Use of the CompletionListener by the Jakarta Messaging provider: A session will only invoke one
CompletionListener callback method at a time. For a given MessageProducer, callbacks (both
onCompletion
and onException
) will be performed in the same order as the corresponding calls to the
asynchronous send method. A Jakarta Messaging provider must not invoke the CompletionListener from the thread that is
calling the asynchronous send method.
Restrictions on the use of the Message object: Applications which perform an asynchronous send must take account of the restriction that a Message object is designed to be accessed by one logical thread of control at a time and does not support concurrent use.
After the send method has returned, the application must not attempt to read the headers, properties or body of the Message object until the CompletionListener's onCompletion or onException method has been called. This is because the Jakarta Messaging provider may be modifying the Message object in another thread during this time. The Jakarta Messaging provider may throw an JMSException if the application attempts to access or modify the Message object after the send method has returned and before the CompletionListener has been invoked. If the Jakarta Messaging provider does not throw an exception then the behaviour is undefined.
destination
- the destination to send this message tomessage
- the message to senddeliveryMode
- the delivery mode to usepriority
- the priority for this messagetimeToLive
- the message's lifetime (in milliseconds)completionListener
- a CompletionListener
to be notified when the send has completedJMSException
- if an internal error occursMessageFormatException
- if an invalid message is specified.InvalidDestinationException
- if a client uses this method with an invalid destination.IllegalArgumentException
- if the specified CompletionListener
is nullUnsupportedOperationException
- if a client uses this method with a MessageProducer
that
specified a destination at creation time.Session.createProducer(javax.jms.Destination)
,
CompletionListener
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