Package jakarta.jms
The Jakarta Messaging API provides a common way for Java programs to create, send, receive and read an enterprise messaging system's messages.
Jakarta Messaging Applications
A Jakarta Messaging application is composed of the following parts:
- Jakarta Messaging provider - a messaging system that implements the Jakarta Messaging API in addition to the other administrative and control functionality required of a full-featured messaging product
- Jakarta Messaging clients - the Java language programs that send and receive messages
- Messages - objects that are used to communicate information between the clients of an application
- Administered objects - provider-specific objects that clients look up and use to interact portably with a Jakarta Messaging provider
- Non-Jakarta Messaging clients - clients that use a message system's native client API instead of the Jakarta Messaging API. If the application predated the availability of the Jakarta Messaging API, it is likely that it will include both Jakarta Messaging clients and non-Jakarta Messaging clients.
Administration
Jakarta Messaging providers differ significantly in their implementations of underlying messaging technology. There are also major differences in how a Jakarta Messaging provider's system is installed and administered.
For Jakarta Messaging clients to be portable, they must be isolated from these proprietary aspects of a provider. This is done by defining Jakarta Messaging administered objects that are created and customised by a provider's administrator and later used by clients. The client uses them through Jakarta Messaging interfaces that are portable. The administrator creates them using provider-specific facilities.
There are two types of Jakarta Messaging administered objects:
ConnectionFactory- the object a client uses to create a connection with a Jakarta Messaging providerDestination- the object a client uses to specify the destination of messages it is sending and the source of messages it receives
Administered objects are placed by an administrator in a JNDI (Java Naming and Directory Interface) namespace. A Jakarta Messaging client typically notes in its documentation the Jakarta Messaging administered objects it requires and how the JNDI names of these objects should be provided to it.
Two Messaging Styles
Jakarta Messaging supports two styles of messaging:
- point-to-point (PTP) messaging using queues
- publish-and-subscribe (pub/sub)messaging using topics
These two styles represent two of the dominant approaches to messaging currently in use.
Jakarta Messaging APIs
For historical reasons Jakarta Messaging offers four alternative sets of interfaces for sending and receiving messages:
- Java Message Service 1.0 defined two domain-specific APIs, one for point-to-point messaging (queues) and one for pub/sub (topics). Although these remain part of Jakarta Messaging for reasons of backwards compatibility they should be considered to be completely superseded by the later APIs.
- Java Message Service 1.1 introduced a new unified API which offered a single set of interfaces that could be used for both point-to-point and pub/sub messaging. This is referred to here as the classic API.
- Jakarta Messaging 2.0 introduces a simplified API which offers all the features of the classic API but which requires fewer interfaces and is simpler to use.
Each API offers a different set of interfaces for connecting to a Jakarta Messaging provider and for sending and receiving messages. However they all share a common set of interfaces for representing messages and message destinations and to provide various utility features.
All interfaces are in the jakarta.jms package.
Interfaces common to multiple APIs
The main interfaces common to multiple APIs are as follows:
Message,BytesMessage,MapMessage,ObjectMessage,StreamMessageandTextMessage- a message sent to or received from a Jakarta Messaging provider.Queue- an administered object that encapsulates the identity of a message destination for point-to-point messagingTopic- an administered object that encapsulates the identity of a message destination for pub/sub messaging.Destination- the common supertype ofQueueandTopic
Classic API interfaces
The main interfaces provided by the classic API are as follows:ConnectionFactory- an administered object used by a client to create aConnection. This interface is also used by the simplified API.Connection- an active connection to a Jakarta Messaging providerSession- a single-threaded context for sending and receiving messagesMessageProducer- an object created by a Session that is used for sending messages to a queue or topicMessageConsumer- an object created by a Session that is used for receiving messages sent to a queue or topic
Simplified API interfaces
The simplified API provides the same messaging functionality as the classic API but requires fewer interfaces and is simpler to use. The main interfaces provided by the simplified API are as follows:ConnectionFactory- an administered object used by a client to create aJMSContext. This interface is also used by the classic API.JMSContext- an active connection to a Jakarta Messaging provider and a single-threaded context for sending and receiving messagesJMSProducer- an object created by aJMSContextthat is used for sending messages to a queue or topicJMSConsumer- an object created by aJMSContextthat is used for receiving messages sent to a queue or topic
Legacy domain-specific API interfaces
Although the domain-specific API remains part of Jakarta Messaging for reasons of backwards compatibility it should be considered to be completely superseded by the classic and simplified APIs.
The main interfaces provided by the domain-specific API for point-to-point messaging are as follows:
QueueConnectionFactory- an administered object used by a client to create aQueueConnection.QueueConnection- an active connection to a Jakarta Messaging providerQueueSession- a single-threaded context for sending and receiving messagesQueueSender- an object created by aQueueSessionthat is used for sending messages to a queueQueueReceiver- an object created by aQueueSessionthat is used for receiving messages sent to a queue
TopicConnectionFactory- an administered object used by a client to create aTopicConnection.TopicConnection- an active connection to a Jakarta Messaging providerTopicSession- a single-threaded context for sending and receiving messagesTopicPublisher- an object created by aTopicSessionthat is used for sending messages to a topicTopicSubscriber- an object created by aTopicSessionthat is used for receiving messages sent to a topic
Terminology for sending and receiving messages
The term consume is used in this document to mean the receipt of a message by a Jakarta Messaging client; that is, a Jakarta Messaging provider has received a message and has given it to its client. Since Jakarta Messaging supports both synchronous and asynchronous receipt of messages, the term consume is used when there is no need to make a distinction between them.
The term produce is used as the most general term for sending a message. It means giving a message to a Jakarta Messaging provider for delivery to a destination.
Developing a Jakarta Messaging Application
Broadly speaking, a Jakarta Messaging application is one or more Jakarta Messaging clients that exchange messages. The application may also involve non-Jakarta Messaging clients; however, these clients use the Jakarta Messaging provider's native API in place of the Jakarta Messaging API.
A Jakarta Messaging application can be architected and deployed as a unit. In many cases, Jakarta Messaging clients are added incrementally to an existing application.
The message definitions used by an application may originate with JMS, or they may have been defined by the non-Jakarta Messaging part of the application.
Developing a Jakarta Messaging Client
A typical Jakarta Messaging client using the classic API executes the following Jakarta Messaging setup procedure:
- Use JNDI to find a
ConnectionFactoryobject - Use JNDI to find one or more
Destinationobjects - Use the ConnectionFactory to create a Jakarta Messaging
Connectionobject with message delivery inhibited - Use the Connection to create one or more Jakarta Messaging
Sessionobjects - Use a Session and the Destinations to create the
MessageProducerandMessageConsumerobjects needed - Tell the
Connectionto start delivery of messages
In contrast, a typical Jakarta Messaging client using the simplified API does the following:
- Use JNDI to find a
ConnectionFactoryobject - Use JNDI to find one or more
Destinationobjects - Use the
ConnectionFactoryto create aJMSContextobject - Use the
JMSContextto create theJMSProducerandJMSConsumerobjects needed. - Delivery of message is started automatically
At this point a client has the basic Jakarta Messaging setup needed to produce and consume messages.
Package Specification
Jakarta Messaging 2.0 specification
Related Documentation
Jakarta Enterprise Edition Technical Documentation
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ClassDescriptionA
BytesMessageobject is used to send a message containing a stream of uninterpreted bytes.ACompletionListeneris implemented by the application and may be specified when a message is sent asynchronously.AConnectionobject is a client's active connection to its Jakarta Messaging provider.For application servers,Connectionobjects provide a special facility for creating aConnectionConsumer(optional).AConnectionFactoryobject encapsulates a set of connection configuration parameters that has been defined by an administrator.AConnectionMetaDataobject provides information describing theConnectionobject.The delivery modes supported by the Jakarta Messaging API arePERSISTENTandNON_PERSISTENT.ADestinationobject encapsulates a provider-specific address.If a Jakarta Messaging provider detects a serious problem with aConnectionobject, it informs theConnectionobject'sExceptionListener, if one has been registered.This exception is thrown when a method is invoked at an illegal or inappropriate time or if the provider is not in an appropriate state for the requested operation.This unchecked exception is thrown when a method is invoked at an illegal or inappropriate time or if the provider is not in an appropriate state for the requested operation, and the method signature does not permit aIllegalStateRuntimeExceptionto be thrown.This exception must be thrown when a client attempts to set a connection's client ID to a value that is rejected by a provider.This unchecked exception must be thrown when a client attempts to set a connection's client ID to a value that is rejected by a provider, and the method signature does not permit aInvalidClientIDExceptionto be thrown.This exception must be thrown when a destination either is not understood by a provider or is no longer valid.This unchecked exception must be thrown when a destination either is not understood by a provider or is no longer valid, and the method signature does not permit aInvalidDestinationExceptionto be thrown.This exception must be thrown when a Jakarta Messaging client attempts to give a provider a message selector with invalid syntax.This unchecked exception must be thrown when a Jakarta Messaging client attempts to give a provider a message selector with invalid syntax, and the method signature does not permit aInvalidSelectorExceptionto be thrown.This annotation may be used on a field to specify the JNDI lookup name of ajakarta.jms.ConnectionFactoryto be used when injecting ajakarta.jms.JMSContextobject.An application may use this annotation to specify a Jakarta MessagingConnectionFactoryresource that it requires in its operational environment.Specifies one or moreJMSConnectionFactoryDefinitionannotations.A client using the simplified Jakarta Messaging API introduced for Jakarta Messaging 2.0 uses aJMSConsumerobject to receive messages from a queue or topic.AJMSContextis the main interface in the simplified Jakarta Messaging API introduced for Jakarta Messaging 2.0.An application may use this annotation to specify a Jakarta MessagingDestinationresource that it requires in its operational environment.Specifies one or moreJMSDestinationDefinitionannotations.This is the root class of all checked exceptions in the Jakarta Messaging API.This annotation may be used to specify the userName and password to be used when injecting ajakarta.jms.JMSContextobject.AJMSProduceris a simple object used to send messages on behalf of aJMSContext.This is the root class of all unchecked exceptions in the Jakarta Messaging API.This exception must be thrown when a provider rejects a user name/password submitted by a client.This unchecked exception must be thrown when a provider rejects a user name/password submitted by a client, or for any case where a security restriction prevents a method from completing, and the method signature does not permit aJMSSecurityExceptionto be thrown.This annotation may be used to specify the session mode to be used when injecting ajakarta.jms.JMSContextobject.AMapMessageobject is used to send a set of name-value pairs.TheMessageinterface is the root interface of all Jakarta Messaging messages.A client uses aMessageConsumerobject to receive messages from a destination.This exception must be thrown when an unexpected end of stream has been reached when aStreamMessageorBytesMessageis being read.This exception must be thrown when a Jakarta Messaging client attempts to use a data type not supported by a message or attempts to read data in a message as the wrong type.This unchecked exception must be thrown when a Jakarta Messaging application attempts to use a data type not supported by a message or attempts to read data in a message as the wrong type, and the method signature does not permit aMessageFormatExceptionto be thrown.AMessageListenerobject is used to receive asynchronously delivered messages.This exception must be thrown when a Jakarta Messaging client attempts to read a write-only message.This exception must be thrown when a Jakarta Messaging client attempts to write to a read-only message.This unchecked exception must be thrown when a Jakarta Messaging client attempts to write to a read-only message.A client uses aMessageProducerobject to send messages to a destination.AnObjectMessageobject is used to send a message that contains a serializable object in the Java programming language ("Java object").AQueueobject encapsulates a provider-specific queue name.A client uses aQueueBrowserobject to look at messages on a queue without removing them.AQueueConnectionobject is an active connection to a point-to-point Jakarta Messaging provider.A client uses aQueueConnectionFactoryobject to createQueueConnectionobjects with a point-to-point Jakarta Messaging provider.A client uses aQueueReceiverobject to receive messages that have been delivered to a queue.TheQueueRequestorhelper class simplifies making service requests.A client uses aQueueSenderobject to send messages to a queue.AQueueSessionobject provides methods for creatingQueueReceiver,QueueSender,QueueBrowser, andTemporaryQueueobjects.This exception is thrown when a provider is unable to allocate the resources required by a method.This unchecked exception is thrown when a provider is unable to allocate the resources required by a method.AServerSessionobject is an application server object that is used by a server to associate a thread with a Jakarta Messaging session (optional).AServerSessionPoolobject is an object implemented by an application server to provide a pool ofServerSessionobjects for processing the messages of aConnectionConsumer(optional).ASessionobject is a single-threaded context for producing and consuming messages.AStreamMessageobject is used to send a stream of primitive types in the Java programming language.ATemporaryQueueobject is a uniqueQueueobject created for the duration of aConnection.ATemporaryTopicobject is a uniqueTopicobject created for the duration of aConnection.ATextMessageobject is used to send a message containing ajava.lang.String.ATopicobject encapsulates a provider-specific topic name.ATopicConnectionobject is an active connection to a publish/subscribe Jakarta Messaging provider.A client uses aTopicConnectionFactoryobject to createTopicConnectionobjects with a publish/subscribe Jakarta Messaging provider.A client uses aTopicPublisherobject to publish messages on a topic.TheTopicRequestorhelper class simplifies making service requests.ATopicSessionobject provides methods for creatingTopicPublisher,TopicSubscriber, andTemporaryTopicobjects.A client uses aTopicSubscriberobject to receive messages that have been published to a topic.This exception is thrown when an operation is invalid because a transaction is in progress.This unchecked exception is thrown when an operation is invalid because a transaction is in progress.This exception must be thrown when a call toSession.commitresults in a rollback of the current transaction.This unchecked exception must be thrown when a call toJMSContext.commitresults in a rollback of the current transaction.TheXAConnectioninterface extends the capability ofConnectionby providing anXASession(optional).TheXAConnectionFactoryinterface is a base interface for theXAQueueConnectionFactoryandXATopicConnectionFactoryinterfaces.TheXAJMSContextinterface extends the capability ofJMSContextby adding access to a Jakarta Messaging provider's support for the Java Transaction API (JTA) (optional).AnXAQueueConnectionprovides the same create options asQueueConnection(optional).AnXAQueueConnectionFactoryprovides the same create options as aQueueConnectionFactory(optional).AnXAQueueSessionprovides a regularQueueSession, which can be used to createQueueReceiver,QueueSender, andQueueBrowserobjects (optional).TheXASessioninterface extends the capability ofSessionby adding access to a Jakarta Messaging provider's support for the Java Transaction API (JTA) (optional).AnXATopicConnectionprovides the same create options asTopicConnection(optional).AnXATopicConnectionFactoryprovides the same create options as aTopicConnectionFactory(optional).AnXATopicSessionprovides a regularTopicSession.