Package javax.jms

package javax.jms

The Java Message Service (JMS) API provides a common way for Java programs to create, send, receive and read an enterprise messaging system's messages.

JMS Applications

A JMS application is composed of the following parts:

• JMS provider - a messaging system that implements the JMS API in addition to the other administrative and control functionality required of a full-featured messaging product
• JMS 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 JMS provider
• Non-JMS clients - clients that use a message system's native client API instead of the JMS API. If the application predated the availability of the JMS API, it is likely that it will include both JMS clients and non-JMS clients.

Administration

JMS providers differ significantly in their implementations of underlying messaging technology. There are also major differences in how a JMS provider's system is installed and administered.

For JMS clients to be portable, they must be isolated from these proprietary aspects of a provider. This is done by defining JMS administered objects that are created and customised by a provider's administrator and later used by clients. The client uses them through JMS interfaces that are portable. The administrator creates them using provider-specific facilities.

There are two types of JMS administered objects:

• ConnectionFactory - the object a client uses to create a connection with a JMS provider
• Destination - 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 JMS client typically notes in its documentation the JMS administered objects it requires and how the JNDI names of these objects should be provided to it.

Two Messaging Styles

JMS 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.

JMS APIs

For historical reasons JMS offers four alternative sets of interfaces for sending and receiving messages:

• JMS 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 JMS for reasons of backwards compatibility they should be considered to be completely superseded by the later APIs.
• JMS 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.
• JMS 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 JMS 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 javax.jms package.

Interfaces common to multiple APIs

The main interfaces common to multiple APIs are as follows:

• Message, BytesMessage, MapMessage, ObjectMessage, StreamMessage and TextMessage - a message sent to or received from a JMS provider.
• Queue - an administered object that encapsulates the identity of a message destination for point-to-point messaging
• Topic - an administered object that encapsulates the identity of a message destination for pub/sub messaging.
• Destination - the common supertype of Queue and Topic

Classic API interfaces

The main interfaces provided by the classic API are as follows:

• ConnectionFactory - an administered object used by a client to create a Connection. This interface is also used by the simplified API.
• Connection - an active connection to a JMS provider
• Session - a single-threaded context for sending and receiving messages
• MessageProducer - an object created by a Session that is used for sending messages to a queue or topic
• MessageConsumer - 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 a JMSContext. This interface is also used by the classic API.
• JMSContext - an active connection to a JMS provider and a single-threaded context for sending and receiving messages
• JMSProducer - an object created by a JMSContext that is used for sending messages to a queue or topic
• JMSConsumer - an object created by a JMSContext that is used for receiving messages sent to a queue or topic

Legacy domain-specific API interfaces

Although the domain-specific API remains part of JMS 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 a QueueConnection.
• QueueConnection - an active connection to a JMS provider
• QueueSession - a single-threaded context for sending and receiving messages
• QueueSender - an object created by a QueueSession that is used for sending messages to a queue
• QueueReceiver - an object created by a QueueSession that is used for receiving messages sent to a queue

The main interfaces provided by the domain-specific API for pub/sub messaging are as follows:

• TopicConnectionFactory - an administered object used by a client to create a TopicConnection.
• TopicConnection - an active connection to a JMS provider
• TopicSession - a single-threaded context for sending and receiving messages
• TopicPublisher - an object created by a TopicSession that is used for sending messages to a topic
• TopicSubscriber - an object created by a TopicSession that 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 JMS client; that is, a JMS provider has received a message and has given it to its client. Since JMS 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 JMS provider for delivery to a destination.

Developing a JMS Application

Broadly speaking, a JMS application is one or more JMS clients that exchange messages. The application may also involve non-JMS clients; however, these clients use the JMS provider's native API in place of the JMS API.

A JMS application can be architected and deployed as a unit. In many cases, JMS 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-JMS part of the application.

Developing a JMS Client

A typical JMS client using the classic API executes the following JMS setup procedure:

• Use JNDI to find a ConnectionFactory object
• Use JNDI to find one or more Destination objects
• Use the ConnectionFactory to create a JMS Connection object with message delivery inhibited
• Use the Connection to create one or more JMS Session objects
• Use a Session and the Destinations to create the MessageProducer and MessageConsumer objects needed
• Tell the Connection to start delivery of messages

In contrast, a typical JMS client using the simplified API does the following:

• Use JNDI to find a ConnectionFactory object
• Use JNDI to find one or more Destination objects
• Use the ConnectionFactory to create a JMSContext object
• Use the JMSContext to create the JMSProducer and JMSConsumer objects needed.
• Delivery of message is started automatically

At this point a client has the basic JMS setup needed to produce and consume messages.

Package Specification

Java Message Service 2.0 specification

Related Documentation

Java Platform, Enterprise Edition (Java EE) Technical Documentation

Class	Description
BytesMessage	A BytesMessage object is used to send a message containing a stream of uninterpreted bytes.
CompletionListener	A CompletionListener is implemented by the application and may be specified when a message is sent asynchronously.
Connection	A Connection object is a client's active connection to its JMS provider.
ConnectionConsumer	For application servers, Connection objects provide a special facility for creating a ConnectionConsumer (optional).
ConnectionFactory	A ConnectionFactory object encapsulates a set of connection configuration parameters that has been defined by an administrator.
ConnectionMetaData	A ConnectionMetaData object provides information describing the Connection object.
DeliveryMode	The delivery modes supported by the JMS API are PERSISTENT and NON_PERSISTENT.
Destination	A Destination object encapsulates a provider-specific address.
ExceptionListener	If a JMS provider detects a serious problem with a Connection object, it informs the Connection object's ExceptionListener, if one has been registered.
IllegalStateException	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.
IllegalStateRuntimeException	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 a IllegalStateRuntimeException to be thrown.
InvalidClientIDException	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.
InvalidClientIDRuntimeException	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 a InvalidClientIDException to be thrown.
InvalidDestinationException	This exception must be thrown when a destination either is not understood by a provider or is no longer valid.
InvalidDestinationRuntimeException	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 a InvalidDestinationException to be thrown.
InvalidSelectorException	This exception must be thrown when a JMS client attempts to give a provider a message selector with invalid syntax.
InvalidSelectorRuntimeException	This unchecked exception must be thrown when a JMS client attempts to give a provider a message selector with invalid syntax, and the method signature does not permit a InvalidSelectorException to be thrown.
JMSConnectionFactory	This annotation may be used to specify the JNDI lookup name of a javax.jms.ConnectionFactory to be used when injecting a javax.jms.JMSContext object.
JMSConnectionFactoryDefinition	An application may use this annotation to specify a JMS ConnectionFactory resource that it requires in its operational environment.
JMSConnectionFactoryDefinitions	Specifies one or more JMSConnectionFactoryDefinition annotations.
JMSConsumer	A client using the simplified JMS API introduced for JMS 2.0 uses a JMSConsumer object to receive messages from a queue or topic.
JMSContext	A JMSContext is the main interface in the simplified JMS API introduced for JMS 2.0.
JMSDestinationDefinition	An application may use this annotation to specify a JMS Destination resource that it requires in its operational environment.
JMSDestinationDefinitions	Specifies one or more JMSDestinationDefinition annotations.
JMSException	This is the root class of all checked exceptions in the JMS API.
JMSPasswordCredential	This annotation may be used to specify the userName and password to be used when injecting a javax.jms.JMSContext object.
JMSProducer	A JMSProducer is a simple object used to send messages on behalf of a JMSContext.
JMSRuntimeException	This is the root class of all unchecked exceptions in the JMS API.
JMSSecurityException	This exception must be thrown when a provider rejects a user name/password submitted by a client.
JMSSecurityRuntimeException	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 a JMSSecurityException to be thrown.
JMSSessionMode	This annotation may be used to specify the session mode to be used when injecting a javax.jms.JMSContext object.
MapMessage	A MapMessage object is used to send a set of name-value pairs.
Message	The Message interface is the root interface of all JMS messages.
MessageConsumer	A client uses a MessageConsumer object to receive messages from a destination.
MessageEOFException	This exception must be thrown when an unexpected end of stream has been reached when a StreamMessage or BytesMessage is being read.
MessageFormatException	This exception must be thrown when a JMS client attempts to use a data type not supported by a message or attempts to read data in a message as the wrong type.
MessageFormatRuntimeException	This unchecked exception must be thrown when a JMS 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 a MessageFormatException to be thrown.
MessageListener	A MessageListener object is used to receive asynchronously delivered messages.
MessageNotReadableException	This exception must be thrown when a JMS client attempts to read a write-only message.
MessageNotWriteableException	This exception must be thrown when a JMS client attempts to write to a read-only message.
MessageNotWriteableRuntimeException	This unchecked exception must be thrown when a JMS client attempts to write to a read-only message.
MessageProducer	A client uses a MessageProducer object to send messages to a destination.
ObjectMessage	An ObjectMessage object is used to send a message that contains a serializable object in the Java programming language ("Java object").
Queue	A Queue object encapsulates a provider-specific queue name.
QueueBrowser	A client uses a QueueBrowser object to look at messages on a queue without removing them.
QueueConnection	A QueueConnection object is an active connection to a point-to-point JMS provider.
QueueConnectionFactory	A client uses a QueueConnectionFactory object to create QueueConnection objects with a point-to-point JMS provider.
QueueReceiver	A client uses a QueueReceiver object to receive messages that have been delivered to a queue.
QueueRequestor	The QueueRequestor helper class simplifies making service requests.
QueueSender	A client uses a QueueSender object to send messages to a queue.
QueueSession	A QueueSession object provides methods for creating QueueReceiver, QueueSender, QueueBrowser, and TemporaryQueue objects.
ResourceAllocationException	This exception is thrown when a provider is unable to allocate the resources required by a method.
ResourceAllocationRuntimeException	This unchecked exception is thrown when a provider is unable to allocate the resources required by a method.
ServerSession	A ServerSession object is an application server object that is used by a server to associate a thread with a JMS session (optional).
ServerSessionPool	A ServerSessionPool object is an object implemented by an application server to provide a pool of ServerSession objects for processing the messages of a ConnectionConsumer (optional).
Session	A Session object is a single-threaded context for producing and consuming messages.
StreamMessage	A StreamMessage object is used to send a stream of primitive types in the Java programming language.
TemporaryQueue	A TemporaryQueue object is a unique Queue object created for the duration of a Connection.
TemporaryTopic	A TemporaryTopic object is a unique Topic object created for the duration of a Connection.
TextMessage	A TextMessage object is used to send a message containing a java.lang.String.
Topic	A Topic object encapsulates a provider-specific topic name.
TopicConnection	A TopicConnection object is an active connection to a publish/subscribe JMS provider.
TopicConnectionFactory	A client uses a TopicConnectionFactory object to create TopicConnection objects with a publish/subscribe JMS provider.
TopicPublisher	A client uses a TopicPublisher object to publish messages on a topic.
TopicRequestor	The TopicRequestor helper class simplifies making service requests.
TopicSession	A TopicSession object provides methods for creating TopicPublisher, TopicSubscriber, and TemporaryTopic objects.
TopicSubscriber	A client uses a TopicSubscriber object to receive messages that have been published to a topic.
TransactionInProgressException	This exception is thrown when an operation is invalid because a transaction is in progress.
TransactionInProgressRuntimeException	This unchecked exception is thrown when an operation is invalid because a transaction is in progress.
TransactionRolledBackException	This exception must be thrown when a call to Session.commit results in a rollback of the current transaction.
TransactionRolledBackRuntimeException	This unchecked exception must be thrown when a call to JMSContext.commit results in a rollback of the current transaction.
XAConnection	The XAConnection interface extends the capability of Connection by providing an XASession (optional).
XAConnectionFactory	The XAConnectionFactory interface is a base interface for the XAQueueConnectionFactory and XATopicConnectionFactory interfaces.
XAJMSContext	The XAJMSContext interface extends the capability of JMSContext by adding access to a JMS provider's support for the Java Transaction API (JTA) (optional).
XAQueueConnection	An XAQueueConnection provides the same create options as QueueConnection (optional).
XAQueueConnectionFactory	An XAQueueConnectionFactory provides the same create options as a QueueConnectionFactory (optional).
XAQueueSession	An XAQueueSession provides a regular QueueSession, which can be used to create QueueReceiver, QueueSender, and QueueBrowser objects (optional).
XASession	The XASession interface extends the capability of Session by adding access to a JMS provider's support for the Java Transaction API (JTA) (optional).
XATopicConnection	An XATopicConnection provides the same create options as TopicConnection (optional).
XATopicConnectionFactory	An XATopicConnectionFactory provides the same create options as a TopicConnectionFactory (optional).
XATopicSession	An XATopicSession provides a regular TopicSession.