Java Messaging Service (JMS)

Presentation By

-Anil Prajapati

Messaging

Messaging is a method of communication between software components or applications.

A messaging system is a peer-to-peer facility. Messaging enables distributed communication

that is loosely coupled. Messaging differs from tightly coupled

technologies such as Remote Method Invocation (RMI )

Messaging also differs from electronic mail (e-mail)

What is JMS?

A specification that describes a common way for Java programs to create, send, receive and read distributed enterprise messages

loosely coupled communication Asynchronous messaging

A JMS provider can deliver messages to a client as they arrive; a client does not have to request messages in order to receive them.

Reliable delivery A message is guaranteed to be delivered once and only once.

Outside the specification Security services Management services

A JMS Architecture

JMS Clients Java programs that send/receive messages

Messages the objects that communicate information between JMS

clients Administered Objects

preconfigured JMS objects created by an admin for the use of clients

ConnectionFactory, Destination (queue or topic) JMS Provider

messaging system that implements JMS and administrative functionality

JMS Architecture

AdministrativeTool

JNDI Namespace

JMS Client JMS Provider

Bind

Lookup

LogicalConnection

CF D

Architecture Interaction

• The administrator binds connection factories (CF) and destinations (D) into a JNDI namespace.

• A JMS client can then lookup the administered objects and establish a logical connection to them via the JMS Provider

JMS Messaging Domains

Point-to-Point (PTP)

Publish-Subscribe systems

Request-Reply Messaging

Publish-Subscribe Messaging

When multiple applications need to receive the same messages, Publish- Subscribe Messaging is used.

The central concept in a

Publish-Subscribe messaging system is the Topic.

In Publish-Subscribe Messaging

is that, there may be multiple Senders and multiple Receivers.

Point- To-Point Messaging

When one process needs to send a message to another process, Point-To-Point Messaging can be used.

There are two basic types: • The first one involves a client

that directly sends a message to another client.

• The second and more common implementation is based on the concept of a Message Queue.

in Point-to-Point messaging even though there may be multiple Senders of messages, but there is only a single Receiver.

Request-Reply Messaging

When an application sends a message and expects to receive a message in return, Request-Reply Messaging can be used.

It could be: • Synchronous • Asynchronous JMS does not explicitly support Request-

Reply Messaging, though it allows it in the context of the other methods.

JMS API Programming Model

Connection

creates creates

creates

MsgDestination

receives from

sends to

ConnectionFactory

Destination

MessageConsumerSession

MessageProducer

creates

JMS Messages

Message Header used for identifying and routing messages contains vendor-specified values, but could also contain

application-specific data typically name/value pairs

Message Properties (optional) Message Body(optional)

contains the data five different message body types in the JMS

specification :-Bytes Messages ,Map Messages, Object Messages, Stream Messages , Text Messages

JMS Message Types

Message Type Contains Some MethodsTextMessage String getText,setText

MapMessage set of name/value pairs setString,setDouble,setLong,getDouble,getString

BytesMessage stream of uninterpreted bytes

writeBytes,readBytes

StreamMessage stream of primitive values

writeString,writeDouble,writeLong,readString

ObjectMessage serialize object setObject,getObject

Development in JMS

JMS API was first introduced in 1998 JMS provider may implement message-driven

beans to process messages concurrently. Message sends and receives can participate in

Java Transaction API (JTA) The JMS API allows for a very loosely coupled

interaction between J2EE applications and existing Enterprise Information system (EIS).

JMS Availability

Allaire Corporation - JRun Server BEA Systems, Inc. Brokat Technologies (formerly GemStone) IBM iPlanet (formerly Sun Microsystems, Inc. Java Message Queue) Oracle Corporation Pramati SilverStream Software, Inc. Sonic Software SpiritSoft, Inc. (formerly Push Technologies Ltd.) Talarian Corp. TIBCO Software, Inc.

Thank You