Java Messaging Service With Topics Using JNDI

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Java Messaging Service With Topics Using JNDI

• Group 04
• Biragi Sripadmanaban
• Bakee Paramsothy
• Michael Moreno
• Peng-Sheng Cheng (Paul)
• Fa-Chih Chou (Jeremy)

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What is Messaging Service?

• Messaging is a way or a mechanism that provides
  communication between software applications,
  programs or objects on a distributed systems.
• Application-to-application messaging systems,
  when used in business systems, are generically
  referred to as enterprise messaging systems, or
  Message- Oriented Middleware (MOM).

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Cont ..

• In a messaging system there are clients that can
  send and receive messages.
• Each client connects to the messaging system,
  which provides a platform to create, send, and
  receive messages.
• A messaging system has three major features.

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Major Features of Messaging System

• A messaging system is loosely coupled. Senders
  and receivers dont have to be aware of each
  other.
• A messaging system isolates clients from each
  other.
• A messaging system allows decoupling. Senders and
  receivers dont have to be up and running at the
  same time.

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What is Java Messaging Service ?

• JMS provides a common way for Java programs to
  create, send, receive, and read an enterprise
  messaging system's messages.
• In other words, JMS is an java interface for a
  messaging service. It is for abstracting access
  to different message oriented middleware
  products.
• The API provides for asynchronous messaging,
  where a client can send a message and doesnt
  have to wait for the recipient to receive the
  message and process it.
• JMS application allow client applications
  server applications to perform actions in
  parallel, instead of serially.

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JMS Specification
JMS Client Application
JMS API
Messaging System
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Definition of JMS Client Provider

• JMS Provider
• Is the messaging agent that is responsible for
  managing the messaging service.
• JMS Clients
• Are applications components written in Java
  that use the provider for communication.

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Features of JMS

• Asynchronous
• A JMS client doesnt have to request messages to
  receive them. The JMS provider delivers messages
  to the client as the messages arrive.
• Reliable
• A JMS system can ensure that a message is
  delivered only once.

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JMS Messaging Models

• Publish and Subscribe
• Many consumers per message
• Point-to-point
• One consumer per message

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Publish-and-Subscribe
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Publish-and-Subscribe

• The publishing client addresses messages to a
  topic.
• A subscriber client may then retrieve the
  messages from that topic.
• Topics are deleted once they have been delivered
  to one or more subscribers.
• This is a one-to-many model.
• Example Radio Station

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Rules of Publish-Subscribe Model

• Each message may have multiple consumers.
• Default timing dependency between the publisher
  and subscriber.
• A subscriber may only consume messages delivered
  after they have initiated their subscription,
  the subscriber must remain active to consume
  messages.

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Point-to-Point
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Point-to-Point

• Client sends a message that is received only by
  one client.
• The sender sends a message to a queue and the
  receiver extracts this from the queue at any
  convenient time the receiver connects to the
  system.
• Messages are ordered in the order they were
  placed in the queue. (FIFO)
• A queue retains all messages it receives until
  the messages are consumed or until the messages
  expire.
• Example - U.S Postal Service