IT 222 (Part 3)

• CORBA stands for Common Object Request Broker Architecture.
• OMG stands for Object Management Group.
• OMG is founded in 1989.
• OMG is a not-for-profit organization.
• OMG is vendor neutral.
• Key Specifications of OMG

  1. UML
  2. CORBA
• UML stands for Unified Modeling Language.
• CORBA defines a framework for object-oriented distributed applications.
• CORBA is defined by a consortium of vendors under the direction of OMG.
• CORBA allows distributed programs in different languages and different platforms to interact as though they were in a single programming language on one computer.
• CORBA brings advantages of object orientation to distributed systems.
• CORBA allows designing a distributed application as a set of cooperating objects and to reuse existing objects.
• Java RMI is a programming technology.
• CORBA is an integration technology.
• Key CORBA Features

  1. Application Development Transparencies
  2. CORBA Interface Definition Language (IDL)
  3. CORBA Services
  4. Interoperability
• Application Development Transparencies

  1. Hardware/Language neutral
  2. Vendor neutral
  3. Object oriented paradigm
• CORBA Services

  1. Naming
  2. Event
  3. Transaction
  4. Security
• ORB stands for Object Request Broker.
• ORB is a software component that mediates transfer of messages from a program to an object located on a remote host.
• ORB hides underlying network communications from a programmer.
• ORB allows you to create software objects whose member functions can be invoked by client programs located anywhere.
• In ORB, a server program contains instances of CORBA objects.
• When a client invokes a member function on a CORBA object, the ORB

  intercepts the function call.
• ORB directs the function call across the network to the target object.
• The ORB then collects the results from the function call and returns these to the function call.
• IDL: Used to generate application code (stubs/skeletons)
• IDL: Language neutral (Ada, C++, Java, ...)
• IDL is not a programming language.
• CORBA Objects: These are standard software objects implemented in any supported language including Java, C++, and Smaltalk.
• Each CORBA object has a clearly defined interface specified in CORBA IDL.
• The interface definition specifies the member functions available to the client without any assumption about the implementation of the object.
• To call a member function on a CORBA object the client needs only the object’s IDL.
• Client need not know the object’s implementation, location or operating system on which the object runs.
• Interface and implementation can be in two different languages.
• Interface abstracts and protects details (trade secret) from client.
• Interface offers a means of expressing design without worrying about implementation
• Interface is separated from implementation.
• IOR stands for by Interoperable Object References.
• module - package
• interface - interface