Object Orientated Analysis & Design Object Orientated FrameworkModel Comparisons By Mark Ar

Object Orientated Analysis & Design Object Orientated Framework/Model Comparisons By Mark Arena - 2003
Table of Contents Introduction ....................................................................................................................... 2 CORBA .............................................................................................................................. 3 DCOM ................................................................................................................................ 4 Comparing CORBA and DCOM..................................................................................... 5 J2EE ................................................................................................................................... 6 RMI..................................................................................................................................... 7 References .......................................................................................................................... 8
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Introduction Object Orientated Analysis and Design (OOA&D) frameworks are techniques used by professionals to drive the systems development process. “Analysis frameworks manage the data analysis process from algorithm development through data selection and retrieval” * The main frameworks which will be focused on are CORBA and DCOM but there are also others such as J2EE and RMI.
* (Tim Hallman & Torre Wenaus. 1999)
CORBA stands for Common Object Request Broker Architecture which is an open infrastructure which is mainly by applications that work over networks. “Thousands of sites rely on CORBA for enterprise, internet, and other computing.” * CORBA currently is an open standard maintained by the Object Management Group (OMG).
* (Object Management Group, 2002)
* (Object Management Group, 2002)
DCOM stands for Distributed Component Object Model and is a proprietary model owned by Microsoft. It allows “software components to communicate directly over a network in a reliable, secure and efficient manner”. It is based on the DCE-RPC specifications which have been created by the Open Software Foundation.
* (Microsoft Corp., 2002)
* (Microsoft Corp., 2002)
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CORBA CORBA applications are made up of objects which mostly if not always represent something in the real world. The main advantage of CORBA is that it separates clients and objects so they can be written in different programming languages which can tailor software solutions to different systems. CORBA currently supports the interoperability of the languages of C, C++, Java, COBOL, Smalltalk, Ada, Lisp, Python and IDLscript. The main core of CORBA is the idea where the interface and the implementation and separate. This allows objects to be encapsulated so the client can only see the objects through an interface which can limit operations. In CORBA also every object has its own electronic token uniquely identifying it to minimize conflicts and collisions. In the picture below the IDL (Interface Definition Language) stub acts like a proxy and sends requests to the Object Request Broker which in turn sends it to the skeleton and finally to the object where it is executed.
* (Object Management Group, 2000)
The IDL is the interface which is used to interpret and communicate between different programming languages. An example of an IDL interface is: “interface salestax { float calculate_tax ( in float taxable_amount ); }” In this instance the object’s type is “salestax” and it can perform the function “calculate_tax”. The object takes one input parameter, being “taxable_acount” which is float and has one output parameter which doesn’t need to be named and is also of type float.
* (Object Management Group, 2002)
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