Introduction to Object-Oriented Technology

• Components of Object-Oriented Technology
• Different Kinds of Programming and Design Philosophy
• Object-Oriented Programming Languages
• Object-Oriented Analysis and Design Methods

1. Components of Object-Oriented Technology

• Object-oriented programming languages and environments
• Object-oriented analysis and design methods

1.1 Object-oriented programming languages and environments

• First object-oriented language, Simula at 1967
• Proved by Smalltalk at 1976s
• C++, Effiel, Common Lisp, Object-Pascal, ... appeared at late 1970s
• Object-oriented orogramming environments matured at 1980s
• user interface (1980s) : WIMP, Dynabook, Apple Lisa and Macintosh, Window systems, …
• Java appeared at 1995

1.2 Object-oriented analysis and design methods

• Programming environments only do not make good systems
• A lot of bject-oriented analysis and design methods appeared at late 1980s and early 1990s
• UML recognized by OMG as standard at Nov. 1997

1.3 Methods

• Components of a method
• a modeling language or notation
• a process
• guidelines
• applying examples of typical problems
• Well-known methods
• structured analysis and design methods
• Shlaer and Mellor's books on OOA&D
• Coad and Yourdon's books on OOA
• Booch method
• Rumbaugh's OMT
• Jacobson's OOSE
• Wirfs-Brock, Beck and Cunningham's CRC
• ...

2. Different Kinds of Programming and Design Philosophy

2.1 Process-oriented (or function-oriented) concepts

• emphasizing on processes or functions
• viewing a system as a process or function and then decompose the function into sub-functions, …
• data management is weak and underestimated
• problems

2.2 Data-oriented concepts

• emphasizing on data analysis
• starting the system analysis process from data analysis
• very weak in processing considerations
• the results of these two kinds of analysis cannot be easily combined

2.3 Objec-oriented concepts

• Object (instance) : member data + methods (operations)
• Class (object type) : the definition of objects
• The construct of an object-oriented system - classes
• The operation of an object-oriented system
• objects
• invoking a method
• message and message passing
• Balancing data and process

2.4 Properties of object-oriented technology

• Class => abstraction
• Encapsulation => data hiding
• Inheritance => reuse
• Dynamic binding => polymorphism=>flexible
• Software reuse
• Object-based languages versus object-oriented languages

3. Object-Oriented Programming Languages

3.1 Smalltalk

• Developed by Xerox Palo Alto Research Center.
• A purely object-oriented language and environment, i.e., anything is an object
• Powerful in graphical user interface construction
• The first language that sucessfully demonstrates the power of object-oriented concept

3.2 C++

• Deveopled by Bjarne Stroustrup at Bell Lab.
• Extending from C with object-oriented concept
• Widely used in many applications' and systems' developments

3.3 Java

• History of Java
• Green project funded by Sun for intelligent consumer electronic devices
• announced at May 23, 1995
• experiences from CE
• so many kinds of machines, portability
• simple
• no hard disk => network download
• security
• The properties of Java
• A simple, object-oriented, distributed, interpreted, robust, secure, architecture-neutral, portable, high performance, multithreaded, dynamic language -- commented by Sun
• "Write once, run anywhere"
• Why Java
• object-oriented
• subset of C++
• hot language on internet

4. Object-Oriented Analysis and Design Methods

4.1 So many methods appeared since late 1980s

• the method's scene was pretty split and competitive
• all the methods were very similar
• they, however, contained a number of often annoying minor differences among them
• therefore, a basic concepts would appear in very different notations

4.2 Unified Modelling Language

• OOPSLA’94
• Rational Software
• UML by Booch, Rumbaugh, and Jacobson
• a modeling language but not a method
• current status
• accepted by OMG as a standard object-oriented modelling language at Nov. 1997
• already become a starndard modeling language just as DFD notation in traditionaly structured analysis
• wide industry support
• version 1.3
• related books
• Booch - User Guide
• Rumbaugh - Reference Manual
• Jacobson - Development Process
• ...
• tool support
• Rational Rose 2000
• ...

4.3 Developing Process

• UML is just a standard modelling language,  one may employ any kind of developing process
• Use case driven developing process is the most frequently used one
• Use case driven process first realized by Jacobson
• Rose Objectory process

Reference:

• What Is OMG-UML and Why Is It Important?
• UML Q&A
• The origin and descent of UML (from CACM, Oct. 1999)

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作者: 銘傳大學 資訊工程研究所許銀雄
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