Problem

1
Problem

• Software is generally
• Behind schedule
• Over cost
• Defective
• Incorrect (not what the user wanted)
• The problem involves analysis, design, and
  implementation

2
Premise

• Software quality can be improved by
• Reducing defects
• Reducing maintenance/modification time
• Giving the users what they want

3
OO Paradigm

• Closes the cognitive gap between our view of
  the system and its implementation to minimize
  analysis and design errors
• Makes reuse possible so that system components
  can evolve toward a defect-free state
• Fosters a prototyping life-cycle which increases
  the interaction between users and analyzers,
  designers, and implementors

4
Gaps

• The object-oriented approach provides a closer
  match between our shared perceptions of reality
  and the languages and tools of analysis, design,
  and implementation.
• As a consequence, the communication gaps which
  can occur between the various system-building
  activities are potentially much smaller.

STRUCTURED
Requirements
Analysis/Logical Design
Physical Design / Implementation
OBJECT-ORIENTED
Requirements
Analysis/Logical Design
Physical Design / Implementation
5
Systems Development Life Cycle
6
Systems Development Life Cycle
Requirements Document
DFD / ERD
Functional Decomposition
Code
7
History of OO

• Three interwoven threads
• programming
• knowledge representation
• linguistics
• data modeling

OORA
OOA
OO
OODBMS
OOD
OOI
OOSE
KR
DM
OOPL
8
Building an OOS OOADI interacting activities
in an iterative, recursive, incremental
process(add your own buzz-words here)
OOA
OOI
OOD
9
Object-Oriented Domain Analysis (OODA)

• Includes existing systems, domain expert
  knowledge, domain theory, and domain technology
• Promotes reuse
• Creates, manages, and expands a repository of
  analysis and design artifacts, objects, and
  patterns.
• Spans projects as an ongoing effort

10
Object-Oriented Analysis (OOA)

• Focuses upon a particular system or application
  in a domain
• Draws upon and contributes to the repository
  (reuse)
• Models the problem space
• May model (parts of) the solution space

11
Object-Oriented Design (OOD)

• The bridge between conceptualization and
  implementation
• Logical OOD
• blends with OOA
• establishes a system architecture
• draws upon and contributes to the repository
  (reuse)
• includes the user interface
• Physical OOD
• blends with OOI
• modifies the results of analysis and logical
  design to accommodate the implementation
  environment

12
Object-Oriented Implementation or Programming
(OOI or OOP)

• Blends with physical OOD
• Involves coding, software engineering, and
  metrics
• May require special techniques to support a
  distributed environment

13
OOAD Methodologies/Notations/Approaches

• a partial list
• Beck Cunningham
• Berard
• Booch
• de Champeaux, Lea, Faure
• Coad Yourdon
• Emblay, Kurtz, Woodfield
• Firesmith
• Graham
• Henderson-Sellers Edwards
• Jacobson
• Lorenz
• Martin
• Martin Odell
• Meyer
• Rubin Goldberg ( Gibson)
• Rumbaugh, et al.
• Shlaer Mellor
• Wirfs-Brock, et al.

and the (current) winners are Notation
Process - UML (Booch, Jacobson, and Rumbaugh)
14
Warning!

• It is possible to write truly awful
  object-oriented programs.
• There is no substitute for
• intelligence
• experience
• taste
• work
• Presentation by Bjarne Stroustrup at the Second
  Annual Alan J. Perlis Symposium on Programming
  Languages as reported by Phil Pfeiffer in ACM
  SIGPLAN Notices, 28(9) 6-12, September 1993.

15
What is Java?
Java is a simple, object-oriented, distributed,
interpreted, robust, secure, architecture-neutral,
portable, high-performance, multithreaded, and
dynamic programming language. (Java is buzzword
compliant)
16
More officially

• Java is an object-oriented programming language
  from Sun Microsystems.
• It allows programmers to develop applets or
  standalone computer applications that run as any
  program written in another programming language.

17
Portability

• One of the most significant benefits of Java is
  its promise of write-once, run anywhere
  portability.
• This is especially important on the Internet,
  where applets on web pages might be downloaded
  and run on PCs, Apple iMacs, Web TV, Unix boxes
  and more.
• This portability is made possible by the java
  runtime environment -- also called the Java
  Virtual Machine, or JVM -- which is packaged with
  each currently popular browser.
• Standalone Java applications can be run on any
  computer that has the Java runtime environment
  installed.

18
Java vs. JavaScript

• Although the names are almost the same, Java is
  not the same as JavaScript!
• Java is an object-oriented programming language.
• JavaScript is a scripting language, implemented
  as an extension of HTML.

19
More Java vs. JavaScript

• The languages also differ in how each interacts
  with browsers and Web pages.
• You can use Java to create either standalone
  applications or applets that run within a
  browser.
• JavaScript works only within a browser and is not
  compiled. You cannot use it to develop standalone
  applications. It is used for writing short
  programs (scripts) such as log-on procedures.
• JavaScript originated as Netscape's LiveScript,
  but because of its similarity in syntax to Java,
  it was renamed JavaScript.

20
JavaScript Java

• Interpreted (not compiled) by client.
• Object-based. Code uses built-in, extensible
  objects, but no classes or inheritance.
• Code integrated with, and embedded in, HTML.
• Variable data types not declared (loose typing).
• Dynamic binding. Object references checked at
  run-time.
• Cannot automatically write to hard disk.
  
  

• Compiled on server before execution on client.
• Object-oriented. Applets consist of object
  classes with inheritance.
• Applets distinct from HTML (accessed from HTML
  pages).
• Variable data types must be declared (strong
  typing).
• Static binding. Object references must exist at
  compile-time.
• Cannot automatically write to hard disk.

21
Java Genealogy