INM205Object Oriented Programming in

JAVA

Dr. Michael Casey

Department of Computing

INM205 SyllabusWeek Date Content Chapters

1 29/09 JAVA and object concepts: classes, instances and invocation 1

2 06/10 Anatomy of objects: types, expressions and scope. Assignment 1

2-3

3 13/10 ? Polymorphism: Shapes and Simple Graphics 4

4 20/10 ? Control structures: conditional behaviour 5

5 27/10 Iteration: Assignment 2 6

6 03/11 READING WEEK, NO LECTURE 9,10,11,12

7 10/11 Interfaces, Inheritance 9,10,11,12

8 17/11 Collections, Exceptions and Streams 13,16

9 24/11 Graphical User Interface (The SWING Library) 13,15

10 01/12 Developing Applications 1

11 08/12 Developing Applications 2

12 15/12 Exam Prep.

What this module is about

• Object-oriented programming languages • what they are • why they are the way they are • how to use them

• Java used as language to illustrate ideas

• software design not the main topic: • see Object-Oriented Analysis & Design (term 2)

What is a Computer ?

• Central processing unit

• Memory

• Peripherals

• Executes very simple instructions

• Executes instructions very rapidly

• General purpose device

• Programs describe specific actions

Computer Architecture

Computer Architecture

What is a Program ?

CPU

Data Bus

Inst

ruct

ion

s21 40 16 100 ...

What is a Program ?

CPU

Data Bus

Inst

ruct

ion

s21 40 16 100 ...

Machine Code: specific to a machine (e.g. CPU)

What is a Program ?

21 40 16 100 ...iload intRatebipush 100if_icmpgt intError

Assembly Language: specific to a machine

What is a Program ?

21 40 16 100 ...iload intRatebipush 100if_icmpgt intError

Assembly Language: specific to a machine

if (intRate>100)...

What is a Program ?

High-level Language: General Purpose (Not machine specific)

if (intRate>100)...

iload intRatebipush 100if_icmpgt intError

The JAVA Programming Language

• Clean Object-Oriented implementation

• Safe (for beginners)

• Platform independent “write once, run anywhere”

• Virtual Machine

• Rich library

• Widely-Used for Internet / Business / Academic

Classes and Objects

• class – a set of objects that support a specified set of operations

(methods). Analogy: a type of machine, with buttons, levers, displays, etc.

• object – an instance of a class: some data, usually hidden from

the rest of the program, and manipulated by the specified methods. Analogy: a particular machine of that type.

Car Class

Class

Car Class

Instance

Car Class

InstanceFields

Car Class

Two Instances

Car Class

Two Instances

One Class

Car Class

JamesBond car object instanceJamesBond car instance fields

Student LabClass Class

Two Classes

•LabClass•Student

Dependency

Student LabClass Class

identifierstudent1

Student LabClass Class

instance fields

Student LabClass Class

Methods

Shape Classes

Four Classes

Shape Classes

One instance

Shape Classes

Instance Methods

Shape Classes

Methods

Output (Canvas)

BlueJ and JAVA

BlueJ and JAVA

UML Class Diagram

BlueJ and JAVA

Object Instances

BlueJ and JAVA

Source Code Editor

JAVA Programming Flow Chart

JAVA Programming Flow Chart

JAVA Programming Flow Chart

JAVA Programming Flow Chart

JAVA Programming Flow Chart

JAVA Programming Flow Chart

JAVA Programming Flow Chart

Summary• What is a Computer ?

• CPU, Memory, Storage, I/O

• What is a Program ?• machine code, assembly language, high level language

• Objects• model things in the world• classes vs. object instances• instance fields, methods

• The JAVA Programming Flowchart• editing, compiling, running (interpreter)