INTRODUCTION TO JAVA

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Nov 18, 2013 (3 years and 11 months ago)

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INTRODUCTION TO JAVA

Data Structure: Java Programming 1

Min Chen

School of Computer Science and Engineering

Seoul National University

Content


Overview of Java


Integrated Development Environment (IDE)


Install Java SE


Introduction to Eclipse


Setup your IDE in Windows


Start a new Java Project


Object
-
Oriented Programming


Concept of Class


Method in Class


Class in Java Programming

Overview of Java


Began as an internal project in 1990


Named “Oak” first


Sun
Microsystem


Providing an alternative to the C++/C


Re
-
target Java to Internet in 1994


Versions


Java Card


Java ME (Micro Edition)


Java SE (Standard Edition)


Java EE (Enterprise Edition)

Features of Java


Object
-
Oriented Programming Language


Write Once, Run Anywhere


Java Virtual Machine (VM)

Machine Code

Java VM

Java Binary Files

(.class)

Java Code (.java)

Compiler

Runtime

Interpreting

Install Java SE JDK


Website:


http://www.java.com/en/download/manual.jsp

IDE: Eclipse


A powerful IDE for Java development


As Microsoft Visual C++ for C++/C Development


Totally Free of Use !!!


A large number of Plug
-
in


Enable C++ development


Enable Website Design


… …


Integrated Development Environment

Eclipse: Download


Website:


http://www.eclipse.org/downloads/

Start Eclipse


Steps

1.
Extract the zip file into your hard disk

2.
Double click to run “eclipse.exe”

3.
Select your workspace directory

Start a new Java Project

Writing Code for
HelloWorld

public static void main(String
args
[])

{


System.
out.print
("Hello World in Java!");

}

HelloWorld
: Result

Object
-
Oriented Programming


Process
-
Oriented Programming


Focus on a flow process


Separates the concerns of data structures and the
concurrent processes that act upon them


Object
-
Oriented Programming


Uses "objects"


data structures consisting of
datafields

and

methods

together with their
interactions


to design applications


Feature


Information hiding, Data abstraction, Encapsulation,
Modularity, Polymorphism, Inheritance

Object
-
Oriented Programming


Example:
Gobang

Game (
five
-
in
-
a
-
row
)

Start

Black Turn

Draw chessboard

Black Win ?

End

White Turn

Draw chessboard

White Win ?

Y

N

Y

N

Process
-
Oriented

Programming:

Object
-
Oriented

Programming:

Chessboard

System

Judgment

System

White
Player

Black
Player

Concept of Class


Example 1

Name:

Bill Gates

Gender:

Male

Age:

54

Born:

U.S.

Company:

Microsoft

Products:

Windows,
Office…

乡浥N

却S癥v䩯Js

䝥湤G爺

䵡汥

Age:

54

Born:

U.S.

Company:

Apple

Inc.

Products:

Mac, iPod,

iPhone


CEO

Name

Gender

Age

Place of Birth

Company

Products

Concept of Class (cont.)


Example 2

Name:

박지성

䝥湤G爺

䵡汥

䅧攺



Born:

Korea

Employer:

Man. United

Sports:

Football

League:

Premier

Name:

Yao Ming

Gender:

Male

Age:

29

Born:

China

Employer:

Rockets

Sports:

Basketball

League:

NBA

Sportsman

Name

Gender

Age

Place of Birth

Employer

Sports

League

Inheritance of Class


Higher Abstract

CEO

Name

Gender

Age

Place of Birth

Company

Products

Sportsman

Name

Gender

Age

Place of Birth

Employer

Sports

League

Name

Gender

Age

Place of Birth

People

Sportsman

Employer

Sports

League

CEO

Company

Products

Method in Class


A class is not just a collection of data (we call
it
attribute
), but also a collection of methods


Method


As the function in C++/C


Define procedure with input and output


Example:


People


Think()


Eat()


Sleep()

Summary of Class


Consist of Attributes and Methods


Represents a collection of data and functions
which have relationship to each other


Other features


Information hiding


Data abstraction


Encapsulation


Modularity


Polymorphism


Inheritance


Class in Java Programming


Personally, I classify the Classes in Java
Programming into two types:


Entrance Class (Project Class)


With main method in the Class


The entrance and control center of the whole
program


Accessories Class


Provide functional part


Call in the main function to create instance

HelloWorld.java is an
Entrance Class

The method in Accessories Class
being called should be public!

Example


CEO Class

Constructed Function:

Run when the object is initiated

Define the attributes
for Class CEO

Set to be public so that the
function in CEO can be
called in other Class

Example (cont.)


HelloWorld

Class

Create an instance
(
steve
) of Class CEO

Reset the name of the
instance by the method
setName

in Class CEO

Get the name of the
instance by the method
getName

in Class CEO

Example Result


The system print out:

Hello World in Java!

My name is Steve Jobs

Thank you