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: 

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: 

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!"); } 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… Name:Steve Jobs Gender:Male 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 Gender:Male Age:28 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