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Min Chen School of Computer Science and Engineering Seoul National University. Data Structure: Java Programming 1. Introduction to java. Content. Overview of Java Integrated Development Environment (IDE) Install Java SE Introduction to Eclipse Setup your IDE in Windows
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Min Chen School of Computer Science and Engineering Seoul National University Data Structure: Java Programming 1 Introduction to java
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) Java Code (.java) Java Binary Files (.class) Compiler Java VM Runtime Interpreting Java Developer’s Kit (JDK) Machine Code
Install Java SE JDK • Website: • http://www.java.com/en/download/manual.jsp
IDE: Eclipse Integrated Development Environment • 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 • … …
Eclipse: Download • Website: • http://www.eclipse.org/downloads/
Start Eclipse • Steps • Extract the zip file into your hard disk • Double click torun “eclipse.exe” • Select your workspace directory
Writing Code for HelloWorld public static void main(String args[]) { System.out.print("Hello World in Java!"); }
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) Object-Oriented Programming: Process-Oriented Programming: Start Judgment System Black Turn Draw chessboard Y Black Win ? Chessboard System N White Turn Draw chessboard N White Win ? Black Player White Player Y End
Concept of Class CEO • Example 1 Name Gender Age Place of Birth Company Products
Concept of Class (cont.) Sportsman • Example 2 Name Gender Age Place of Birth Employer Sports League
Inheritance of Class People • Higher Abstract Name Gender Age Sportsman Place of Birth CEO Name Name Gender Sportsman Gender Age Age CEO Place of Birth Place of Birth Employer Employer Company Company Sports Sports Products Products League League
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 Constructed Function: Run when the object is initiated • CEO Class 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 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 Create an instance (steve) of Class CEO
Example Result • The system print out: Hello World in Java! My name is Steve Jobs