Web Programming with Java - Introduction to Java docx

Web Programming with JavaIntroduction to Java Huynh Huu Viet Email: viethh@uit.edu.vn Department of Information Systems... What is Java?™ An object-oriented programming language develope

Web Programming with Java

Introduction to Java

Huynh Huu Viet Email: viethh@uit.edu.vn

Department of Information Systems

™ What is Java?

ƒ A little bit history

ƒ Major features

™ Where Java is used?

™ Key terms

™ A Simple Java Program

™ IDE: NetBeans

™ Resources

™ Discussion

What is Java?

™ An object-oriented programming language developed by Sun Microsystems

™ Also a platform to support Java applications (technology)

™ A little bit history

ƒ 1991: A team led by James Gosling at Sun

Microsystems developed Oak, for use in embedded consumer electronic appliances

ƒ 1995: renamed Java - redesigned for developing

Internet applications (Java 1.0 1.1).

ƒ 1998: Sun announced the Java 2 platform

(1.2,1.3,1.4)

ƒ 2005 - Now: Java 5 (Java 1.5 - newest version 1.7)

Java major features (1)

™ Simple

ƒ A bit easier C++.

ƒ The clean syntax

™ Object-Oriented

ƒ Reuse code

™ Distributed

ƒ Designed to make distributed computing easy

ƒ Writing network programs as sending and receiving data to and from a file.

™ Secure:

ƒ Based on the premise that nothing should be trusted.

Java major features (2)

™ Platform-independent

ƒ One program that will run on any platform with JVM

™ Portable

without being recompiled

™ Multithreaded

ƒ Program’s capability to perform several tasks simultaneously.

ƒ A necessity in multimedia and network

programming

Where Java is used?

™ Desktop standalone applications

™ Web applications

ƒ Client side: applets

ƒ Server side: Java servlets or JavaServer

Pages (JSP)

™ Embedded applications for small

hand-held devices

Key terms(1)

™ Java language specification (JLS):

ƒ Syntax and semantics of the Java programming

language

™ Java API

ƒ Predefined classes and interfaces for developing

Java programs

ƒ JLS is stable, but the API is still expanding

™ Java API – 3 Editions

ƒ Java 2 Standard Edition (J2SE): develop client-side standalone applications or applets

ƒ Java 2 Enterprise Edition (J2EE): develop server-side applications: Java servlets and JavaServer Pages

ƒ Java 2 Micro Edition (J2ME): develop applications for mobile devices

Key terms(2)

™ JDK- Java Development Kit ( SDK -System

Development Kit)

ƒ Programs for developing and testing Java programs

™ JRE - Java Runtime Environment

ƒ Programs for running Java programs

ƒ Includes: interpreter, core classes, and supporting files

ƒ A subset of JDK

™ IDE- Integrated Development Environment

ƒ Java development tool for rapidly developing Java programs

ƒ Three major IDE:

• JBuilder by Borland ( http://www.borland.com/ )

• NetBeans Open Source by Sun ( http://www.netbeans.org/ )

• Eclipse Open Source by IBM ( http://www.eclipse.org/ )

Key terms(3)

A Simple Java Program(1)

A Simple Java Program(2)

Anatomy of a Java Program

™ Comments

™ Reserved words

™ Modifiers

™ Statements

™ Blocks

™ Classes

™ Methods

™ The main method

Anatomy of a Java Program(1)

™ Comments

ƒ Line comment: //

ƒ Paragraph comment : /*…*/

™ Reserved words or keywords

ƒ Have a specific meaning to the compiler: class, public…

ƒ Java is case-sensitive

™ Modifiers

ƒ Keywords that specify the properties of the data,

methods, and classes and how they can be used.

ƒ public, static, private, final, abstract, and protected

™ Statements

ƒ Represents an action or a sequence of actions.

Anatomy of a Java Program(2)

™ Blocks

ƒ Begins with an opening brace ({)

ƒ Ends with a closing brace (})

™ Classes

ƒ The essential Java construct

ƒ Java program is classes

™ Methods:

ƒ Consists of a collection of statements that perform a sequence of operations

™ The main method

ƒ Defines where the program execution begins

Netbeans (1)

Netbeans (2)

™ Sun’s free, open source IDE for Java

™ Written in Java, available on any

platform that Java is available on

™ Supports plugins for working in other languages as well, such as C and C++.

™ Current Version

™ Available: http://www.netbeans.org

Netbeans (3)

™ JDK 6:

ƒ http://java.sun.com/javase/downloads/index.jsp

™ Java API (chm format):

ƒ http://www.allimant.org/javadoc/index.php

™ Netbeans IDE:

ƒ http://www.netbeans.org/index.html

™ Text Books:

sub-forum

Readings & Exercise

™ Further Readings

ƒ Chapter 1 [1], Chapter 2 [3]

™ Exercises:

ƒ [1]: 1.1

ƒ [3]: 2.14

™ Next week readings:

ƒ [1]: Chapter 2,3,4

Discussion