Starting Java Programming

Contributed and maintained by Aramadia Projects

September 2007

See full version with pictures here

This tutorial covers:

• • Java 6 Update 2 FREE!

  • Eclipse Editor FREE!

• Hello world

This document takes you through the basics of writing your first Java program. No prior experience is required except basic computer literacy.

I’m Lost!

Java is a powerful programming language maintained by Sun Microsystems. A program is simply a set of instructions that allows you to control a computer, and a “language” is the form of communicating your ideas to the computer. There are many languages like C++ and Pascal, in the same way “humans” can communicate in English or French. In order to “write” a program, we need an editor to type the instructions into. While notepad is perfectly capable of writing Java programs, the Eclipse IDE will give you more functionality.

Java and Eclipse are great because they are free. You don’t have to pirate Microsoft Visual Studio .NET 2005 (can make Photoshop CS3 cheap) but rather just download it.

Expected duration: 30 minutes

Prerequisites

This tutorial assumes you have some basic knowledge of, or programming experience with, the following technologies.

• Nothing!

Software Needed for the Tutorial

Before you begin, you need to install the following software on your computer (walkthrough in this tutorial):

• • Java Standard Development Kit (JDK™) version 1.6.2

• Eclipse IDE

Notations Used in the Tutorial

• • <ECLIPSE_HOME> - the Eclipse IDE installation directory

• <PROJECT_HOME> - directory that contains the project you create.

Tutorial Exercises

• • Exercise 0: Configuring your Computer

  • Exercise 1: Installing Java

  • Exercise 2: Installing Eclipse

• Exercise 3: Writing your First Program

Exercise 0: Configuring your Computer

Here are the basic pre-requisites your computer should have

• • High speed internet access

  • Decent processor (P4 or AMD64 and later)

  • 1GB RAM highly preferred

  • Windows XP /Linux/ Mac OS(Java is a multiplatform environment, it can be run on any operating system)

  • Big screen 1280x1024 or better (otherwise it gets cluttered)

• Administrator Access!

These aren’t necessary, but highly recommended.

Exercise 1: Installing Java

The goal of this exercise is to get Java on your computer. A lot of people get these terms confused:

Java SE, Java EE and Java ME

· Java SE – this is the standard edition: the one you want.

· Java EE – Enterprise Edition. Only required for advanced networking and database stuff. Really boring, don’t bother

· Java ME – Micro Edition. Used to program cell phones and PDAs.

Java JRE versus JDK

· Java JRE –Java Runtime Environment allows you to run Java programs

· Java JDK – Java Development Kit allows you to write and run Java programs. You don’t need to install the JRE if you install the JDK.

Installation (60 MB)

• 1. Go to http://java.sun.com/javase/downloads/index.jsp

  2. Click Download for JDK 6 Update 2

  3. Click on “Accept license agreement”

  4. Check of the appropriate installation. Only select one. For example Windows users should download the offline installation.

1. Follow the instructions, keep hitting next.

Check Installation

Go to your java installation directory and you should see jdk and jre folders.

Exercise 2: Installing Eclipse

Eclipse is a popular editor used for Java development. Its main competitor is NetBeans, but for simplicity’s stake, lets all use Eclipse.

Installation (78MB)

• 1. Go to http://www.eclipse.org/downloads/

  2. Download Eclipse IDE for Java (Click on the appropriate operation system)

  3. Copy your Eclipse zip file to a location of your preference (C:\ is the best because Eclipse tends to make filenames bigger than what your OS can handle)

1. Extract using your favorite unzipper (I recommend WinRAR)

Running Eclipse for the First Time

Eclipse stores all the program data in the installation directory. However, it keeps all user-created data and preferences in an area called the workspace. You do NOT have to copy your entire program directory, simply make sure you have the copy of the workspace to transfer data between computers.

• 1. Designate a workspace. I recommend (\My Documents\Eclipse Workspace)

1. You should see the welcome screen. Simply go through some of the basics or hit “Go to workbench”. You should see something like this (without anything inside):

Summary

You now have all the tools to do be a real programmer.

Exercise 3: Writing your First Program

I recommend you go through this with someone who already knows how. Programming is a social activity. If you go solo, you can easily get stuck for a week at a time. Ask your friends, senior programmers or go to one of the thousand internet forums. Google is your friend.

Hello World

It is traditional to start learning any program by instructing your program to print “Hello World”.

1. Make sure you have Eclipse and Java installed

2. Open Eclipse

3. Go to Windows->Open Perspective-> Java

4. Then go Windows->Reset Prespective. Hit yes. This ensures that the layout is correct. Eclipse is a highly customizable program, so its important to keep perspectives (or pre-made layouts).

5. Go to File -> New -> Java Project

6. Fill in the blank Project name:

7. Click Finish

8. You should see your project in the “Package Explorer”. Its on the left hand side.

9. Left click the project title so it is highlighted. This sets the “active” project if you have many projects.

10. Go to File -> New -> Class

11. Type “main” in Name:

12. Check the box “public static void main…”

13. Click Finish

Now we can begin coding!

You should see this is the editor window:

Now write this single line of code under the TODO line:

System.out.println(“Hello World”);

Remember to copy each word exactly, even that semicolon. It should look like this:

Go to Run -> Debug or simply hit F11. You should see the program output in the console window.

Summary

You are now a programmer. (You achieved Level 1 – fresh meat) There are more then 100 levels.

Next Steps

To send comments and suggestions, get support, and keep informed on the latest developments contact starcraft789@hotmail.com.