Monday, January 21, 2013

Week-1 : 1.1: Fundamental Knowledge

One of the difficult things about getting started with Java is installing everything you need. Even before you write a single line of code, the headaches begin! Hopefully, the following sections will make life easier for you. We're going to write all our code using a free piece of software called NetBeans. This is one of the most popular IDEs (Interface Development Environment) in the world for writing Java program. You'll see what it looks like shortly. But before NetBeans will work, it needs you to install the necessary Java components and files. First up is something called the Java Virtual Machine.

The Java Virtual Machine

Click Here for DetailsJava is platform independent. This means that it will run on just about any operating system. So whether your computer runs Windows, Linux, Mac OS, it's all the same to Java! The reason it can run on any operating system is because of the Java Virtual Machine. The Virtual Machine is a program that processes all your code correctly. So you need to install this program (Virtual Machine) before you can run any Java code.
Java is owned by a company called Sun Microsystems, so you need to head over to Sun's website to get the Java Virtual Machine, also known as the Java Runtime Environment (JRE). Try this page first:

You can check to see if you already have the JRE on your computer by clicking the link "Do I have Java?". You'll find this link under the big Download button at the top of the page. (Unless Sun have changed things around, again!) When you click the link, your computer will be scanned for the JRE. You will then be told whether you have it or not. If not, you'll be given the opportunity to download and install it.
Or you could just head over to this page:

The "manual" in the above links means "manual download". The page gives you download links and instructions for a wide variety of operating systems.
After downloading and installing, you may need to restart you computer. When you do, you will have the Java Virtual Machine.

The Java Software Development Kit

At this stage, you still can't write any program. The only thing you've done is to install software so that Java program can be run on your computer. To write code and test it out, you need something called a Software Development kit.
Java's Software Development Kit can currently be downloaded from here:
The one we're going to be using is called Java SE. (The SE stands for Standard Edition.). Click on that link, then on "Java SE (JDK) 6 Download". You'll then find yourself on a page with a bewildering list of options to download. Because we're going to be using NetBeans, locate this:

JDK 6 Update X with NetBeans 6.x

Click the Download link to be taken to yet another page. Click the top download to be taken to a page that asks you to select your operating system. Click Continue to finally get the download you need. A word of warning, though - this download will be big, at over 130 megabytes at the time of writing! Once you've downloaded the JDK and NetBeans, install it on your computer.
We're going to be using NetBeans to write our code. Before launching the software, however, here's how things work in the world of Java.

How things work in Java

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