Java Programming  «Prev  Next»
Lesson 3What you need
ObjectiveThis page discusses the requirements to learn about Java

Java TM Requirements

Software

You will need the following materials to take this course.
In order to work through the example programs presented throughout the course, you will need to acquire and install the Java 2 Software Development Kit (SDK), Standard Edition or some other suitable development environment with a Java compiler.
For information about other Java development environments, please visit the Resources page. Any development environment you use for this course should be Java 2 compliant.
There currently is not a release of the Java 2 SDK available for Mac OS or Linux computers. If you use one of these platforms you will not be able to compile and test the example Java code in this series. Ports for other platforms are in the works, as are third-party development environments that are Java 2 SDK compliant. For now, if you are a Mac or Linux user, you can work through the course and follow along by simply studying the examples.
You need to know how to run command-line applications, since the tools in the Java 2 Software Development Kit (SDK) are all command-line tools.


Course bookstore

After having read about the importance of Java, you now want to become involved with the following text.
OCA Java SE 8
This book contains helpful information.

Java Programming

The term programming is used in many contexts. We will discuss its meaning in the context of human-to-computer interaction. In the simplest terms, programming is the way of writing a sequence of instructions to tell a computer to perform a specific task. The sequence of instructions for a computer is known as a program. A set of well-defined notations is used to write a program. The set of notations used to write a program is called a programming language. The person who writes a program is called a programmer. A programmer uses a programming language to write a program. How does a person tell a computer to perform a task? Can a person tell a computer to perform any task or does a computer have a predefined set of tasks that it can perform? Before we look at human-to-computer communication, let us look at human-to-human communication. How does a human communicate with another human?
You would say that human-to-human communication is accomplished using a spoken language, for example, English, German, Hindi, etc. However, spoken language is not the only means of communication between humans. We also communicate using written languages or using gestures without uttering any words. Some people can even communicate sitting miles away from each other without using any words or gestures; they can communicate at thought level.
To have a successful communication, it is not enough just to use a medium of communication like a spoken or written language. The main requirement for a successful communication between two parties is the ability of both parties to understand what is communicated from the other party. For example, suppose there are two people. One person knows how to speak English and the other one knows how to speak German. Can they communicate with each other?
The answer is no, because they cannot understand each other's language. What happens if we add an English-German translator between them? We would agree that they would be able to communicate with the help of a translator even though they do not understand each other directly. Computers understand instructions only in binary format, which is a sequence of 0s and 1s. The sequence of 0s and 1s, which all computers understand, is called machine language or machine code. A computer has a fixed set of basic instructions that it understands. Each computer has its own set of instructions. For example, 0010 may be an instruction to add two numbers on one computer and 0101 is an instruction to add two numbers on another computer. Therefore, programs written in machine language are machine-dependent. Sometimes machine code is referred to as native code as it is native to the machine for which it is written. Programs written in machine language are very difficult, if not impossible, to write, read, understand, and modify.