Rahul's Blog

In previous post we have seen the Introduction of Java language and its features. In this post I’ll demonstrate how to install Java on your Windows Operating System.

1. Downloading the Java

• The latest version of the Java can be downloaded from this link https://cds.sun.com/is-bin/INTERSHOP.enfinity/WFS/CDS-CDS_Developer-Site/en_US/-/USD/ViewProductDetail-Start?ProductRef=jdk-6u23-oth-JPR@CDS-CDS_Developer

2.  Installing the Java:

After the downloading is completed installation is very easy, just click the next buttons and agree the license agreements and the Java will be installed on your system.

Note: Setup asks you two times to install the files don’t cancel them. First time installer, installs the Java Development Kit (JDK) and second time installer, installs the Java Runtime Environment (JRE).

3. Configuring Java on Windows Operating System:

In this post I’ll show how to configure Java on Windows XP Operating System. The same process can be executed on the other versions of Windows. We will just register some environment variables which allows you to run the programs from command prompt.

• Go to the drive where you have installed Java. On my computer I have installed Java on “D:\Program Files\Java”  directory.
• Double click the “jdk1.7.0” directory. The version no. might be different, I am installing Java 7 so the version no. is 1.7.0, it might different version no also like 1.6.0 or 1.6.18 etc. I depends on which latest version of Java you have installed on your system.

• Double Click the “bin” directory

• Now copy the address from the address bar. For eg: “D:\Program Files\Java\jdk1.7.0\bin”

4. Registering Environment Variables:

• Now, right click on My Computer icon and select Properties.
• From the Properties dialog box, select the Advanced tab. In Advanced tab click on the Environment Variables button

• A new dialog box will appear on clicking the Environment Variables button.

• In above dialog box, select Path variable from System Variables and Click on Edit button. The Edit System Variable dialog will appear.

• Now edit the Variable value. Give a ; (semicolon) at the end of the Variable value field and paste the path that we had copied in this field i.e. “D:\Program Files\Java\jdk1.7.0\bin” and click ok.

• Note: Don’t Delete whole value from the Variable value field, If you have deleted the whole value then your computer will be crashed and you will not able to restart your computer.

• Close all the dialog boxes.

5.  Checking whether the Java is Installed or not:

• Open command prompt window and type the following command

java -version

• The above command on execution will display following results:

java version “1.7.0-ea”

Java(TM) SE Runtime Environment (build 1.7.0-ea-b121)

Java HotSpot(TM) Client VM (build 20.0-b03, mixed mode, sharing)

Now successfully you have installed Java on your Windows Operating System.

I am writing this post for giving just a small introduction of Java programming language.

Java:

Java is a programming language originally developed by James Gosling at Sun Microsystems (which is now a subsidiary of Oracle Corporation) and released in 1995 as a core component of Sun Microsystems’ Java platform. The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities. Java applications are typically compiled to byte code (class file) that can run on any Java Virtual Machine (JVM) regardless of computer architecture. Java is a general-purpose, concurrent, class-based, object-oriented language that is specifically designed to have as few implementation dependencies as possible. It is intended to let application developers “write once, run anywhere”. Java is currently one of the most popular programming languages in use, and is widely used from application software to web applications.

The Java technology is both a programming language and a platform. The Java programming language is a high level language that can be characterized by all the following buzzwords:

• Simple
• Object oriented
• Distributed
• Multithreaded
• Dynamic
• Portable
• High Performance
• Robust
• Secure

Java Platform:

A platform is a software or hardware environment where a program runs. The most popular platforms like Microsoft Windows, Linux, Solaris OS and Mac OS. Most platform can be described as the combination of the operating system and underlying hardware. The Java platform differs from most other platform in that its a software platform that runs on top of other hardware based platforms.

The Java platform has two components:

• Java Virtual Machine
• Java Application Programming Interface (API)

In the Java programming language, all source code is first written in plain text files ending with the .java extension. Those source files are then compiled into .classfiles by the javac compiler. A .class file does not contain code that is native to your processor; it instead contains bytecodes — the machine language of the Java Virtual Machine¹ (Java VM). The java launcher tool then runs your application with an instance of the Java Virtual Machine.

Because the Java VM is available on many different operating systems, the same .class files are capable of running on Microsoft Windows, the Solaris ^TM Operating System (Solaris OS), Linux, or Mac OS.

The API is a large collection of ready-made software components that provide many useful capabilities. It is grouped into libraries of related classes and interfaces; these libraries are known as packages.

As a platform-independent environment, the Java platform can be a bit slower than native code. However, advances in compiler and virtual machine technologies are bringing performance close to that of native code without threatening portability.