JAVA: A Beginner's Guide

Java is an object-oriented programming language developed by Sun Microsystems, a company best known for its high-end Unix workstations. Modeled after C++, the Java language was designed to be small, simple, and portable across platforms and operating systems, both at the source and at the binary level.

The Java language was developed at Sun Microsystems in 1991 as part of a research project to develop software for consumer electronics devices-television sets, VCRs, toasters, and the other sorts of machines you can buy at any department store. Java's goals at that time were to be small, fast, efficient, and easily portable to a wide range of hardware devices. It is those same goals that made Java an ideal language for distributing executable programs via the World Wide Web, and also a general-purpose programming language for developing programs that are easily usable and portable across different platforms. This is the major reason why Java is said to be the most successful platform independent language.

Java as a language has significant advantages over other languages and other programming environments that make it suitable for just about any programming task. Some of them are listed below:

Applets appear in a Web page much in the same way as images do, but unlike images, applets are dynamic and interactive. Applets can be used to create animations, figures, or areas that can respond to input from the reader, games, or other interactive effects on the same Web pages among the text and graphics. Java enabled browsers can successfully run applets and thus give a truly rich experience at the user end.

Platform Independence
Platform independence is one of the most significant advantages that Java has over other programming languages, particularly for systems that need to work on many different platforms. Java is platform-independent at both the source and the binary level. Platform-independence is a program's capability of moving easily from one computer system to another. Java binary files called byte-codes are also platform-independent and can run on multiple platforms without the need to recompile the source. Byte-codes are a set of instructions that look a lot like machine code, but are not specific to any one processor. Because of them, compilation happens just once; interpretation occurs each time the program is executed. Java byte-codes help make "write once, run anywhere" possible. 

In addition to its portability and object-orientation, one of Java's initial design goals was to be small and simple, and therefore easier to write, easier to compile, easier to debug, and, best of all, easy to learn. Keeping the language small also makes it more robust because there are fewer chances for programmers to make difficult-to-find mistakes. Despite its size and simple design, however, Java still has a great deal of power and flexibility. 

Better Cousin of C, C++
Java is modeled after C and C++, and much of the syntax and object-oriented structure is borrowed from the latter. If you are familiar with C++, learning Java will be particularly easy for you, because you have most of the foundation already. Although Java looks similar to C and C++, most of the more complex parts of those languages have been excluded from Java, making the language simpler without sacrificing much of its power. There are no pointers in Java, nor is there pointer arithmetic. Strings and arrays are real objects in Java. Memory management is automatic. To an experienced programmer, these omissions may be difficult to get used to, but to beginners or programmers who have worked in other languages; they make the Java language far easier to learn. 

Object Oriented Programming
Java is object-oriented programming (OOP) technique, which is merely a way of organizing programs for creating flexible, modular programs and reusing code. . Like most object-oriented programming languages, Java includes a set of class libraries that provide basic data types, system input and output capabilities, and other utility functions. Because these class libraries are written in Java, they are portable across platforms as all Java applications are. 

Applets and Applications
The most common types of programs written in the Java programming language are applets and applications. If you've surfed the Web, you're probably already familiar with applets. An applet is a program that adheres to certain conventions that allow it to run within a Java-enabled browser.

An application is a standalone program that runs directly on the Java platform. A special kind of application known as a server serves and supports clients on a network. Examples of servers are Web servers, proxy servers, mail servers, and print servers. Another specialized program is a servlet. A servlet can almost be thought of as an applet that runs on the server side. Java Servlets are a popular choice for building interactive web applications, replacing the use of CGI scripts. Servlets are similar to applets in that they are runtime extensions of applications. Instead of working in browsers, though, servlets run within Java Web servers, configuring or tailoring the server. 

Full implementation of the Java platform provides the essentials like objects, strings, threads, numbers, input and output, data structures, system properties, date and time. Both, low and high level security, including electronic signatures, public and private key management, access control, and certificates are provided by java platform. Networking management, Java Database Connectivity (JDBC), Remote Method Invocation (RMI) are some of the other features of Java. '

In my next article I will focus on the object oriented programming concepts. Java isn't all that tough as the various training institutes advertise. A good written matter on Java and lots of practice on your Java Development Toolkit (JDK) is all that you need to become a Java pro.  


More by :  Deepak Chandrasekaran

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