Java

Introduction to Java

Java is a programming language originally developed by James Gosling at Sun Microsystems (now part 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 bytecode (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, particularly for client-server web applications. The original and reference implementation Java compilers, virtual machines, and class libraries were developed by Sun from 1995. As of May 2007, in compliance with the specifications of the Java Community Process, Sun relicensed most of its Java technologies under the GNU General Public License. Others have also developed alternative implementations of these Sun technologies, such as the GNU Compiler for Java and GNU Classpath.

Java was conceived by James Gosling, Patrick Naughton, Chris Warth, Ed Frank, and Mike Sheridan at Sun Microsystems, Inc. in 1991. It took 18 months to develop the first working version. This language was initially called “Oak” but was renamed “Java” in 1995. Between the initial implementation of Oak in the fall of 1992 and the public announcement of Java in the spring of 1995, many more people contributed to the design and evolution of the language. Bill Joy, Arthur van Hoff, Jonathan Payne, Frank Yellin, and Tim Lindholm were key contributors to the maturing of the original prototype. Somewhat surprisingly, the original impetus for Java was not the Internet! Instead, the primary motivation was the need for a platform-independent (that is, architectureneutral) language that could be used to create software to be embedded in various consumer electronic devices, such as microwave ovens and remote controls. As you can probably guess, many different types of CPUs are used as controllers. The trouble with C and C++ (and most other languages) is that they are designed to be compiled for a specific target. Although it is possible to compile a C++ program for just about any type of CPU, to do so requires a full C++ compiler targeted for that CPU. The problem is that compilers are expensive and time-consuming to create. An easier—and more cost-efficient—solution was needed. In an attempt to find such a solution, Gosling and others began work on a portable, platform-independent language that could be used to produce code that would run on a variety of CPUs under differing environments. This effort ultimately led to the creation of Java. About the time that the details of Java were being worked out, a second, and ultimately more important, factor was emerging that would play a crucial role in the future of Java. This second force was, of course, the World Wide Web. Had the Web not taken shape at about the same time that Java was being implemented, Java might have remained a useful but obscure language for programming consumer electronics. However, with the emergence of the World Wide Web, Java was propelledto the forefront of computer language design, because the Web, too, demanded portable programs.

Java as an Internet Language

1. Java is an object oriented language and a very simple language. Because it has no space for complexities. At the initial stages of its development it was called as OAK. OAK was designed for handling set up boxes and devices. But later new features were added to it and it was renamed as Java. Java became a general purpose language that had many features to support it as the internet language. Few of the features that favors it to be an internet language are:
2. Cross Platform Compatibility: The java source files (java files with .java extension) after compilation generates the bytecode (the files with .class extension) which is further converted into the machine code by the interpreter. The byte code once generated can execute on any machine having a JVM. Every operating system has it's unique Java Virtual Machine (JVM) and the Java Runtime Environment (JRE).
3. Support to Internet Protocols: Java has a rich variety of classes that abstracts the Internet protocols like HTTP , FTP, IP, TCP-IP, SMTP, DNS etc .
4. Support to HTML: Most of the programming languages that are used for web application uses the html pages as a view to interact with the user. Java programming language provide it's support to html. For example. Recently the extension package jipxhtml is developed in java to parse and create the html 4.0 documents.
5. Support to Java Reflection APIs: To map the functionalities, Java Reflection APIs provides the mechanism to retrieve the values from respective fields and accordingly creates the java objects. These objects enables to invoke methods to achieve the desired functionality.
6. Support to XML parsing: Java has JAXP-APIs to read the xml data and create the xml document using different xml parsers like DOM and SAX. These APIs provides mechanism to share data among different applications over the internet.
7. Support to Web Services : Java has a rich variety of APIs to use xml technology in diverse applications that supports N-Tiered Enterprise applications over the internet. Features like JAXB , JAXM, JAX-RPC , JAXR etc enables to implement web services in java applications. It makes java a most suited internet language.
8. Support to java enabled Mobile devices: Java programming language is made in such a way so that it is compatible with mobile devices also. Java language also works with any java enabled mobile devices that support MIDP 1.0/2.0 including the symbian OS mobile devices.
9. Support to Personal Digital Assistants: Java language is compatible with Personal Java 1.1 such as chaiVM, Jeode, CrEME, and JV-Lite2 or with all the later version and it also support PDAs like HP/Compaq, iPAQ, Fujitsu-Siemens Pocket Loox and SimPad, HHP, NEC, Samsung, Sharp Electronics, Toshiba, psion m5, and any other device with Windows CE/Pocket PC 2002/2003/2005).

Versions Download Java

Major release versions of Java, along with their release dates: 

1. JDK 1.0 (January 23, 1996)
2. JDK 1.1 (February 19, 1997)
3. J2SE 1.2 (December 8, 1998)
4. J2SE 1.3 (May 8, 2000)
5. J2SE 1.4 (February 6, 2002)
6. J2SE 5.0 (September 30, 2004)
7. Java SE 6 (December 11, 2006)
8. Java SE 7 (July 28, 2011)