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Java is a programming language and computing platform first released by Sun Microsystems in 1995 by James Gosling. There are lots of applications and websites that will not work unless you have Java installed, and more are created every day.The latest Java version contains important enhancements to improve performance, stability and security of the Java applications that run on your machine. Installing this free update will ensure that your Java applications continue to run safely and efficiently.

what is java

Java is a programming language and a platform.
Java is a high level, robust, secured and object-oriented programming language.
Platform: Any hardware or software environment in which a program runs, is known as a platform. Since Java has its own runtime environment (JRE) and API, it is called platform.
java example:
A detailed description of hello Java example is given in next page.
class Simple {  
public static void main(String args[]) {  
System.out.println("Hello Java");  

Where it is used?

According to Sun, 3 billion devices run java. There are many devices where Java is currently used. Some of them are as follows:
  • Desktop Applications such as acrobat reader, media player, antivirus etc.
  • Web Applications such as, etc.
  • Enterprise Applications such as banking applications.
  • Mobile
  • Embedded System
  • Smart Card
  • Robotics
  • Games etc.
  • Types of Java Applications

    There are mainly 4 types of applications that can be created using java programming:
    1. Standalone Application
    2. Web Application
    3. Enterprise Application
    4. Mobile Application

    Java Platforms / Editions

    There are 4 platforms or editions of Java:
    1. Java SE (Java Standard Edition)
    2. Java EE (Java Enterprise Edition)
    3. Java ME (Java Micro Edition)
    4. JavaFx

    Java Version History

    There are many java versions that has been released. Current stable release of Java is Java SE 8.
  • JDK Alpha and Beta (1995)
  • JDK 1.0 (23rd Jan, 1996)
  • JDK 1.1 (19th Feb, 1997)
  • J2SE 1.2 (8th Dec, 1998)
  • J2SE 1.3 (8th May, 2000)
  • J2SE 1.4 (6th Feb, 2002)
  • J2SE 5.0 (30th Sep, 2004)
  • Java SE 6 (11th Dec, 2006)
  • Java SE 7 (28th July, 2011)
  • Java SE 8 (18th March, 2014)
  • Features of Java

    There is given many features of java. They are also known as java buzzwords. The Java Features given below are simple and easy to understand.

  • Simple
  • Object-Oriented
  • Portable
  • Platform independent
  • Secured
  • Robust
  • Architecture neutral
  • Dynamic
  • Interpreted
  • High Performance
  • Multithreaded
  • Distributed
  • Simple
    According to Sun, Java language is simple because:
    syntax is based on C++ (so easier for programmers to learn it after C++).
    removed many confusing and/or rarely-used features e.g., explicit pointers, operator overloading etc.
    No need to remove unreferenced objects because there is Automatic Garbage Collection in java.
    Object-oriented means we organize our software as a combination of different types of objects that incorporates both data and behaviour.
    Basic concepts of OOPs are:
  • Object
  • Class
  • Inheritance
  • Polymorphism
  • Abstraction
  • Encapsulation
  • Platform Independent
    A platform is the hardware or software environment in which a program runs.
    There are two types of platforms software-based and hardware-based. Java provides software-based platform.
    It has two components:
    Runtime Environment
    API(Application Programming Interface)
    No explicit pointer
    Java Programs run inside virtual machine sandbox
    Robust simply means strong. Java uses strong memory management. There are lack of pointers that avoids security problem. There is automatic garbage collection in java. There is exception handling and type checking mechanism in java. All these points makes java robust.
    There is no implementation dependent features e.g. size of primitive types is fixed.
    In C programming, int data type occupies 2 bytes of memory for 32-bit architecture and 4 bytes of memory for 64-bit architecture. But in java, it occupies 4 bytes of memory for both 32 and 64 bit architectures.
    We may carry the java bytecode to any platform. nd type checking mechanism in java. All these points makes java robust.
    Java is faster than traditional interpretation since byte code is "close" to native code still somewhat slower than a compiled language.
    We can create distributed applications in java. RMI and EJB are used for creating distributed applications.
    A thread is like a separate program, executing concurrently.