Due to platform independent nature, java widely used in various categories of devices. There are many security features in java, we will understand them latter. Day by day java is getting more flexible, it has ability to adopt the changes so in this way java is always a demanded language.
Java Today
- Java is related to C++.
- Java’s syntax is derived from C language
- Java was really a response to its predecessors, they change for the better.
- Java was built to solve a problem that before couldn’t be solved.
- Java is “ write once run anywhere"
Java Programming Language
Java is called as general purpose programming language.
General Purpose Programming Language
The programming language which is not designed for single purpose, in other words the programming language which is designed for multiple purposes is called as general purpose programming language.
Scope of Java Language
Java language can be used in hardware industry as well as software industry.
Hardware Industry
In H/W industries java language is used to run electronics appliances like refrigerator, AC, Washing machine etc.
Software Industry
In software industries it is used to design and develop software application or web application for example Banking Software, calculator, notepad, web applications etc.
Note: Java is also called as WORA means write once run anywhere.
3 Editions of Java
- J2SE: Java 2 Standard Edition ( Core Java, JBC ) used for develop standalone application / Desktop application
- J2EE: Java 2 Enterprise Edition ( JSP, Servlet, Framework ) used for develop dynamic Application / Web Application ( static, dynamic )
- J2ME: Java 2 Micro Edition ( Android ) used for develop mobile application
With the help of java two types of application can be developed:
- Standalone application
- Dynamic / Web application
Standalone Application
Those applications which don’t require any external resource is called as standalone application for example calculator, notepad, paint, clock, word pad etc. these are standalone applications.
Dynamic / Web application
Those applications which required or depend on any external resource are called as Dynamic / Web Application. For example Social media like Facebook, YouTube, Twitter, Google search engine etc.
External Resources
Things that are not part of that machine on which program or application are running for example Internet, Network, Database, server etc.
Platform Independent
There are two most important components to execute any java program:
- JDK: Java Development Kit
- JRE: Java runtime environment (JVM)
Coading ---→ Compilation ( JDK ) ---→ Execution ( JRE )
JDK: Java Development Kit
JDK is responsible for compilation of java source code and after compilation it generates .class file, this .class file is in the form of byte code and it can be run on any operating system, Because of this java is called as platform independent.
JRE: Java runtime environment ( JVM )
JER provide environment to execute .class file and provide output, JVM is the most impotant component of JRE.