Why Java is More Popular:
- Java is a open source programming language created by Sun Microsystems.
- Java is platform independent language means you can run Java Program on any
platform(OS + Processor).
- Java is fast because of JIT compiler.
- Java provide Garbage collector so it take care of memory.
- Java is robust and Secure.
- It is interpreted, Multithreaded and Dynamic.
Versions of Java
- JDK 1.0 January 23, 1996)
- JDK 1.1 (February 19, 1997)
- J2SE 1.2 (December 8, 1998)
- J2SE 1.3 (May 8, 2000)
- J2SE 1.4 (February 6, 2002)
- J2SE 5.0 (September 30, 2004)
- Java SE 6 (December 11, 2006)
- Java SE 7 (July 28, 2011)
- Java SE 8 (March 18, 2014) Source: Wikipedia
- When you compile a java program java compiler,it will convert java source file into byte code and extension of byte code is .class.
- A .class file is JRE dependent but independent of Platform(OS + Hardware). Because a separate JRE is developed for each OS.
What is JIT compiler ?
- JIT means just in time Compiler.
- Just in time compilation is compilation done during execution of a program
at run time rather than prior to execution.
- It is also known as Dynamic Translation.
- JIT is a program that turns java byte code into instruction that can be sent
directly to the processor.
Parts of Java Language:
As per Sun micro system java is divided into three types:
- J2SE/JSE (java 2 standard edition)
- J2EE/JEE (java 2 enterprise edition)
- J2ME/JME (java 2 micro edition)
J2SE :- It is basically used to develop standalone applications.
Eg:- Notepad, Paint, Media Player.
Standalone Applications :-
- It is installed on a system and run without any client server architecture.
- It is also called as desktop application or window application.
J2EE :- It is used to develop web based applications like gmail, Facebook, any kind of other websites and tool which runs on the internet.
- Web-Application runs on internet.
- Hence they need to have a client server architecture.
- It can be launched by using HTTP request/response.