Java - Introduction


Java - Introduction

What is Java?

  • Java is a high-level object oriented programming language at the developed by Sun Microsystems. 

History of Java :

  • Initially originated by James Gosling in the year 1991, but took to shape and was released in 1995. The current release of the Java standard edition is Java SE 8. Since Java is assured to be Write once, Run anywhere it gained popularity and hence paved way for varieties such as J2EE for corporation applications, J2ME for cellular programs.
Java code compile/execute Processes :


  • Java code is created with normal text editor and saved with extension “.java”.
  • It is then sent to Java Compiler, which then produces a byte code with the extension “.class”.
  • Then the Java Virtual Machine executes the class file, that is bye code to produce results.

Java version Information :


  • Java was introduced initially with Java Development Kit 1.0.
  • JDK faced version updates and then came Java Standard Edition, termed as J2SE with advanced features.
  • Recent edition, Java SE 8 for Java encloses much more new features, improvements and bug fixes to progress competence to create and run Java programs.

Prerequisites :

  1. Operating System such as Linux or Windows.
  2. Java JDK.
  3. Text editor.

Suggested Text Editors :

  • Notepad: Suggested easy and simple text editor mostly suitable for Windows OS.
  • NetBeans: It is one of the best editors for Java, is totally modularized, and offers easy integration with version manage software program. Available for download @ NetBeans.
  • Eclipse: One another popular editor for Java and is an open source tool with variety of plug-in, created by users.Available for download @ Eclipse.

Features of Java :

Platform Independent :

  • Java runs on a spread of systems, together with windows, Mac OS, and the various variations of UNIX and hence termed as platform independent. 

Secure :

  • Java's authentication techniques allow creating secure applications as these techniques are primarily laid on public-key encryption standards.

Source :

  • Java syntax borrows closely from C and C++ however it removes positive low-degree constructs together with hints and has a completely easy memory model in which each item is allocated at the heap and all variables of object sorts are references. 

Robust :

  • Java eradicates errors by highlighting checks particularly on compile time errors and runtime errors.

Multithreaded :

  • Java's multithreaded feature enables programs to do many tasks concurrently thus allowing being highly interactive.

Interpreted :

  • Java byte code is converted to native system instructions and isn't saved anywhere. The procedure is very rapid and analytical for the reason that linking is an incremental and light weight methodology.

Distributed :

  • Java is basically designed for the distributed internet environment.

Dynamic :

  • java environment is considered to be more dynamic than C or C++ due to the fact its miles designed to conform to an evolving surroundings. Java programs can bring significant amount of run-time statistics that may be used to verify and clear up accesses to gadgets on run-time.

Memory management :

  • Memory management is attained via automatic garbage series achieved by the Java virtual machine (JVM). Java Interpreter appears to be a part of the JVM as shown below.

Java virtual machine :


Performance :

  • Just-In-Time compiler enables java runtime environment to attain a high overall performance.

Java Program Flow :

Java program flow from creation to execution is depicted below:

  • Source code saved in editor -> Java Compiler (JDK) -> Java Bye Code -> Just-In-Time Compiler -> Executed on Java Run-time Environment -> OUTPUT.