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Java Primer

 

 

 

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Java Origin:

Java is a programming language originally developed by James Gosling at Sun Microsystems and released in 1995. The language derives much of its syntax from C and C++ but has a simpler object model. Java applications are typically compiled to bytecode (class files) that can run on any Java virtual machine (JVM) regardless of computer architecture or operating system. As of May 2007, in compliance with the specifications of the Java Community Process, Sun made available most of their Java technologies as free software under the GNU General Public License (GNU GPL or simply GPL is a widely used free software license).

It was originally designed for use on digital mobile devices, such as cell phones. However, when Java 1.0 was released to the public in 1996, its main focus had shifted to use on the Internet. It provided more interactivity with users by giving developers a way to produce animated webpages . Over the years it has evolved as a successful language for use both on and off the Internet. A decade later, it’s still an extremely popular language with over 6.5million developers worldwide.

There were five primary goals in the creation of the Java language:

  • It should be “simple, object oriented, and familiar”.
  • It should be “robust and secure”.
  • It should be “architecture neutral and portable”.
  • It should execute with “high performance”.
  • It should be “interpreted, threaded, and dynamic”.

 

Java Introduction:

 “Java” generally refers to a combination of three things: the Java programming language (a high-level, object-oriented programming language); the Java Virtual Machine (a high-performance virtual machine that executes bytecodes on a specific computing platform, typically abbreviated JVM); and the Java platform, a JVM running compiled Java bytecodes, usually calling on a set of standard libraries such as those provided by Java Standard Edition (SE) or Enterprise Edition (EE).

For every dusty definition that speaks of applets and Just-In-Time compilers, there are new directions and new realities that have settled in, understood by many, yet not always completely documented. Java used to mean:

  • Applets
  • Bytecode interpretation
  • Slow performance
  • A “cargo cult” awaiting drops from Sun

Today, it means:

  • Web applications, web services, SOAs, etc.
  • Hotspot dynamic compilation
  • High-performance
  • An open source community, increasingly independent of Sun

The old slogan “Write Once, Run Anywhere” still holds true–but what’s being written and where and how it’s being run are changing.

  

Implementations: Read more…

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