DAY Dec19

What is Java technology ?
1. Java is a programming language and computing platform first released by Sun Microsystems in 1995. It has evolved from humble beginnings to power a large share of today’s digital world, by providing the reliable platform upon which many services and applications are built.

2.Java is a high-level, class-based, object-oriented programming language that is designed to have as few implementation dependencies as possible. It is a general-purpose programming language intended to let programmers write once, run anywhere (WORA), meaning that compiled Java code can run on all platforms that support Java without the need to recompile.

3.Java is a widely-used programming language for coding web applications. It has been a popular choice among developers for over two decades, with millions of Java applications in use today. Java is a multi-platform, object-oriented, and network-centric language that can be used as a platform in itself.

History Of Java :
---> Java was originally developed by James Gosling at Sun Microsystems. It was released in May 1995 as a core component of Sun's Java platform.
---> The original and reference implementation Java compilers, virtual machines, and class libraries were originally released by Sun under proprietary licenses.
---> Oracle offers its own HotSpot Java Virtual Machine, however the official reference implementation is the OpenJDK JVM which is free open-source software and used by most developers ands the default JVM for almost all Linux distributions.
---> As of September 2024, Java 23 is the latest version (Java 22, and 20 are no longer maintained). Java 8, 11, 17, and 21 are previous LTS versions still officially supported.

Use outside the Java platform:
---> The Java programming language requires the presence of a software platform in order for compiled programs to be executed.
----> Oracle supplies the Java platform for use with Java. The Android SDK is an alternative software platform, used primarily for developing Android applications with its own GUI system.

Android :
---> The Java language is a key pillar in Android, an open source mobile operating system. Although Android, built on the Linux kernel, is written largely in C, the Android SDK uses the Java language as the basis for Android applications but does not use any of its standard GUI, SE, ME or other established Java standards.

---> The bytecode language supported by the Android SDK is incompatible with Java bytecode and runs on its own virtual machine, optimized for low-memory devices such as smartphones and tablet computers. Depending on the Android version, the bytecode is either interpreted by the Dalvik virtual machine or compiled into native code by the Android Runtime.
---> Android does not provide the full Java SE standard library, although the Android SDK does include an independent implementation of a large subset of it.

Why do we need Java?
Because
* Java is an object oriented programming language.
* Java is a plateform independent language.
* Java is secure.
* Java is robustness.
* Java is portable.
* Java is interpreted, threaded and dynamic.
* Scalability and Reliability.
* Widely used development languages.
* Easy to use.
* Transition to other languages would be easier.
* Java is multiparadigm programming language.
etc...

Reference:
1.https://en.wikipedia.org/wiki/Java_(programming_language)
2.https://www.java.com/en/download/help/ whatis_java.html#:~:text=Java is a programming language,patch each quarter when prompted?
3.https://www.w3schools.com/java/java_intro.asp

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