What Is Java
Java Introduction
Java is a General Purpose and Object Oriented programming language created by James Gosling from Sun Microsystems in 1991. The first publicly released of Java (Java 1.0) in 1995. Java is Based on "write once, run anywhere" (WORA) Feature, meaning that code that runs on one platform does not need to be recompiled to run on another. Java Programs are compiled to bytecode (.class file) that can run on any Java virtual machine (JVM) regardless of computer architecture.
- Java is one of the slang terms for coffee
- Todays six million+ Java developers are one of the largest communities of software developers.
- Java software runs on more types of consumer and embedded devices, smart cards, ATMs, thin clients, PCs, servers, and mainframes than any other software.
- The Java economy includes 2.5 billion+ smart cards, 800 million+ PCs shipped with Java, 1.85+ billion Java Powered phones, and over 180+ telecom providers who deploy Java technology-based content/services.
What is Java
Java is a programming language that produces software for multiple platforms. When a programmer writes a Java application, the compiled code (known as bytecode) runs on most operating systems (OS), including Windows, Linux, and Mac OS. Java derives much of its syntax from the C and C++ programming languages.
- Java is a programming language and a platform.
- Java is a high level, robust, secured and object-oriented programming language.
- Platform: Any hardware or software environment in which a program runs, is known as a platform. Since Java has its own runtime environment (JRE) and API, it is called platform.
Java Example
Let's have a quick look at java programming example. A detailed description of hello Java example is given in the next page.
class FirstExample{
public static void main(String args[]){
System.out.println("Welcome To java");
}
}
Where it is used?
According to Sun, 3 billion devices run java. There are many devices where java is currently used. Some of them are as follows:
- Desktop Applications such as acrobat reader, media player, antivirus, etc.
- Web Applications such as irctc.co.in, javatpoint.com, etc.
- Enterprise Applications such as banking applications.
- Mobile
- Embedded System
- Smart Card
- Robotics
- Games etc.
Types of Java Applications
There are mainly 4 types of applications that can be created using java programming:
Standalone Application :
It is also known as a desktop application or window-based application. An application that we need to install on every machine such as media player, antivirus, etc. AWT and Swing are used in java for creating standalone applications.
Web Application :
An application that runs on the server-side and creates a dynamic page, is called web application. Currently, servlet, JSP, struts, JSF, etc. technologies are used for creating web applications in java.
Enterprise Application
An application that is distributed in nature, such as banking applications, etc. It has the advantage of high-level security, load balancing, and clustering. In java, EJB is used for creating enterprise applications.
Mobile Application
An application that is created for mobile devices. Currently, Android and Java ME are used for creating mobile applications.
Java Platforms / Editions
There are 4 platforms or editions of Java:
Java SE (Java Standard Edition) :
It is a java programming platform. It includes Java programming APIs such as java.lang, java.io, java.net, java.util, java.sql, java.math etc. It includes core topics like OOPs, String, Regex, Exception, Inner classes, Multithreading, I/O Stream, Networking, AWT, Swing, Reflection, Collection, etc.
Java EE (Java Enterprise Edition)
It is an enterprise platform that is mainly used to develop web and enterprise applications. It is built on the top of the Java SE platform. It includes topics like Servlet, JSP, Web Services, EJB, JPA, etc.
Java ME (Java Micro Edition)
It is a micro platform which is mainly used to develop mobile applications.
JavaFX
It is used to develop rich internet applications. It uses a light-weight user interface API.
