Java Introduction

• Java is a :-
  1. Programming Language :
     • Java is a high-level, object-oriented programming language that enables developers to write instructions for execution.
     • For example "teacher" who gives the instructions to students to perform specific tasks, developers use Java to instruct the system to execute desired operations like addition, subtraction, division, login, register, add items into cart, online payment etc.
     • Developers can use Java to perform various tasks such as addition, subtraction, user authentication (login and registration), adding items to a cart, or processing online payments.
     • It is designed to be simple, object-oriented, and user-friendly, similar to languages like C and C++.
  2. Platform :
     • Java is a platform that provides a robust environment, or "stage," where developers can execute Java code. This platform ensures all necessary tools and libraries are available for the code to run smoothly.
     • For example "stage in a theater" provides the setup for actors to perform their roles, Java provides the environment where we can write, run and manage Java programs easily.

• 

  Java was originally developed by James Gosling and his team of engineers at Sun Microsystems. Its development was started in June 1991 and first public version was released in 1996. In 2010, Oracle Corporation acquired Sun Microsystems, which made Oracle the owner of Java and its associated technologies. Since then, Oracle has been responsible for maintaining and advancing the Java platform.
• The original name of Java was "Oak". James Gosling and his team initially named it after an oak tree that stood outside Gosling's office at Sun Microsystems. However, the name was later changed to Java in 1995 due to trademark issues. The name "Java" was inspired by the Java coffee from Indonesia, as coffee was considered a metaphor for energy and vitality.
• Java code is written in human-readable form and saved with a .java file extension. This code is then compiled into bytecode by the Java compiler (javac), which is a lower-level, platform-neutral representation of the code. This bytecode is later executed by the Java Virtual Machine (JVM).

Java Program Example

public class MainApp
{
    public static void main(String[] args)
    {
        System.out.println("Hello, World!");
    }
}

Types of Java Edition

There are total 5 editions in Java which are as below :-
   1. Java Standard Edition (Java SE)
   2. Java Enterprise Edition (Java EE)
   3. Java Micro Edition (Java ME)
   4. JavaFX
   5. Java Card

These are explained deeply in below....

• 1. Java Standard Edition (Java SE)

  Introduction : Java SE is the core edition of the Java platform and provides the foundational APIs and tools for general-purpose programming. It includes basic libraries for data structures, networking, I/O, and more.

  Applications :

  • Desktop Applications : Java SE is used to create standalone desktop applications, such as productivity software, utilities, and games. Examples include IDEs like IntelliJ IDEA and software like Eclipse.
  • Command-Line Tools : Java SE is also used for developing command-line tools and utilities that run on various operating systems.
  • Small-to-Medium Size Application : Java SE is suitable for developing smaller-scale applications that don’t require the extensive features of Java EE.

• 2. Java Enterprise Edition (Java EE)

  Introduction : Java EE (now Jakarta EE) is designed for large-scale, distributed, and multi-tiered applications. It extends Java SE with additional libraries and APIs for enterprise-level development, including web services, component-based architecture, and database interaction.

  Applications :

  • Web Applications : Java EE is used to build robust web applications using technologies like Servlets, JSP (JavaServer Pages), and JSF (JavaServer Faces). It supports frameworks like Spring and Hibernate.
  • Enterprise Applications : Java EE is ideal for developing complex, scalable enterprise systems like ERP (Enterprise Resource Planning) and CRM (Customer Relationship Management) systems.
  • Web Services : Java EE supports the development of RESTful and SOAP-based web services that allow different systems to communicate over the web.
  • E-Commerce Systems : Java EE is widely used to create large e-commerce platforms that require high availability, scalability, and security.

  Note: Java EE has been rebranded as Jakarta EE under the Eclipse Foundation. The shift is more about the organization managing the technology rather than the technology itself.

• 3. Java Micro Edition (Java ME)

  Introduction : Java ME is a subset of Java SE designed for developing applications on resource-constrained devices like embedded systems, mobile phones, and IoT (Internet of Things) devices.

  Applications :

  • Mobile Applications : Before the rise of Android, Java ME was the primary platform for developing mobile applications for feature phones and early smartphones.
  • Embedded Systems : Java ME is used in embedded devices such as smart cards, GPS devices, and home automation systems.
  • IoT Applications : Java ME provides a lightweight platform for IoT devices, enabling the development of applications that run on small, connected devices with limited processing power and memory.

• 4. JavaFX

  Introduction : JavaFX is a platform for building rich internet applications (RIAs) that can run on various devices. It provides a modern, hardware-accelerated user interface and is often used for creating visually appealing desktop applications.

  Applications :

  • Rich Internet Applications (RIAs) : JavaFX is used to create interactive, visually rich applications that can run on the desktop, web, or embedded devices.
  • Multimedia Applications : JavaFX is suitable for developing applications that require advanced graphics, media playback, and complex animations.
  • Data Visualization Tools : JavaFX is often used in building tools that visualize complex data, such as charts, graphs, and simulations.

• 5. Java Card

  Introduction : Java Card is a specialized edition of the Java platform designed for secure, resource-constrained environments like smart cards and SIM cards. It enables small applications (applets) to run securely on devices with minimal memory and processing power, commonly used in industries requiring high security, such as banking, telecommunications, and government ID systems.

  Applications :

  • Smart Cards: Java Card is used in the development of applications for smart cards, including payment cards (credit/debit), identification cards, and access control systems. The technology enables secure storage of sensitive data like cryptographic keys and personal identification information.
  • SIM Cards: Java Card powers SIM cards used in mobile phones. It allows telecom providers to securely manage and store subscriber information, including authentication keys and contact information. It also enables Over-the-Air (OTA) updates of applets and services on SIM cards.
  • Secure Authentication: Java Card is used in devices that require strong authentication, such as hardware security tokens (e.g., for two-factor authentication), digital signatures, and encryption devices. The small, secure environment of Java Card makes it ideal for cryptographic operations and secure transaction processing.
  • Contactless Payment Systems: Java Card is commonly employed in contactless payment systems such as NFC-based payment cards and mobile payment solutions. Its secure and lightweight environment ensures the protection of financial transactions.
  • ePassports and ID Cards: Governments use Java Card technology to power ePassports and national ID cards. These cards securely store and manage biometric data and personal identification details to ensure security and privacy in identification and travel systems.