Introduction to Java : A Comprehensive Guide to Its Features, Editions and History

Introduction

Java is an object-oriented, platform-neutral, secure language designed by James Gosling at Sun Microsystems. It is used for building web apps, mobile applications, and enterprise software systems. Java is known for its write once, run anywhere capability. Java can be found in many places including Cloud servers, relational databases, orbiting telescopes, cell phones etc.

Java syntax and structure is similar to C-based languages like C++ and C#.

Features of Java:

1. Object-oriented language

2. Platform Independent

3. Simple and Secure

4. Multithreaded

5. Interpreted and High performance

1. Object-oriented language:

Object-Oriented Programming is a way of writing code where we create objects using classes to represent real-life things. Think of it like building houses. A class is like a blueprint that shows how the house should be built. The objects are the actual houses made from that blueprint. Each house follows the same design, but they can have their own unique features, like different colors or sizes. In the same way, objects in programming can have the same structure but different values for their properties.

• Encapsulation

• polymorphism

• inheritance

• Abstraction

• interface

In-depth about these OOP concepts later.

2. Platform Independent:

To understand how Java is platform-independent, it is important to learn how Java code is compiled and executed. When you write a Java program, it is saved as a .java file (source code). This source code is then compiled by the Java compiler (javac) into bytecode — an intermediate, non-executable, and platform-neutral code stored in a .class file.

This bytecode is not run directly by the computer. Instead, it is executed by the Java Virtual Machine (JVM), which translates the bytecode into machine-specific instructions at runtime. Because every platform (Windows, Mac, Linux, etc.) has its own JVM, the same bytecode can run on any system — making Java platform-independent.

3. Simple and secure-

• Java is simple because it has easy syntax, automatic memory management (built-in garbage collector) and rich standard libraries.

• Java is secure because it has no pointers, Sandbox Environment and bytecode verification which ensures security.

4.Multithreaded-

• Java has the ability to execute multiple threads (tasks) concurrently.

5. Interpreted and High Performance-

• Java's bytecode is interpreted into machine code enabling portability and flexibility.

• Java code is compiled to bytecode which increases speed.

Packages, Syntax and libraries:

1. Packages: Group of related files added together. This improves modularity.

2. Syntax: Rules that need to be followed when writing code in java.

3. Libraries: Collection of pre-written classes, methods that provide reusable functionality for common programming task.

First Java Code

package javateach;


import java.util.*;

public class FirstProgram { //importing a java library
    public static void main(String[] args) {// creating a class
        System.out.println("Hello World");// method that prints "Hello World"       
    }
}

Most basic code that prints Hello World as the output.

Understanding the code syntax:

In-depth explanation about these terms later

• import java.util.*: this is importing a java package.

• public: this is an access modifier which indicates that this class can be accessed from anywhere.

• class: indicates that a class is being created.

• FirstProgram: this is the name of the class and it must match the code file name. In this case, the name of the file must be FirstProgram.java.

• static: keyword that indicates this method can be accessed without need to create an object of the class. (more on this later)

• void: it is a return type that indicates no value will be returned by the method.

• System.out.println(): predefined method that is used to print values in the screen.

Java Development Kit

The Java Development Kit (JDK) is a complete toolkit that allows developers to create, compile, and run Java programs. It includes essential tools like the Java compiler (javac), which converts your source code into bytecode, and the Java Runtime Environment (JRE), which provides everything needed to run the compiled code. Inside the JRE includes the Java Virtual machine, set of java libraries and other files.

Java Product Suites:

Java Editions

Java Standard Edition (SE)-

1. • Purpose: Core Java platform used for general-purpose programming.

     • Use Cases: Desktop applications, basic server apps, and foundational Java development.

     • Features:

       • Core libraries (java.lang, java.util, etc.)

       • GUI libraries (Swing, AWT)

       • Networking, I/O, concurrency support

     • Ideal for: Beginners learning Java, desktop apps, standalone apps.

Java Enterprise Edition (EE)

1. • Purpose: Extension of Java SE for building large-scale, distributed, multi-tiered, scalable, reliable, and secure network applications.

     • Use Cases: Web applications, enterprise-level apps, microservices.

     • Features:

       • Servlets, JSP (JavaServer Pages)

       • Enterprise JavaBeans (EJB)

       • Java Message Service (JMS)

       • Web Services (REST, SOAP)

       • Dependency Injection, Persistence API (JPA)

     • Ideal for: Enterprise applications, complex web apps, cloud apps.

Java Micro Edition (ME)

1. • Purpose: Lightweight Java platform optimized for embedded systems and mobile devices with limited resources.

     • Use Cases: Mobile phones, embedded systems, IoT devices, smart cards.

     • Features:

       • Small runtime footprint

       • APIs for mobile apps and embedded devices

       • Optimized libraries for low memory/processing power

     • Ideal for: Developing apps for constrained devices like feature phones, sensors.

History of Java

• 1991: Java was created by James Gosling and his team at Sun Microsystems.

• Original Goal: To develop a programming language for consumer electronics (like TVs and microwaves) that could run on any device.

• 1995: Java was officially released to the public as Java 1.0. The key idea was “Write Once, Run Anywhere” — meaning Java programs could run on any device with a Java Virtual Machine (JVM), regardless of hardware or OS.

• Why It Became Popular: Its platform independence, security features, and robust libraries made it perfect for web applications, enterprise software, and later Android development.

• 2006: Sun Microsystems made Java open source, increasing its popularity.

• 2010: Oracle Corporation acquired Sun Microsystems and took over Java’s development.

• Today: Java remains one of the most widely used programming languages worldwide, powering everything from mobile apps and web servers to big data platforms and enterprise systems.