Java

Description #

Java is a powerful, object-oriented programming language designed for cross-platform compatibility, scalability, and security. Known for its “write once, run anywhere” (WORA) principle, Java is used in web applications, Android development, enterprise systems, and large-scale backend infrastructures.

History #

Java was developed by James Gosling and his team at Sun Microsystems in the early 1990s. Originally called Oak, it was renamed Java in 1995 after discovering the name Oak was already trademarked. The language quickly became popular due to its simplicity, robustness, and platform independence powered by the Java Virtual Machine (JVM).

Key milestones in Java’s evolution include:

• Java 1.0 (1996) – first public release
• Java 2 (1998) – added Swing, Collections Framework
• Java 5 (2004) – introduced generics, enums, annotations
• Java 8 (2014) – added lambda expressions and streams
• Java 17 (2021) – current LTS (Long-Term Support) version as of now

After Oracle acquired Sun Microsystems in 2010, Java’s stewardship shifted, and today it is maintained by Oracle and the OpenJDK community.

Hello World Code #

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

How to Run #

Save the file as HelloWorld.java (must match the class name)

Compile the file using:

javac HelloWorld.java

Run the compiled class:

java HelloWorld

📝 Make sure Java is installed and configured in your system PATH.

Key Concepts #

public class — defines the class structure

main() — entry point for execution

System.out.println() — prints output to the console

Strongly typed — variables must be declared with types

Object-oriented — uses classes, inheritance, encapsulation

Compiles to bytecode — runs on the JVM

Cross-platform — WORA via JVM

Garbage collection — automatic memory management

Static typing — helps catch errors at compile time

Exception handling — robust try-catch error control

Try It Online #

🔗 JDoodle – Java Compiler
🔗 Replit – Java
🔗 OneCompiler – Java

Fun Facts #

The name “Java” came from coffee beans from Java Island

Android apps were originally written in Java

Java is used by NASA, Netflix, Uber, and major banks

The Java mascot is a steaming coffee cup named “Duke”

Java powers over 3 billion devices worldwide

Resources #

Official Java Docs

Java Tutorials – Oracle

Java Programming – W3Schools

OpenJDK Project