Lesson 2 - Introduction to Java

Why Java

“Java powers over 3 billion devices worldwide,” according to Oracle. That’s not just a statistic—it’s proof of how deeply this programming language shapes the technology we use daily. From banking apps to Android phones, Java is there, quietly making things work.

Learning Java isn’t just about syntax. It’s about mastering a skill that is portable, scalable, and trusted by some of the biggest tech companies in the world. Whether your goal is to build mobile apps, enterprise software, or cloud solutions, Java gives you a foundation that’s relevant and in demand.

Why Learn Java

• Widely Used – Runs on over 3 billion devices worldwide.
• Strong Career Potential – In-demand for enterprise, mobile, and cloud-based applications.
• Cross-Platform Development – One codebase works on multiple operating systems.
• Foundation for Other Languages – Teaches object-oriented concepts used in C#, Python, Kotlin, and more.
• Trusted by Industry Leaders – Used by companies like Google, Accenture, and Intel.
• Long-Term Relevance – Over two decades old and still actively developed.
• Rich Ecosystem – Access to powerful libraries, frameworks, and tools.
• Scalable – Suitable for small apps and large enterprise systems.
• Stable and Secure – Designed to minimise security risks and ensure reliability.

What is Java

Java is a high-level, object-oriented programming language designed to run on multiple platforms without modification. This is possible because of the Java Virtual Machine (JVM), which executes Java programs on any device or operating system.

• High-level – Closer to human language than machine code, making it easier to write and understand.
• Object-oriented – Organises code into objects that hold both data (attributes) and behaviours (methods).
• Platform-independent – Write the code once, run it anywhere with Java support.

Analogy: Think of Java as a universal charger—you can plug it in anywhere, and it works without needing a different version for each device.

History of Java

Java was developed in the early 1990s by James Gosling and his team at Sun Microsystems, known as the Green Team. Initially intended for interactive television—like live voting during a TV show—the technology was too advanced for the market at the time but found its ideal match in the growing World Wide Web.

Key Milestones:

• Initially called Green Talk, then Oak in 1994.
• Official release as Java 1.0 in 1995.
• 2006 – JVM made open source; J2SE renamed Java Standard Edition (Java SE).
• Major releases – Java SE 6 (2006), Java SE 8 (2014). Java 8 and Java 11 are Long-Term Support (LTS) versions.
• Since 2007, Java has been managed through the Java Community Process (JCP).

Impact:

Java powers frameworks and tools like JUnit, Eclipse, Hadoop, and Android. It’s used by companies such as Google, Accenture, Intel, and Philips. It is also the official language for Android development, even in popular games like PUBG.

Features of Java

Java’s features make it one of the most versatile programming languages in existence:

• Simple – Easier to learn compared to older languages, with a clean syntax and no pointer complexity.
• Object-Oriented – Encourages code reuse and modular design.
• Platform-Independent – JVM ensures “Write Once, Run Anywhere.”
• Secure – Built-in safeguards protect against unauthorised access.
• Robust – Strong memory management and exception handling.
• Multithreaded – Handles multiple tasks at the same time.
• High Performance – JIT compiler boosts execution speed.
• Distributed – Supports network-based applications.
• Modern Enhancements (Java 8–21) – Lambda expressions, Streams API, var keyword, Pattern Matching, Record classes, and Virtual Threads for scalable concurrency.

Conclusion

Java has stood the test of time because it adapts while staying true to its core principles. It is as relevant in mobile app development as it is in enterprise and cloud computing. For students, learning Java means gaining skills that transfer to many other languages and platforms.

Call to Action

Start small. Install Java on your computer and write your first program today. Practice regularly, explore Java’s object-oriented features, and experiment with real-world projects. The sooner you begin coding in Java, the sooner you’ll understand why it remains one of the most trusted tools in the world of programming.