本文探讨了Java作为一种编程语言的独特魅力及其在软件开发领域的战略地位。文章回顾了Java的起源和发展历程，从最初的“一次编写，随处运行”的承诺，到如今在企业级应用、移动应用以及AI领域的广泛应用。同时，文章还介绍了Java 23带来的新特性，例如简化了语言的入门门槛，并增强了模式匹配和记录类的功能，使其更适应现代开发的需求。此外，文章还以Minecraft为例，展示了Java在游戏开发领域的应用，以及其强大的生态系统对现代创新的重要支撑作用。

🚀 Java的核心优势在于其“一次编写，随处运行”的特性，这得益于Java虚拟机（JVM）的存在，使得Java代码可以在任何支持Java平台的设备上运行，无需为每个操作系统重新编译。

✨ Java 23通过简化语言的入门方式，降低了新手开发者的学习门槛。例如，经典的“Hello, World!”程序被简化到只有几行代码，避免了初学者一开始就被复杂的概念所困扰。

🧩 Java生态系统拥有强大的Java类库（JCL），为开发者提供了丰富的工具和资源。无论是构建欺诈检测算法还是推荐引擎，开发者都可以依赖JCL，从而提高开发效率和代码质量。

🎮 Minecraft的成功证明了Java在不同领域的适用性。游戏引擎利用Java的面向对象架构来管理无数的方块，这与企业系统处理大量业务对象或AI应用处理海量数据集的方式类似。

Here’s a true story: I learned Java after pretending to be an Android developer when I first started out in software development. While doing that, I quickly learned something important: Java isn’t just a convenient entry point into tech, it’s a strategic career choice.

That’s why I want to examine what makes Java so interesting—and how you can either get started or brush up on your skills. After all, when you are trying to break into tech, especially when you’re coming from a non-traditional background like me (I began my career as an Army soldier and construction manager), you need a language that’s both learnable and employable. And, in my experience, knowing your way around Java opens doors that might otherwise stay closed to a newcomer.

So, let’s jump in.

What is Java? And what’s the difference between Java and JavaScript?

When we think about the programming languages that form the backbone of enterprise software development, Java is one of the first names that comes to mind. At its core, Java is a versatile, object-oriented programming language, rooted in its “write once, run anywhere” (WORA) strength. Thanks to the Java Virtual Machine (JVM), it powers the foundation for scalable, secure applications across nearly every industry.

Despite sharing part of its name with JavaScript, Java serves a distinctly different purpose. JavaScript is a lightweight language used predominantly for front-end web development, backend work, and full-stack applications. Meanwhile, Java is a general purpose language that is used for everything from backend development to desktop applications, mobile apps, and large-scale enterprise applications.

Today, Java powers everything from your Spotify playlist in Android mobile to the Cash App transaction to split your dinner check. In short, Java powers massive systems that process millions of data transactions every day.

And let’s clear something up: if you’re picturing verbose enterprise code running on dusty servers, it’s time for an update. Java has evolved from its enterprise roots, where it was largely used for powering payroll systems and customer databases, into a versatile platform driving everything from backend services to gaming to AI-powered applications such as Netflix and LinkedIn.

With a history spanning three decades, Java has proven itself as a reliable, versatile, and constantly evolving language that continues to be a top choice for developers around the world.

So, what is it about Java that has not only endured but thrived in an environment full of constant change?

To understand this resilience and versatility, let’s take a step back and look at where Java came from and how it has grown over the years.

The birth of Java: write once, run anywhere

Java’s story begins back in 1991 when a team of engineers at Sun Microsystems, led by James Gosling, set out to create a language for interactive television. First developed under the name Oak, the language that would be renamed Java was designed to be simple, robust, and platform independent, using a virtual machine—later called a Java Virtual Machine, or JVM—to run code anywhere.

While that original project didn’t quite pan out, it laid the groundwork for something much bigger.

In 1995, Java 1.0 was officially released, and with it came a revolutionary promise: “Write Once, Run Anywhere” (WORA). This principle meant Java code could be written once and then run on any device that supports the Java platform, without needing to be recompiled for each operating system.

To fully appreciate the impact of this shift, it’s helpful to look back at the state of software development in the mid ‘90s.

If you were a developer back then and you wanted your application to run on multiple operating systems (Windows, Mac, and Unix), you needed to write separate versions for each one. This meant learning the unique APIs, libraries, and quirks of each operating system—which was even more fun then than it is now (seriously, it was a slog). Updating and fixing had to be done platform by platform in a tedious grind like a messy game of Whac-A-Mole. One fix here, another patch there, and plenty of ways for things to go wrong.

This fragmented approach was a significant barrier to building software for a wide, diverse audience. For enterprises looking to deploy applications across multiple environments, Java became an incredibly attractive choice. With the emergence of enterprise-focused frameworks like J2EE and Spring, coupled with strong corporate backing from Sun Microsystems and later Oracle, it provided the reliability and consistency that businesses needed.

From complex to clear: Java’s evolution for new developers

After 30 years, you might just say that Java has come a long way from its early days.

Let’s take the release of Java 23 in September 2024 as an example. This update brought a host of new features and enhancements designed to make developers’ lives easier while keeping Java aligned with the needs of modern development. This included enhancements such as:

Primitive types in patterns, instanceof, and switch (Preview - JEP 455), which allows primitive types like int and double to be used seamlessly with pattern matching and switch statements, simplifying code and reducing workarounds

Markdown documentation comments (JEP 467), which lets developers write Java Docs using Markdown syntax to create more readable documentation directly in the source code

One of the most notable changes was the simplification of the language’s entry point for new developers. The classic “Hello, World!” program, which is often the first thing a developer writes when learning a new language, was streamlined to just a few lines of code. The traditional version required understanding several complex concepts right from the start.

Need proof? Here’s the old way:

public class HelloWorld {    // A class declaration that must match the file name    public static void main(String[] args) {    // The program's entry point        System.out.println("Hello, World!");    // The actual operation we want    }}

Each line introduced multiple new concepts—public classes, static methods, command-line arguments—before achieving the simple goal of just displaying some text.

In contrast, Java 23 streamlines the syntax to its essential requirements:

void main() {    System.out.println("Hello, World!");}

Now, you might be thinking, “That’s not a big change!” But think about it from a beginner’s perspective. When you’re just starting out with programming, even small bits of boilerplate code can be confusing and overwhelming. You’re trying to understand new concepts and syntax, and every extra line of code is one more thing to decipher.

But Java isn’t just for beginners. Java 23, for instance, brings powerful new features for more advanced uses, such as improved pattern matching and the evolution of record classes.

With the evolution of record classes, Java facilitates the implementation of modern design patterns by providing concise and immutable data structures like lists or sets. These collections can’t be changed once created, which means there are no accidental edits. This makes them ideal for building scalable microservices or event-driven architectures, where data integrity and consistency are essential.

On the other hand, the enhanced pattern matching supports primitive types, streamlining complex data handling while boosting performance by eliminating boxing overhead. This is especially critical for high-performance systems, such as financial platforms or data pipelines, where efficiency is not only key but required. Put another way, it’s the difference between a system that thrives under pressure and one that buckles.

Here’s an example of how pattern matching has been enhanced in Java 23:

switch (value) {    case int i when i > 0 -> "Positive";    case int i when i < 0 -> "Negative";    case int i when i == 0 -> "Zero";    default -> "Not a number";}

In this switch expression, the code checks both the type of the value and its specific value in one go. In older versions of Java, we had to use a series of if-else statements or a switch statement with multiple cases for each condition. But with this new syntax, the intent of the code is clear, and the logic is neatly encapsulated.

The Java ecosystem: Building blocks for modern innovation

It’s hard to talk about Java’s impact on modern software development without turning to Minecraft, one of the world’s most successful video games with over 10 million players worldwide, which was originally built entirely in Java. While Java is often associated with enterprise computing, the original Minecraft: Java Edition demonstrates how the language’s core strengths translate across different domains.

Consider how Minecraft generates its seemingly infinite worlds. The game engine uses Java’s object-oriented architecture to manage countless blocks, each with its own properties and behaviors. This mirrors how enterprise systems handle millions of business objects or how AI applications process vast datasets. Each block in Minecraft is essentially an object instance managed by Java’s efficient memory system—the same system that helps large-scale enterprise applications maintain performance under heavy loads.

Java’s enduring success is due in large part to the comprehensive ecosystem that has evolved around it after decades of enterprise use. The ecosystem builds on a powerful universal foundation: the Java Class Library (JCL). Think of JCL as a shared toolbox that every Java developer can rely on, whether they’re building fraud detection algorithms in São Paulo or recommendation engines in San Francisco. Just as the coordinated universal time (UTC) synchronizes clocks globally, Java developers everywhere work with these same tested, reliable building blocks.

This standardization has sparked a thriving global community that has built an expansive collection of open source tools on top of Java’s foundation. When developers face a new challenge, chances are the Java ecosystem already has a proven solution ready to use. For instance, when building enterprise applications, developers can leverage Spring’s dependency injection or Hibernate’s ORM capabilities, both of which extend the JCL’s fundamental database connectivity features.

Spring Boot relies heavily on JCL to supercharge Spring, making it faster to build production ready applications. Here’s a spring boot example of how modern Java applications pull on the larger Java ecosystem to handle the common scenario of generating and sending personalized email-based notifications:

@Servicepublic class SmartEmailService extends BaseNotificationService {    private final EmailClient emailClient;    @Autowired    public SmartEmailService(UserRepository users, AIModelClient aiModel, EmailClient emailClient) {        super(users, aiModel);        this.emailClient = Objects.requireNonNull(emailClient, "EmailClient cannot be null");    }    @Override    public String generatePersonalizedMessage(String userId) {        User user = users.findById(userId)                .orElseThrow(() -> new UserNotFoundException("User not found: " + userId));        UserEngagement engagement = getUserEngagement(userId);        var content = aiModel.generateContent(                user.getPreferences(),                engagement.getInteractionHistory(),                engagement.getResponseRates()        );        return content != null ? content : "Personalized message unavailable";    }    @Override    public void send(String userId, String baseMessage) {        User user = users.findById(userId)                .orElseThrow(() -> new UserNotFoundException("User not found: " + userId));        String personalizedMessage = generatePersonalizedMessage(userId);        String finalMessage = combineMessages(baseMessage, personalizedMessage);        emailClient.sendEmail(user.getEmail(), finalMessage);    }    private String combineMessages(String base, String personalized) {        String trimmedBase = base != null ? base.trim() : "";        String trimmedPersonalized = personalized != null ? personalized.trim() : "";        if (trimmedBase.isEmpty()) return trimmedPersonalized;        if (trimmedPersonalized.isEmpty()) return trimmedBase;        return trimmedBase + "\n\n" + trimmedPersonalized;    }}

This code example shows a few core Java principles: interfaces define clear contracts, inheritance enables code reuse, and polymorphism allows for flexible implementations. Spring’s integration demonstrates how Java’s ecosystem offers solutions for common enterprise needs from dependency management to application configuration.

By combining standardized foundations with powerful frameworks, Java allows developers to focus on solving business problems instead of reinventing basic infrastructure. This efficiency is part of the reason why Java remains the backbone of mission-critical systems across diverse industries.

AI ready: Java’s role in AI

While Python may dominate AI research headlines, Java’s robust ecosystem and reliability make it well suited for deploying AI solutions at scale in production environments. For instance, Uber’s Michelangelo machine learning platform extensively uses Java in its production infrastructure to serve real-time predictions, such as Uber Eats delivery times or ride demand forecasts across millions of requests daily, showcasing Java’s ability to handle high-throughput, low-latency workloads seamlessly.

Moreover, through frameworks like Deeplearning4j, LangChain4J, and integrations with tools like TensorFlow, organizations can enhance their existing Java systems with AI capabilities rather than rebuilding from scratch.

Consider a bank’s fraud detection system or an ecommerce platform’s recommendation engine: these are typically Java-based applications, and some organizations are experimenting with adding AI features to them. Rather than rewriting these critical systems in Python, which is a common language in AI, companies can use Java’s AI libraries to add intelligence, which helps avoid costly rebuilds while maintaining the security, reliability, and performance of the systems at hand.

Learning Java: A strategic path to career growth in software development

For many developers—myself included—learning Java isn’t just a hobby, but a strategic career move. As one of the most in-demand languages in the job market, Java can open doors to a wide range of opportunities from developing Android apps to building financial trading systems to crafting large-scale web applications to building the next version of Minecraft (goals, am I right?).

But learning any new language can be daunting—especially one with as much depth and breadth as Java. Fortunately, the resources for learning Java have never been better. Educators like Barry Burd, a professor at Drew University, are using Java’s new features, such as Records and Sealed Classes, to make the learning process smoother and more intuitive. Records eliminate the boilerplate of data classes, helping students focus on concepts rather than syntax, while Sealed Classes provide clear, enforceable hierarchies that make inheritance more understandable.

“I’ve been revising my introductory Java book using Java 23’s Implicitly Declared Classes preview features, and as an author and educator, these features make my work much easier,” Burd said in an interview with The New Stack. “Much of the verbose code in previous editions has gone by the wayside, which helps students concentrate on essential logic.”

The rise of online learning platforms, coding bootcamps, and AI developer tools like GitHub Copilot has also made it easier to pick up practical Java skills. With GitHub Copilot Free, for instance, you can ask questions about a codebase via Copilot Chat and get detailed explanations about key topics—or try writing code yourself and use Copilot’s suggestions to learn how Java works on the ground.

The future of Java: innovation meets stability

More than any specific feature or update, Java stands apart is its unwavering commitment to its core principles. Java has always been about empowering developers to write code that is robust, scalable, and maintainable.

Looking for hands-on practice? Check out beginner-friendly Java OSS projects like Exercism Java Track (coding exercises) and Strongbox (an artifact manager). These projects on GitHub offer approachable codebases and opportunities to learn core Java skills while contributing to real software.

If you’re developing enterprise-level systems or just starting in software development, Java provides a clear and rewarding path for growth (and did we mention it’s one of the most in-demand languages for professional developers?). Ready to add your code to it?

P.S. Not sure how to get the most out of Copilot’s options? Check out our Copilot Chat Cookbook with a collection of sample prompts covering common coding scenarios.

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