Java: The Enterprise Language That Keeps Delivering

Java has been a dominant force in enterprise software for nearly three decades. It runs banking systems, retail platforms, logistics applications, government services, and the back ends of some of the most heavily used web applications in the world. Despite periodic predictions of its decline, Java consistently ranks among the most widely used programming languages on the planet.

This article is written for business decision-makers who want to understand why Java continues to matter, what advantages it offers over alternatives, how the ecosystem has evolved to eliminate vendor lock-in, and what to look for when evaluating Java-based applications and the people who build them.

A Brief History

Java was introduced by Sun Microsystems in 1995 with a promise that was radical for its time: write once, run anywhere. Applications written in Java would compile to an intermediate bytecode that ran on the Java Virtual Machine, which could be implemented on any operating system. In an era when software was tightly bound to specific hardware and operating systems, this was a genuine breakthrough.

Sun Microsystems steered Java through its formative years, building out the standard library, the enterprise edition (Java EE), and the ecosystem of tools and frameworks that made Java practical for large-scale business applications. In 2010, Oracle acquired Sun Microsystems and took ownership of Java. Oracle continued development but also introduced licensing changes that would eventually push much of the industry toward open-source alternatives.

Today, Java is developed through an open process under the OpenJDK project, with contributions from Oracle, Red Hat, Amazon, Microsoft, SAP, and many others. New versions are released on a predictable six-month cadence, with long-term support releases every two years. The language continues to evolve with modern features while maintaining the backward compatibility that enterprises depend on.

Java's original promise of cross-platform compatibility has proven to be one of its most durable advantages. A Java application built on a developer's workstation runs the same way on a Linux production server, a Windows environment, an IBM i system through PASE, or a containerized deployment in the cloud. The Java Virtual Machine abstracts away the differences between operating systems and hardware.

For organizations that operate across multiple platforms, this is not a theoretical benefit. It means the same application code can run on your Linux web servers, your IBM i back end, and your developers' machines without platform-specific rewrites. It means you are not locked into a single operating system vendor. And it means that migrating from one infrastructure platform to another does not require rewriting your Java applications.

This cross-platform story also extends to containerization. Java applications run naturally in Docker containers on Linux, which means they integrate cleanly with modern deployment practices including Kubernetes, CI/CD pipelines, and cloud-native infrastructure. A well-built Java application can move between on-premises servers, cloud environments, and container orchestration platforms with minimal friction.

Compare this to applications built on platform-specific technologies like .NET Framework (Windows-only until the recent .NET Core transition), platform-native compiled languages, or proprietary scripting environments. Each of those ties your application to a specific runtime environment. Java does not.

For years, many organizations ran Java on Oracle's proprietary JDK and accepted Oracle's licensing terms as the cost of using the platform. When Oracle changed its licensing model in 2019 to require paid subscriptions for commercial use of Oracle JDK, it created significant concern across the industry. Organizations that had been running Java for free suddenly faced unexpected licensing costs and the prospect of Oracle audits.

The good news is that Java itself is open source. The OpenJDK project produces the reference implementation of Java, and multiple vendors distribute production-ready, fully supported JDK builds at no licensing cost. These include Eclipse Temurin (from the Adoptium project), Amazon Corretto, Red Hat's OpenJDK builds, Microsoft Build of OpenJDK, and Azul Zulu. Each of these is a complete, standards-compliant Java runtime that can replace Oracle JDK with no application code changes.

This is a direct parallel to the Linux advantage discussed in a previous article. Just as Linux provides freedom from proprietary operating system lock-in, open-source JDKs provide freedom from Oracle's licensing. Your Java applications are not Oracle applications. They are Java applications, and they can run on any compliant JDK.

For decision-makers, the practical implication is clear: if you are still paying Oracle for Java licensing, you almost certainly do not need to be. The transition to an open-source JDK is straightforward and eliminates a recurring cost and audit risk without changing a single line of application code.

One of the most powerful aspects of the Java ecosystem is that the Java Virtual Machine is not limited to the Java language. Other languages compile to the same JVM bytecode and can use the full Java library ecosystem, interoperate with existing Java code, and run on the same infrastructure.

Kotlin, developed by JetBrains and now officially supported by Google for Android development, has become one of the most popular alternatives to Java on the JVM. Kotlin offers more concise syntax, built-in null safety, coroutines for asynchronous programming, and modern language features that reduce boilerplate code. Critically, Kotlin is fully interoperable with Java. Kotlin code can call Java libraries and vice versa. Organizations can adopt Kotlin incrementally, writing new code in Kotlin while continuing to maintain and extend existing Java code.

Groovy is another JVM language with a long history in enterprise development. Groovy's dynamic typing and scripting capabilities make it well-suited for build automation (it is the language behind Gradle, one of the most widely used build tools), testing frameworks like Spock, and rapid prototyping. The Grails framework, built on Groovy, provides a productive full-stack web application framework with conventions that reduce configuration overhead.

Kotlin and Java are also the standard development languages for Android, the operating system that powers the majority of the world's smartphones. Google officially adopted Kotlin as a preferred language for Android development in 2019, and Java has been the foundation of Android development since the platform launched. Organizations that invest in Java or Kotlin expertise for their enterprise systems are building skills that extend directly to mobile application development on the most widely deployed mobile platform in the world.

The ability to choose the right language for each task while sharing the same runtime, libraries, and deployment infrastructure is a significant advantage. It means your investment in Java infrastructure, developer expertise, build pipelines, and deployment processes extends to Kotlin and Groovy code without requiring separate toolchains or runtime environments. And with Android, that investment reaches mobile as well.

Java applications face the same security and deployment challenges discussed in the Linux article. A Java web application exposed to the public internet is subject to the same attacks: SQL injection, cross-site scripting, authentication bypass, insecure deserialization, and dependency vulnerabilities. Spring Security provides robust tools for authentication, authorization, and protection against common attacks, but those tools must be used correctly.

The Log4Shell vulnerability in late 2021, which affected the widely used Log4j logging library, was a stark reminder that even mature Java ecosystems are not immune to critical security issues. Organizations that did not have visibility into their Java dependencies, did not have processes for rapid patching, or did not understand their deployment topology struggled to respond. Organizations with disciplined dependency management, automated builds, and experienced oversight patched and redeployed within hours.

The same principle applies here as it does with Linux infrastructure: the technology is not the risk. The risk is in how it is managed. A well-built Spring Boot application running on a properly hardened Linux server, deployed through an automated CI/CD pipeline, with dependencies tracked and monitored, is a solid production architecture. The same application deployed by someone who does not understand secure coding, does not manage dependencies, and does not understand the deployment platform is a liability.

For organizations in retail, grocery, finance, and other industries subject to PCI compliance, the entire stack matters. The Java application, the application server, the Linux operating system, the network configuration, and the deployment process must all meet the required security standards. This is not a checkbox exercise. It requires people who understand every layer.

Java runs natively on IBM i through the PASE environment, which provides a full AIX-compatible runtime. This means organizations with IBM i systems can run Java applications, Spring Boot services, and JVM-based tools directly on the same platform that runs their RPG business logic and DB2 for i database.

This opens significant integration possibilities. A Java service can query the same DB2 for i database that RPG programs write to, using JDBC. It can expose that data as a REST API for web applications, mobile apps, or external systems. It can run scheduled jobs, process files, and interact with data queues. All of this happens on the IBM i system itself, without requiring a separate server.

For organizations planning a gradual modernization of their IBM i environment, Java on IBM i provides a practical bridge. New functionality can be written in Java or Kotlin while existing RPG business logic continues to run. Data is shared through the integrated database. The organization modernizes incrementally rather than attempting a risky all-at-once replacement.

Java is not trendy. It is not the newest language, and it does not generate the excitement that newer technologies attract. What it offers instead is something more valuable to a business: a proven, portable, well-supported platform with a massive ecosystem, genuine cross-platform compatibility, freedom from vendor lock-in through open-source JDKs, and the ability to run on everything from IBM i to Linux to containers in the cloud.

The decisions that matter are not about the language itself. They are about how your Java applications are built, how they connect to your data, how they are deployed, how they are secured, and whether the people managing them understand the full stack from the JVM to the operating system to the network.

With over 35 years of enterprise software development experience spanning Java, IBM i, Linux, and cross-platform integration, I help organizations make these decisions with practical, grounded guidance. If you have questions about your Java environment, your deployment practices, or how to connect Java-based services with your existing business systems, I would be glad to have that conversation.