What is Java?

One major advantage of developing software with Java is its portability. Once you wrote code for a Java program on a notebook computer, it can be easily moved to a mobile device. When the language was invented in 1991 by James Gosling of Sun Microsystems (later acquired by Oracle), the primary goal was to be able to "write once, run anywhere."

It's also important to understand that Java is much different from JavaScript. JavaScript does not need to be compiled, while Java code needs to be. Also, Javascript only runs on web browsers, while Java can be run anywhere.

New and improved software development tools are coming to the market at a remarkable pace, displacing incumbent products once thought to be indispensable. In light of this continual turnover, Java’s longevity is impressive; more than two decades after its creation, Java is still the most popular language for application software development. Developers continue to choose it over languages such as Python, Ruby, PHP, Swift, C++ and others. As a result, Java remains to be an important requirement for competing in the job market.

IBM® offers a simple tutorial to learn Java for building a scalable web application by using Kubernetes and the Java platform.

Before exploring why it remains popular, let us review what Java is in more detail and its importance for enterprise application development.

Java is a technology that uses both a programming language and a software platform. To create an application using Java, you need to download the Java Development Kit (JDK), which is available for Windows, macOS and Linux®. You write the program in the Java programming language, then a compiler turns the program into Java bytecode—the instruction set for the Java Virtual Machine (JVM) that is a part of the Java runtime environment (JRE). Java bytecode runs without modification on any system that supports JVMs, allowing your Java code to be run anywhere.

The Java software platform consists of the JVM, the Java API and a complete development environment. The JVM parses and runs or interprets the Java bytecode. The Java API comprises an extensive set of libraries that include basic objects, networking and security functions, Extensible Markup Language (XML) generation, and web services. Taken together, the Java language and the Java software platform create a powerful, proven technology for enterprise software development.

If you are an enterprise application developer, you know what Java is and it’s likely that your organization already has thousands, even millions, of production line code written in Java. You likely need some level of Java expertise to allow you to troubleshoot, maintain and upgrade your existing codebase.

However, it would be a mistake to view Java only in terms of legacy applications. The Java language forms the heart of the Android operating system, which powers by far the largest share of the world’s smartphones. Java is also among the most popular languages for machine learning and data science applications. Its robustness, ease of use, cross-platform capabilities and security make Java the language of choice for internet solutions in many enterprise shops.

In particular, Java technology is an ideal framework for developing web applications, the foundation for a digital business in any industry. Java application servers are web containers for Java components, XML and web services, which interact with databases and provide dynamic web content. Java application servers form a stable deployment environment for enterprise applications with functions including transaction management, security, clustering, performance, availability, connectivity and scalability.

When it comes to choosing a programming language and environment for your next enterprise application, there are solid technical reasons to consider Java, including interoperability, scalability and adaptability.

The core philosophy behind its creation—interoperability across disparate devices—remains the strongest argument for favoring Java for new enterprise applications. Java’s object-oriented architecture allows you to create modular programs and reusable code, shortening development cycles and extending the longevity of enterprise applications.

Platform scalability is a key attribute of Java. With Java, you can use one single system across a broad range of use cases. Existing desktop applications can be easily adapted to run on smaller devices that have limited resources. You can also migrate applications from mobile to desktop, develop business apps for the Android platform and then integrate them into your current desktop software, which in turn bypasses lengthy and expensive development cycles.

Java also wins points with strategic planners for its ability to adapt to new use cases. For example, Java is widely considered to be an ideal platform for the Internet of Things (IoT). The typical IoT application interconnects a large number of disparate devices, a task that is greatly simplified by the fact that billions of devices run Java. Furthermore, Java’s extensive ecosystem of developers is constantly developing and sharing new libraries with functions specifically aimed at IoT application development.

The technical arguments for Java are compelling, but the business reasons to choose Java are equally strong: a large talent pool, a short learning curve and a wide range of integrated development environments (IDEs).

As more companies use connected devices, machine learning algorithms and cloud solutions, the demand for skilled developers continues to grow. Many analysts foresee a scarcity of senior-level programmers in the near future, making it difficult to staff new software initiatives. Demand for mobile app developers could soon easily exceed the available supply.

The large talent pool of Java developers constitutes a compelling reason to base major software initiatives on Java. When staffing managers post job openings for Java developers, they can expect to receive many qualified resumes and fill those positions relatively quickly. Managers can also draw on contract resources to supplement in-house staff for specific tasks without adding headcount.

In addition to senior-level developers, major software initiatives also require large numbers of junior contributors. While Java remains to be a popular introductory programming language in university computer science curriculums, many graduates lack the proficiency to be productive on day one. Java is easier to learn and master than many other programming languages, leading to a shorter learning curve and faster ramp-up to productivity. Java’s extensive online community of developer forums, tutorials and user groups helps beginners get up to speed fast and provides seasoned programmers with effective, proven problem-solving tools.

In the area of programming tools, Java offers a range of IDEs. Experienced Java developers can quickly ramp up on a new environment, which frees development managers to choose the IDE that best fits the project, budget, development methodology and programmer skill level. Many seasoned Java programmers think of NetBeans, Eclipse and IntelliJ IDEA as the top three IDEs for enterprise application development. But there are cases where a more lightweight IDE such as DrJava, BlueJ, JCreator, or Eclipse Che is the best choice.