Is Java Still Relevant in 2021? Is It Still Used?

Marlena Walburg

When a technology has existed already for years, questions like “Is it still relevant?” appear often. There is nothing strange about that but it is not a golden rule that after a long presence, all technologies become obsolete. Java, although very mature, seems to be safe and sound. What may be surprising for some people, Java is still very trendy. When you look at different studies or surveys on the most used, demanded, or loved languages, you will see Java in top positions. What makes this a bit old technology so appealing then? 

What is Java?

Java is an extremely popular programming language released in 1995 as a core component of Sun Microsystems’ Java platform. It is class-based, object-oriented, and has as few implementation dependencies as possible. Moreover, it is a general-purpose programming language that allows application developers to write once, run anywhere, which means compiled Java code can run on all Java-enabled platforms without recompiling. Such applications are typically compiled into bytecode that can be run on any Java Virtual Machine (JVM) regardless of the underlying computer architecture. The language’s syntax is similar to C and C ++. The Java runtime provides dynamic capabilities such as code reflection and modification at runtime that are not typically available in traditional compiled languages. For the curious, the name Java comes from Indonesian coffee, and initially, the language was supposed to be Oak, after an oak tree that stood outside the Java creator’s office.

Why is Java so popular?

Despite being quite a mature technology, Java seems to still be a trendy choice for the development of various types of digital products. According to surveys, Java was one of the most used programming languages among developers worldwide in early 2020. One of the reasons for this phenomenon is Java’s platform independence. As long as the computer has a Java Runtime Environment installed, a Java program can run on it. A variety of types of software that can be developed with it is also a big yes for Java. What is more, programming in Java is considered easy and enjoyable. Having developers who enjoy their job and are not frustrated while writing the code brings benefits to your business, too. The huge support of the continuously growing Java community is another strong point of the technology.

Benefits of Java

No wonder that Java is such an adored language – it has many advantages not only for developers but for businesses as well.

  • Simplicity – compared to other programming languages, Java is quite straightforward to learn, code, compile and debug. It uses automatic memory allocation and garbage collection, and is less complicated than, for example, C++;
  • Object-oriented – Java is based on an object-oriented programming paradigm which means that developers can create modular programs and reuse previously written code; 
  • Memory allocation – In Java, memory is divided into two parts – heap and stack. Whenever a developer declares a variable, Java Virtual Machine gives memory from either stack or heap space. It allows us to keep the information and restore it easily;
  • Multithreaded – in case of programming, a thread is the smallest unit of processing. Multithreading is the process of executing two or more threads of the same process simultaneously. Java allows for that to maximize utilization of CPU time. It brings such advantages as saving time because we can perform many different actions simultaneously, it results in non-blocking code and does not allow for a single thread to affect other threads;
  • Write Once Run Anywhere approach – Java has wide, cross-platform usage possibilities. You can easily create a Java program Windows, then compile it to bytecode and run the application on any other platform that supports a Java Virtual Machine. All major operating systems including Mac OS, Windows, and Linux support JVM.

Disadvantages and alternatives to Java

Let’s see, what cons Java has:

  • Performance – Java is significantly slower than natively compiled languages such as C or C++. Although it has lots of useful features, these can also affect performance when taking more than 20% of CPU time. Bad caching configuration can also cause excessive memory and garbage collection usage. Moreover, it is pretty memory-consuming; 
  • Not so satisfying look and feel on the desktop – to create a graphical user interface (GUI) of any program, programmers use different tools dedicated to specific languages. For Android apps, developers have Android Studio which assures building apps with a great native look and feel. When it comes to desktop UI, Java noticeably lacks such facilities. There are some GUI builders available but unless you are using templates, you will notice interface inconsistencies. The most popular of them are Swing, JavaFX, and SWT. Unfortunately, they are either old or not very suitable for complex UI;
  • Complex and wordy code – the code written in Java is quite wordy and often over-complicated. As a result, it is less readable and approachable. Java is a high-level language that tries to imitate English and so, it tends to make too much noise. It forces developers to type exactly what they mean which makes Java more transparent to beginners but also, less compact.

Java alternatives:

  • Kotlin – this cross-platform, statically-typed general-purpose language is designed to fully interoperate with Java. Kotlin mainly targets the JVM but also compiles to JavaScript or native code. In 2019, Google announced that Kotlin is now its preferred language for Android App development. eventually, many developers switch to Kotlin from Java. To learn more about what is Kotlin used for we invite you to read our related article on this topic;
  • Python – this language highly emphasizes code readability. Created in the late ’80s, Python is an interpreted, general-purpose programming language that supports many good paradigms and has a  comprehensive standard library included. Python Package Index, the official repository for third-party Python software, contains thousands of packages with a wide range of functionalities,  including test frameworks, mobile app development tools, web frameworks and more. 

What is Java mostly used for?

As Java is valued for its extensive usage capabilities, take  a look at some of the implementation examples:

Mobile Apps

Java was for a very long time the official language for Android mobile application development. Before introducing other, new frameworks, most of the Android applications were built using it. For developers who are already familiar with Java, it will be much easier to create such applications, even while working with other technologies. 

Web Apps

Same as with mobile apps, Java is used for developing web-based applications. One of the reasons for that is great support for web development through Java’s technologies – JSP, Servlet, and Struts. With these technologies, you can develop a variety of applications. Java is also used for server-side programming. 


Java is widely used for game development as it has the support of a powerful 3D engine. When it comes to designing 3D games, the engine provides unparalleled capacity. There are some popular frameworks and libraries available for game development like LibGDX and OpenGL.

Big Data Technology

Java remains the first choice in terms of big data management. The Hadoop framework, written in Java is one of such platforms for processing and storing big data apps. Java is widely used in ETL applications such as Apache Camel and Apache Kafka. It is used to extract and transform data, and load in big data environments.

Is Java still worth learning? 10 reasons to learn Java in 2021

1. Highly user-friendly and easy to learn

Programming in Java uses a syntax similar to that in English, just as the developers intended. Any beginner who wants to learn Java can start with Core Java and then move on to Advanced Java. With a working knowledge of C and C ++, the developer’s learning curve will go up because Java syntax is similar to these two languages.

2. Universal and platform-independent

Developers have long relied on Java for web and Android applications. With the high-level tools and packages available, Java applications have expanded to IoT, data science, and machine learning applications. Moreover, Java has the advantage of being portable and compatible across multiple platforms. Once the Java product is ready, it can be deployed on any operating platform. JVM (Java Virtual Machine) is compatible with almost all existing operating systems and hardware. When there is no need to change existing hardware or operating systems, total project costs are automatically reduced.

3. Very demanded language

It may seem shocking with Java’s more than 25 years of presence in the industry, but programmers who know Java well are still in high demand. There are many resources available on the Internet that can be ideal for the learning process, as it is a mature programming language. Java is so widely used that its developer can still find many jobs in any technology industry. Additionally, the popularity of Android applications has brought countless opportunities for an Android developer to write native applications in Java. 

4. Support of the robust community

The Java community has a huge impact on its current state. It is thanks to the people around it that Java is so popular, and developers can count on mutual support in learning, solving problems, finding optimal solutions. Community support has played a major role in developing Java, good practice and reputation. Java is known as the second-largest solution in the Stack Overflow community.

5. Offers rich API

One of the main reasons for the enormous success of the Java programming language is its ability to adapt to user requirements. It achieves this through its rich API that Java provides for almost everything. It also has many methods available. Java can take care of database connections, data input and output, networking, and more. Java also consists of many open source libraries such as Apache Xerxes, Google Guava, Apache Commons, etc.

6. Great documentation

Java documentation, developed and refined over the years, is of really high quality. As an open-source, free programming language, everyone has access to it. This makes learning Java much easier, and also affects its continuous improvement.

7. Powerful development tools

Java is a technology that offers many tools to facilitate developers’ many programming tasks. One such component is the Integrated Development Environment (IDE). The Java IDE is a comprehensive suite of various editors, automation tools and debuggers. The most popular Java IDEs are Eclipse, NetBeans and IntelliJ IDEA. In terms of tools, Java has Jenkins for continuous integration and delivery, JConsole and Visual VM for monitoring the use of Heap, and Maven and ANT for developing Java applications.

8. Cost-effective development

With its stability, maturity and platform independency, Java is a cost-effective solution for any kind of business. When you build a Java product, it can be deployed on any operating platform later on. Java Virtual Machine is compatible with nearly all available platforms and hardware, as we already mentioned. It is an ideal solution when you do not want or need to change your hardware or operating systems. Eventually, the total project will be lower. Moreover, Java development gives a lot of opportunities – you can create mobile apps, web apps and more with this language.

9. Enhanced security

Java is designed to be easy to use and type-safe. Providing garbage collection, automatic memory management, range checking on arrays and more, leads to less burden placed on the backs of developers, and as a result, fewer errors and more robust, safe code. Additionally, Java assures methods, good practices and tools to make developers’ work easier, also in case of security. 

10. Scalability

Java applications are highly scalable due to the wide availability of components. No matter at what point you want to scale your applications horizontally or vertically, Java makes it possible. So when planning an application that grows with more features in the future, Java may be a good choice.

So, is Java still relevant in 2021? Summary

In numerous cases, Java will still be the best, most suitable option. Just think about microservices, enterprise-level web apps, or banking platforms – Java remains a hot pick for building them. Every industry would benefit from Java development and in some of them, like in the finance industry, Java is one of the most demanded to know. Hence, the conclusion is simple – Java is an essential player and it will be for a long time.

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