OpenJDK Java

Recently, the task where I used OpenJDK Java  was deploying a Java-based web application on a Linux server using Apache Tomcat . OpenJDK Java served as the runtime environment, and I used it for application testing, configuration, and troubleshooting to ensure stable performance in production.

Besides running and supporting Java-based web applications, I also used OpenJDK Java for learning and testing new Java features, troubleshooting application issues, and working with containerized environments such as Docker  and Kubernetes .

The feature that I have found most valuable is stability and reliability because in my day-to-day work, it helps ensure that Java applications run consistently in development, testing, and production environments with minimal issues. This reduces troubleshooting time and gives me confidence when deploying applications on Linux servers and containerized platforms.

The feature worth mentioning is OpenJDK Java's strong ecosystem and community support because it is widely adopted. There is extensive documentation, a large collection of libraries and frameworks, and plenty of community resources available, which makes development, troubleshooting, and learning much easier.

OpenJDK Java has positively impacted my organization by providing a stable, reliable, and cost-effective platform for running Java applications. Its open-source nature eliminates licensing costs, while its strong performance and compatibility help ensure smooth application deployment and maintenance.

While I do not have exact figures, one noticeable benefit has been avoiding commercial Java licensing costs by using OpenJDK Java. This allows us to run and maintain Java-based applications without additional runtime licensing expenses while still receiving the performance and stability needed for production workloads. Additionally, its reliability helped reduce downtime and troubleshooting effort, improving overall operational efficiency.

The documentation is generally good, but it could be improved with more beginner-friendly guides for upgrades, troubleshooting, and performance tuning. More practical examples for cloud and containerized deployments would also be helpful.

OpenJDK Java updates and patch management are handled through my standard system maintenance process. The infrastructure team regularly applies security patches and version updates during scheduled maintenance windows, with testing performed before deployment to production to ensure application compatibility and stability.

The learning curve is generally moderate. New developers can learn the basics quickly, thanks to Java's clear syntax and extensive documentation, while more advanced topics such as enterprise frameworks, performance tuning, and large-scale application development take additional experience to master.

OpenJDK Java supports compliance efforts by providing a secure and well-maintained runtime environment with regular security updates and patches. While compliance depends mainly on application design and organizational processes, OpenJDK Java helps by offering a stable platform that aligns with enterprise security and governance requirements.

Personally, I expect OpenJDK Java to continue evolving with improvements in performance, security, and cloud-native development. I am particularly keeping an eye on enhancements for containers and Kubernetes environments, better support for modern application architectures, and continued innovation through regular Java releases while maintaining backward compatibility.

OpenJDK Java remains important for my future plans because many enterprise applications and backend services rely on Java. Given its stability, strong ecosystem, and open-source nature, I expect it to continue being used for new applications, modernized services, and cloud-native deployments in the future.

It is generally easy to find developers with OpenJDK Java skills because Java is one of the most widely used programming languages. There is a large talent pool, extensive learning resources, and many developers already have experience with Java-based applications and frameworks.

I would recommend OpenJDK Java to organizations looking for a reliable, mature, and cost-effective Java platform. It offers strong performance, broad ecosystem support, and no licensing costs. My advice would be to choose an appropriate LTS version, establish a regular patching process, and thoroughly test applications before major version upgrades to ensure compatibility. I have provided this review with an overall rating of nine out of ten.

My main use case for OpenJDK Java  is for various development purposes including desktop, web, integration patterns, interoperability, and everything that is usually included in standard enterprise projects and small demo examples that I use in teaching while instructing students at my courses.

The best features OpenJDK Java  offers depend on the version. Usually, the last few versions included virtual threads and all the optimizations that benefit applications including Spring  applications, etc. Nowadays you don't need to rely on platform threads. You can use virtual threads without a problem and create them in vast numbers, not just hundreds, because asynchronous applications are very important for creating an environment in which you can be responsive, and especially in this AI age where you can combine everything together and try to provide your users with the best features and best capabilities of your system. Of course, the latest version includes the Vector API. I'm looking forward to actually using the best features related to that and all those small perks that are added to every single version, such as lambda expression optimizations, HTTP client, JavaFX that I use, and everything that helps you to be productive and to follow the best practices such as SOLID principles, design patterns, and clean code.

OpenJDK Java has positively impacted my organization because the word open actually opens everything more to the community. Usually people don't want to be vendor-locked. That's why they need this opportunity to choose their own platform to create an environment where they feel the most comfortable and of course, the most productive. Every next version of OpenJDK, for example, the last few years we experienced optimization in garbage collectors, etc. Someone can also include their own garbage collector or choose from the list of available and supported garbage collectors. They can have this support that will give them full control over their environments. Everything that is added to the stack every six months also makes the whole community vibrant. We eagerly wait for those short-term releases every six months, but at the end of the day, the latest versions are those that have the most impact to the community.

I think that we need to follow the latest trends and include even more optimization in the language to match the best performing languages so we can get more with less code because Java often requires some kind of boilerplate to achieve many things, but other languages don't require that. This is perhaps the only thing that will naturally evolve in the future. Also since Java was released in 1995, nowadays we celebrate 30 to 31 years of Java existence on the market. There are certainly things that can be optimized. This release cycle every six months is a good one, so I think newer features will be added and of course, older features will be removed. For example, I really don't prefer to use primitive types such as int, long, short, and boolean. I would rather use records or reference types. This could be something that might be more promoted to actually use other reference types rather than using primitive types. I understand how deep this is within the language, so it cannot be extracted or cut off from the platform. However, it's our responsibility to promote the best practices and to use, for example, optional types instead of null references to avoid null pointer exceptions. This is something I really appreciate in Java because avoiding common pitfalls and mistakes helps developers to be more productive.

I have been using OpenJDK Java since I started programming in 2003 when I was a student.

I would like to see some alternative tools that will help developers to start development with AI assistance because JetBrains IntelliJ is something that is really powerful, but when you are no longer a student, you need to pay for the tooling. Before, let's say 20 years ago, we had Eclipse or JDeveloper environments, but they are not keeping pace with the competitors. That's why this open keyword should also popularize the whole Java enterprise and community, etc. It will help to have a tool that will be competitive to the other elements because, for example, we had the Scene Builder for JavaFX that was maintained by Oracle, but they abandoned it. So this parallel thread, let's say Gluon JavaFX is now actually producing good results. That's why this branding is very important. If you actually stand behind a tool that will be created for this new era of development with the help of AI and live coding, it could help the platform to be more popular and of course, involve more than 10 million developers. Although Java is already over 30 years old, it will still be a main competitor on the market. For all enterprise development solutions, Java as an open-source technology could still be the number one choice and stay for a long time as number one.

An example of how I use OpenJDK Java in my teaching and enterprise projects is that since everything I teach is related to Java, I create an object, for example, in the IntelliJ JetBrains environment. Then when a new Java version is released, perhaps version 25 or 26 every six months, I download it through this tool, JetBrains IntelliJ, and configure my project, mostly Spring  projects or vanilla Java projects without any specific frameworks to establish the basic functionality, and then I start developing all the features that are required for this purpose.

At the end of the day, Java is a platform and many open-source libraries and projects are added to the technology stack and then we are implementing enterprise applications, web applications, or even console applications just to show that this is something that can cover everything. With AI, it's much easier because the best models are using the latest Java versions without any problems, so you can immediately be very productive and at the end of the day, you can deliver your application much faster than you could five or six years ago.

I want to show many examples of performance, measurements, reports, and automation such as unit testing, CI/CD, and especially integration with AI regarding how I use OpenJDK Java in my teaching and development.

The efficiency of virtual threads is the first thing that comes to mind when I talk about how virtual threads or any of these features have changed the way I and my students develop applications. Instead of creating platform threads that are very heavy for the system because the memory footprint is 1 MB to 2 MB per thread, with virtual threads, you actually have a footprint of 1 KB, which means that you can create many threads and they can be synchronized, especially if you use asynchronous operations or prefer to have non-blocking changes to every resource that you are contacting with. This is something that can be done much more easily and you can create a pool of threads that you use efficiently, so you can be much more productive when you use those things. Of course, your system can utilize the hardware resources much more efficiently and that's why this is the future of asynchronous parallel development. For example, when you synchronize virtual threads with your main thread in JavaFX UI, you can actually create something that will run in the background without taking too much processor time and actually increase the responsiveness of every application.

I want to highlight especially the newest features that are included in the latest releases, such as the Vector API, because I tested the Vector API a few years ago when it was in the incubation period. It was still promising to actually use some features of CPUs to even better optimize the processing of large data. Especially nowadays we use many datasets when we prepare the datasets to train our LLM models. This is something I would like to highlight and I'm looking forward to getting the final version so I can play with it in my own use cases.

My advice for others looking into using OpenJDK Java is that they need to compare their own solutions to OpenJDK Java and then decide for themselves because it's very important to have a choice, not to be vendor-locked. You should have a choice and compare how good this is accepted, how easy you can actually get all the information, and how good it is accepted across the AI landscape. If the AI generates many examples that can be easily integrated or run on OpenJDK Java, that's the way to go. I give this review a rating of 9 out of 10.