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Supersonic subatomic… Java

18.09.2019 |by drazen | 0 Comments | ,

The world is changing. And enterprise application development as well. For years the most important thing was having a stable ground that allowed for a long unstoppable life of the apps. Development experience and quick deployment turnaround cycles were always a second priority. And were often fixed by automagic tools and frameworks. Startup time was another aspect that was not that important. And why it should be for applications that ran for months without a single restart.

But as we said, the world is changing. Flexible payment models offered by serverless put the startup time on a different perspective. And the emergence of quick turnaround and immediate feedback technologies and platforms like Node.JS and Python questioned the negligence that Java used to have for developers’ experience.

The world is changing, so is Java. 2019 saw the proliferation of new breed of Java platforms. And in this session we are going to look at one of them: Born beginning of March, it quickly got traction with its almost revolutionary features.

Come to this session to see some of these features in action:
– Refresh on save for Java applications
– Supersonic start with and without Graal VM
– Subatomic size of the deployment with and without application server
– Awesome development experience for working with databases
– Integration with Kafka for messaging and Prometheus for metrics
– Support for core Java EE technologies and MicroProfile

The talk will be delivered by the big friend of NisJUG – Ivan St. Ivanov (@ivan_stefanov). Ivan is a founder and senior programmer @ VIDA Soft, Open source fan, MicroProfile contributor, Bulgarian JUG lead, jPrime conf organizer, University teacher, PhD student. In addition, Ivan is an official Java Champion.

In the end, we’ll organize a raffle, where you’ll have a chance to win free JetBrains licenses, for IntelliJ IDEA Ultimate or other JetBrains IDE. On top of that, you’ll have a chance to win free tickets for the Heapcon conference in Belgrade (26.-27. Sept).

This meetup has been supported by Deavensoft.deavensoft

Deavensoft is a cloud-native software development company. We are helping our customers to ship their business to the clouds.


Migrating to JUnit 5

07.05.2019 |by drazen | 0 Comments | ,

JUnit 5 release was more than a year ago. More than enough time for JVM ecosystem to adapt and support it. Maven or Gradle, Eclipse or Intellij, Spring or Mockito – your tools of choice now support JUnit 5.

What are the cool new features?
Do I need to rewrite all my JUnit 3 and 4 tests?
Do you need to migrate at all?
How do you migrate?
Is it hard?
Is there something not yet supported?
Will I be able to migrate my own project after this event?

Come and find out!

Note: The talk will be in English. At the end we’ll organize a raffle, where you’ll have a chance to win free JetBrains license (for IntelliJ IDEA Ultimate or other JetBrains IDE) and tickets for jPrime 2019, Java conference in Sofia, 28.-29. May 2019, organized by our friends from BgJUG.

Kostadin Golev (@kotseto)
Bulgarian Java User Group
Team Lead – Simulation Algorithm Development, Ocado Technology – Bulgaria

Kostadin is an experienced Java Developer and team leader with strong interest in unit testing and software design. Always on a quest of continuous improvement, Kostadin believes small efforts over time quickly add up. When not busy with work and family, he likes to write and share his experiences at

This meetup has been supported by Startup Center Niš and the company Thank you! is member of NSM engineering, Swiss software company, with headquarters in Zurich, and gathering internationally experienced teams of software engineers in Belgrade and Niš. In our development centers with more than 240 employees, we develop and manage highly complex software solutions for discerning clients. We are guided by clients’ needs and provide solutions that directly meet their market needs.


jPrime tickets:

  • Djordje Mijatovic
  • Vujica Miljakovic

JetBrains license:

  • Srdjan Bogojev

The SOLID principles of Object Oriented Design

11.04.2019 |by drazen | 0 Comments | ,

In object-oriented computer programming, SOLID is a mnemonic acronym for five design principles intended to make software designs more understandable, flexible and maintainable. The principles are a subset of many principles promoted by American software engineer and instructor Robert C. Martin. SOLID represents principles of class design, yet many Java developers are not aware of them.

For this meetup we’ll have 5 short presentations about SOLID principles, with examples in Java. Our presenters are:

  • Single responsibility principle, Branislav Čolaković [slides] [code]
  • Open–closed principle, Vladimir Ilić [slides]
  • Liskov substitution principle, Dijana Lukić [slides] [code]
  • Interface segregation principle, Petar Becić [slides] [code] and
  • Dependency inversion principle, Dragan Raković [slides].

After that, we’ll have a discussion and a raffle, where you’ll have a chance to win free JetBrains license (for IntelliJ IDEA Ultimate or other JetBrains IDE) and a ticket to jPrime 2019, Java conference in Sofia, 28.-29. May 2019.

This meetup is supported by Startup Center Niš and company Seavus.


Seavus® is a software development and consulting company with a proven track-record in providing successful enterprise-wide business solutions. The company has over 900 IT experts worldwide and offers a variety of products and service options, successfully covering the European and US market from several offices in the world. Their expanding portfolio covers: BSS/OSS, CRM, CEM, Business Intelligence solutions, ALM, embedded programming, business and consumer products, mobile and gaming solutions, managed services, as well as custom development, consultancy and resourcing. Seavus portfolio includes over 3.500 customers, among which leading worldwide telecoms and handset manufacturers, organizations from the banking and finance industry, consumer electronics, technology, education, government, health, etc.

Raffle Winners

  • JetBrains ultimate license: Vladan Petković
  • jPrime 2019 conference pass: Jovan Spasić

Congratulations! 🙂


Let’s talk about Apache Kafka and What’s new in Java

06.12.2018 |by drazen | 0 Comments | ,


Let’s gather once more and talk about Java (and related stuff). Please, confirm your presence using next form:


The presentations for this meetup are:

1. Apache Kafka (by Petar Becic)
Explore main Kafka features and understand why Kafka is one of the most popular Message Brokers nowadays

2. What’s new in new Java versions (by Nemanja Petrović) [slides]
Last year was big for Java, 3 new version, one more coming, new release cycle and more. So let’s see what is new in new Java versions.

This meetup has been organized with the help of a company Miticon ( Thank you for your continuous support of the community!

Miticon is a successful California based Web Development and Digital Marketing Company which serving selected group of high-profile clients. As a forward thinking company that commands excellence in the fields of design and technology, Miticon is recognized by the biggest names of the entertainment industry. Disney, Warner Bros., Sonos, MAPP and Hyperloop are just a few of the clients that have established successful long-term partnership with the company. With the unique way of approach to ambitious projects in digital marketing, technology and website development Miticon creates customized solutions to the top clients in the industry. Miticon team, based in California and Serbia, successfully covers US and European markets.