• Branko Mihaljević
• Aleksander Radovan

Java in Croatia and HUJAK

Javantura v6 Conference Opening and HUJAK's Community Keynote

• Keynote
• Introductory
• English

Slides

www.slideshare.net

• Ivica Puljak

Future of the Humankind and the Universe

What is the future of Earth and Sun in the close and far future? What is the future of this part of the Universe and how the whole Universe will end? What is the close future of humankind? What is the best way to deal with greatest challenges like climate changes, artificial intelligence, globalisation and generally very fast advancement of technology. What is the future we want? In this session we will discuss answers to these questions, as the basis for further discussion and as food for thoughts.

• Keynote
• Introductory
• Croatian

Slides

www.slideshare.net

• Many Speakers

Sponsors and Friends

Lightning Talks from JavaCro, KING ICT, ecx.io, AG04, RIT Croatia, and others

• Keynote
• Introductory
• English

• Dalibor Topic

Java SE, Today and Tomorrow

What’s new in Java today, and what’s coming to Java tomorrow? This session will review some of the recent enhancements made over the last year to the language and the platform, as well as offer a glimpse into some of the features in development that will continue to improve both developer productivity and program performance while retaining Java’s core values of readability, generality, and compatibility.

• Keynote
• Introductory
• English

Slides

www.slideshare.net

• Dalibor Topic

JDK 11 & JDK 12

In this talk, you'll learn about the new features in JDK 11, the first long-term support (LTS) release in a new, faster Java SE release cadence.
We'll discuss the how these features benefit your code, and how existing code can be brought forward to benefit from JDK 11. Last but not least, we'll discuss how to keep up with innovations coming up in JDK 12, and future releases.

• Core Java, Frameworks, and Servers
• Intermediate
• English

Slides

www.slideshare.net

• Rafael del Nero

Master the Concepts Behind the Java 10 Challenges and Eliminate Stressful Bugs

Bugs are a daily cause of stress in our work as Java developers. Those pesky things can hide behind core concepts in Java 9 and 10—there is no way out of this. If we don’t keep up to date with new Java versions, bugs will take over our projects. But can we have fun hunting them? You bet! How about solving a series of Java puzzles as a way to master concepts and save a lot of time finding those tricky bugs? In this session, attendees can help the bug hunters solve fun Java challenges, gain a clear understanding of what causes the most-stressful bugs—and have fun eliminating them from projects.

• Core Java, Frameworks, and Servers
• Intermediate
• English

Slides

www.slideshare.net

• Matija Dujmović

Spring HATEOAS hypermedia-driven web services, and clients that understand them

HATEOAS is without a doubt, the least understood pillar of REST. It seems difficult to implement and shows no immediate reward for it, so many developers don't even bother. The truth is, it just has some bad PR and a horrible acronym that sounds like a breakfast cereal. Join me to take a look at the theory and practice behind using hypermedia by examining both web services and web clients. Along the way we will look at some exciting upcoming Spring HATEOAS features, like the Affordances API, and talk about what the future holds for hypermedia in your web services.

• Core Java, Frameworks, and Servers
• Introductory
• English

Slides

www.slideshare.net

• Mario Kušek

Building IoT Middleware with Microservices

In H2020 EU project symbIoTe (symbiosis of smart objects across IoT environments) we have been building IoT middleware based on microservices programmed in Java with Spring Boot and Spring Cloud components. Here I will present our experiences in developing such services in distributed team across EU and employed by 15 organizations. I will present organizational and technical advantages and drawbacks as well as our choices in building such system.

• Core Java, Frameworks, and Servers
• Intermediate
• English

Slides

www.slideshare.net

• Aleksander Radovan
• Vjori Hoxha
• Ivor Baric

Predicting future using Java and neural networks

One of the most active areas of research and practice is the use of neural networks for process automation and prediction of events and trends based on an existing dataset. Encog framework written in Java allows the use of neural networks in a simple way to adapt and prepare for that purpose. Two examples of the implementation of such networks for forecasting tsunamis and predicting the level of air pollution in the city of Zagreb will be presented in this talk.

• Core Java, Frameworks, and Servers
• Intermediate
• English

• Adnan Isajbegovic

Developing Enterprise Services with Apache Camel

Apache Camel is an open-source integration framework written in Java and based on Enterprise Integration Patterns.
One of primary goals of this framework is to tackle complexity in large enterprise systems.
With its easy to get API, over 200 components at disposal, it became wildly used from heavy monoliths to complex network of microservices.
This lecture is an introduction to Apache Camel, why and when to use it (with some real life stories) and I will also demonstrate how to setup it with Spring Boot
and show several examples of its mostly used functionalities.

• Core Java, Frameworks, and Servers
• Introductory
• English

• Ioannis Kolaxis

How can you improve the quality of your application?

Do your customers keep complaining about bugs in your software application? Does it take you too much time to implement new features? If yes, then you probably have issues with the quality of your application. Join me to find out what practical steps you can follow to improve the quality of your application!

• Methodologies and Tools
• Intermediate
• English

Slides

www.slideshare.net

• Matea Pejčinović

RAML based REST API documentation

When developing a REST web service, it becomes crucial having a documentation that is accurate, up-to-date and well-structured. There are many tools nowadays that can be used in projects and that will help writing a documentation that will meet the above-mentioned needs. But some of them prove to be just a little more handy in web service development. Spring REST Docs are already known as a tool that has a different approach. But not even its benefits meet all needs a developer has. This especially refers to the cases when there is a project consisted of several microservices. This presentation will show how RAML can be used in order to produce documentation that takes into account all benefits of Spring REST Docs while also introducing a lot of possibilities out of the box. A simple example will be used in order to demonstrate this approach and some features.

• Methodologies and Tools
• Introductory
• Croatian

Slides

www.slideshare.net

• Tomislav Klišanić
• Ivan Krnić

"1-click" OpenShift provisioning

Organizations draw agility from their organization (pun intended!), but also from technical practices that enable quick and reliable delivery of business value to end users. One of those practices is capability to quickly provision new runtime environments with specific configuration in order to test applications in real-life conditions. Organizations achieve best results when they are able to store all necessary data in configuration management system and therefore adhere to Infrastructure as Code principle. In this talk we will show how we implemented "1-click" provisioning of OpenShift system using Ansible and AWX (and had fun doing it).

• Methodologies and Tools
• Intermediate
• English

• Hrvoje Ruhek

Automation of web apps testing

Quality control during apps development demands continuous testing. Selenium, Cucumber, Jenikns and Docker can help us in that process. Hrvoje will share his experience about that subject.

• Methodologies and Tools
• Introductory
• Croatian

Slides

www.slideshare.net

• Jurica Krizanic
• Marija Malkoč Kušt

When remote work really works - the secrets behind successful distributed teams

With several years of remote work experience in an agile environment, working from beautiful Zagreb for clients abroad and trying out different distributed team setups, we will share the motivation and philosophy behind it. We will also cover best practices, challenges and general tips & tricks in different segments such as work organisation, technical requirements, social requirements, methodology etc.
This talk is recommended for all developers who want to start working remotely or improve the way they already do it, employers who consider establishing distributed teams inside of their companies and clients searching for partners who have distributed teams.

• Methodologies and Tools
• Introductory
• English

Slides

www.slideshare.net

• Marko Elezovic

Monorepo s(i)tories

At first glance mono everything sounds pretty bad.
God objects, overpowered classes violate limited responsibility principles, and monolithic megaprojects sound less sexy then microservices.

So why would version control be any different - monorepositories must inherently be bad, as they're overpowered and cumbersome!
But, with some grey hairs (from stress, mostly), one tends to view things holistically. There is Yin and Yang in every approach and one needs to critically weigh options to apply to a workflow.

The talk will describe the different work patterns one employs on mono vs scattered repositories. We'll explore how best practices in hashing and caching can promote agility even with large repositories.
Expect a mini pitch for the open source `monohash` library, as well as concrete CI/CD integration examples from Oradian, should the demo gods allow.

• Methodologies and Tools
• Intermediate
• English

• Josip Pojatina

Java Mission Control now in OpenJDK - best practice

If there is one tool that have almost all what is needed for monitoring, troubleshooting and tuning Java apps, that will be JMC. There are several reasons why JMC will be a hot topic in Java events from now on:
- More than 95% of all issues related to JVM, application servers, deployed apps and even OS can be resolved by leveraging JFR and JMC
- less than 3% overhead makes JFR ideal for production environments
- Java Flight Recorder is Open Sourced now and it's bundled with OpenJDK 11
- Java Mission Control went Open Source too, thus both components can be used in production
Although latest version 7.1 is in Early Access state, even now you can play with and figure out what you can expect in the final release.
From Automated Analysis results, through the spectacular views of most important events, flexible configuration, filtering only events of interest, this tool will become (and already is) pearl in Java developing, monitoring, troubleshooting and tuning.
Equipped with GPL license, it's not difficult to imagine that the whole ecosystem will be created around with dozens of plug-ins (in Oracle JDK version of JMC there are just a few plugins available like JConsole, DTrace Recorder, WebLogic Tab Pack and few more).
In presentation several topics will be described:
- how to install Open Sourced version of JMC
- best practice of how to make JFR recordings
- how to analyze results with such formidable powerful tool

• Methodologies and Tools
• Intermediate
• English

Slides

www.slideshare.net

• Matej Vidaković

Kotlin - Java Interop

While Kotlin is designed to work well with Java by default, we'll still need to some work to get clean and idiomatic code in both languages.
In this talk we'll cover both how to make your Java code more Kotlin friendly and how to make your Kotlin code nicer to use from Java.

• Trends, Future, and Community
• Intermediate
• English

Slides

www.slideshare.net

• Jamie Coleman
• Stewart X Addison 🇪🇺

Are you ready for cloud-native Java?

Cloud Native. It's a great term, one that promises significant benefits for Java developers and Java applications. However there are traps for the unwary traveller undertaking this journey. It's best to be prepared and forewarned. In this talk hear more about what Cloud Native Java looks like, and how it can differ from what you might be expecting.
From application to JVM to hosting environment, there are challenges to face and obstacles to overcome before you've reached your goal. This talk will educate and remind you of the important points to be aware of, and will offer an opinionated view of the open technologies you should be including in your travel bag.
Whether a new starter or an old hand, this session will leave you thinking differently about Cloud Native Java!

• Trends, Future, and Community
• Introductory
• English

• Marko Lukša

Istio Service Mesh - The magic between your microservices

Individual microservices are relatively easy to develop, but managing a distributed system composed of microservices is never a simple task. Kubernetes helps, but it falls short of providing everything such a system needs. This is where the Istio Service Mesh comes in.
Running microservices in production, you'll soon realize you want things like traffic splitting, automatic connection retries, timeouts and failovers, secure communication and authentication between your services, distributed metrics, tracing and logging. By introducing Istio into your architecture, you get all of that and more. And you get most of it without changing your code at all.
In this talk, you'll see a demonstration of Istio in action and learn about the tricks that make its magic possible.

• Trends, Future, and Community
• Intermediate
• English

Slides

www.slideshare.net

• Darko Jureković

Oracle Academy in CEE in a glance

Oracle Academy is global Corporate Citizenship program freely available to academic institutions worldwide, from primary and secondary schools to universities. Available program resources range from access to Oracle software products, professional development opportunities for teachers and the provision of educational curriculum levelled to the European Qualification Framework (EQF) which can be used in the classroom to develop computer science learning for students.
Detailed information about the program is available on the following page: https://academy.oracle.com.
The goal of Oracle Academy program is to raise interest and encourage students and pupils at an early age to pursue further education in the field of computer science learning, Java programming, and database design and development.
In this presentation, Oracle Academy activities in Central and Eastern Europe countries (for example: Bosnia and Herzegovina, Croatia, Czech Republic, Hungary, Poland, Slovenia) since last Javantura will also be presented.

• Trends, Future, and Community
• Introductory
• English

• Pavao Varela Petrac

Just say it v2

We are used to give commands to our computers with keyboard - by natural language recognition improvement, services around this technology stack become better and better each day. Using Google Home mini device, IFTTT service and java web socket netty server hosted on red hat Openshift platform, control your loving private computer terminal or any application from distance with your bare voice.

• Trends, Future, and Community
• Introductory
• English

Slides

www.slideshare.net

• Branko Mihaljević
• Matija Šipek
• Paula Pufek

On the Aspects of Polyglot Programming and Memory Management in a VM – GraalVM and Contemporary GCs

This is a story about our exploration of aspects of Polyglot Programming and Memory Management in a (J)VM. The first part is focused on our research of performance of GraalVM, an open-source, high-performance polyglot virtual machine written in Java, as well as an accompanying Graal compiler, supporting JIT and AOT compilation, with outstanding inlining and escape analysis algorithms. In the second part we are dealing with aspects of automatic memory management and garbage collection analysis in an existing JVM, thus comparing the most commonly used (older) garbage collectors such as Serial, Parallel (Old), CMS, and G1, with contemporary and default Parallel Full G1, and new experimental ZGC and Shenandoah, across several JDKs using a common benchmark suite.

• Trends, Future, and Community
• Introductory
• English

Slides

www.slideshare.net

• Miroslav Čerkez

How to help customers report bugs accurately

Bugs happen! It is a developers life fact. Let'e explore one way we the developers can help customers to make batter bug reports.
During lifecycle of systems and applications that support complex and long running business processes it is often the challenge to get accurate bug report. In this talk we will present one custom developed solution that we used on several our projects as well as our experiences in using this approach.

• Innovative and Creative Projects, Experiences and Solutions
• Intermediate
• English

Slides

www.slideshare.net

• Ladislav Mačkala

Case Study: Marketplace App with Java and Hyperledger Fabric

We develop an application prototype with Java and Hyperledger Fabric to facilitate people in the company to sell domestic goods to each other using marketplace application. Java and SmartGWT were used to develop UI, part of data were stored in the relational DBMS, while orders and balances were stored on the blockchain, specifically Hyperledger Fabric.

• Innovative and Creative Projects, Experiences and Solutions
• Introductory
• English

Slides

www.slideshare.net

• Paolo Carta

End to End Continuous Delivery of Microservices for Kubernetes

In the last few years we witnessed big changes in how we actually build, deploy and run applications with the rise of Microservices Architectures, Containers, Kubernetes, and DevOps practices. Those amazing improvements need a cultural shift
based on continuous improvement and learning in order to deliver business value and delight our customers.
But how could a team achieve this ambitious goal?
This talk will introduce the attendees to a revolutionary open source project, called Jenkins X, which attempts to achieve this goal. It is basically a reimagined CI/CD Ecosystem for Kubernetes built around Jenkins, either with a classical master or leveraging knative serverless functions.
After this talk, attendees will be able to develop effectively in a cloud native way in any language on any kubernetes cluster!
Let's forget Scrum and be truly Agile! Finally!

• Innovative and Creative Projects, Experiences and Solutions
• Intermediate
• English

Slides

www.slideshare.net

• Ana Baotić
• Martin Grmek

A lean and flexible approach to rapid mobile development

The fast pace in the fintech industry places great demands on companies to deliver highly modular and functional products. Developers need to support their clients with everchanging UI and business logic requests. How do you utilize your resources to achieve maximum efficiency and reliability, without sacrificing your team's time and sanity?

In this presentation, you will learn how adaptive elements can help you eliminate business logic from mobile, allowing focus on beautiful client-side application while securing Client's business needs. You will walk away with greater insight on how to improve your development process and keep your team happy and productive.

• Innovative and Creative Projects, Experiences and Solutions
• Intermediate
• Croatian

Slides

www.slideshare.net

• Miro Svrtan

Learn by teaching

Have you ever felt there are no new challenges and your career is at the peak?
Do you feel like you received more from the community than you gave back?
While you can always find challenges by switching languages or companies, doing open source or speaking on conferences, I decided to go down a different road: to become a teacher and a mentor. If you are interested in learning more on how and what, join me for this talk.
I strictly enforce 'There are no stupid questions, only stupid answers' guideline, but the types of simple and sometimes silly questions you get from wondering young minds is just amazing!
This talk will cover not only what I learned from teaching/mentoring but give you some guidelines how to start, some tips & tricks and show you how easy it can be to set it all up!

• Innovative and Creative Projects, Experiences and Solutions
• Intermediate
• English

Slides

slides.com