Prepare for an interstellar voyage through the exciting universe of Java Long-Term Support (LTS) versions! Join us on a thrilling teleportation adventure as we explore the advancements and stellar features from Java 11 to the cutting-edge Java 21.
Through this cosmic expedition, we will unveil the captivating features introduced in each version, such as enhanced pattern matching, streamlined garbage collection algorithms, futuristic records, and the integration of advanced cryptographic tools.
Buckle up as we traverse the galaxies of dynamic language updates, novel APIs, and improved security mechanisms, all ensuring a seamless journey for developers and their starship-grade applications. By the end of our trek, you will be equipped with a comprehensive understanding of the revolutionary enhancements in Java versions 11 to 21. Live and code long and prosper !!!

Writing tests is not the greatest joy for most developers, especially when tests require lots of boilerplate code and are therefore difficult to understand and maintain. At Chrono24, we took Uncle Bob’s suggestion to write contra-variant tests [1] seriously. We have developed a testing framework that allows us to write tests that are easy to understand, don't cause refactoring problems, and are fun to write. In this talk, we will show how we have structured our tests to achieve this. We'll also explain the principles and tools you can use to do the same in your organization.

Java 21 releases one of the most anticipated features, virtual threads, and previews structured concurrency. It rethinks the way multithreading works in Java. It was born out of the idea that reactive Java is too complicated and blocking threads has to be cheap. Resulting in the new virtual threads that we run thousands of! The aim of virtual threads and structured concurrency is to have high-throughput lightweight threads and new programming models on the Java platform. In this talk, I will demonstrate virtual threads and how to create and manage them using structured concurrency. Furthermore, I'll provide some practical advice to avoid pitfalls when you start using virtual threads in your application.

Using Kotlin makes your code shorter, safer, more fun to write and easier to read! Kotlin is so much more than just syntactic sugar for Java, it is a different and better way of programming.This talk will highlight some key aspects of Kotlin by comparing it to the “old Java way” to get you hooked. Afterwards, I will show you how easily you can start your own journey to improving your life (or at least your code) by using Kotlin. And along the way, I’ll share some stories of my own experience working in a team of Java engineers switching to Kotlin.

Our applications start to grow, our technical skills evolve, technical debts need to be fixed… and at that moment you don't know where to start the refactoring?In this presentation you will learn the principles of refactoring, code smells and refactoring techniques: Extract Function, Extract Variable, Encapsulate Variable, Introduce Parameter Object, Split Phase, Extract Class, Remove Middle Man, Hide Delegate, Move Function, Remove Dead Code , Change Value to Reference, Decompose Conditional, Introduce Assertion, Replace Constructor With Factory Function, Pull up method, Extract Subclass and Collapse Hierarchy techniques based on Martin Fowler's book Refactoring.