<p>javaBin Tromsø - en brukergruppe for personer interessert i Java og omkringliggende teknologier. Se https://www.java.no/ for mer informasjon om javaBin.</p>


Welcome to the second javaBin meetup in the Foojay Virtual OpenJDK 17+ JUG Tour! This time our guest is Deepu Sasidharan, co-lead of JHipster and creator of KDash. This meetup will look more into Java 17's pattern matching and sealed classes.

All javaBin Online sessions are streamed over YouTube, so you can enjoy them from the comfort of your home office. Before we start, we'll mail the YouTube link to all attendees, and we'll also post in the comments for this Meetup. In addition, we'll set up https://www.java.no/online to redirect directly to Youtube.

AGENDA
- 18:00: Welcome from javaBin
- 18:05: "Pattern Matching & Sealed Classes: Best Features of OpenJDK 17?" by Deepu Sasidharan
- 18.45: Q&A

TALK ABSTRACT:
Let's have a quick rundown of the two most exciting features landing in OpenJDK 17!

Pattern matching in Java is almost complete now. OpenJDK 16 added support for pattern matching in the instanceof operator and now this can be used in switch cases to perform idiomatic pattern matching, as in many other modern languages.

Let's see all the possibilities with it first and then we will look at the new Sealed classes and interfaces that let you restrict inheritance and learn how they can be useful in pattern matching.

SPEAKER BIO:
Deepu K Sasidharan is a Software Engineer by passion & profession. He is the co-lead of JHipster and the creator of KDash. He is a polyglot programmer working with Java, JavaScript, Go, Rust, and so on. He is also a cloud technology advocate and an open-source software aficionado. He is a technology advocate by passion. He has authored books on JHipster and writes frequently about Java, JavaScript, Go, Rust, DevOps, Linux, and so on, on his blog. He works as a Developer Advocate for Adyen.

Sverre Moe

javaBin Online: Pattern Matching & Sealed Classes: Best Features of OpenJDK 17?

Velkommen til javaBin's neste online møte! Vi har fått med oss Terje Heen fra NAV IT, en velkjent foredragsholder i communitiet og kanskje en av Norges fremste når det gjelder å forklare smidig utvikling og gode prinsipper og teknikker innen utvikling. Terje skal i dette foredraget snakke om kontinuerlig refaktorering, og du kan se frem til en meetup med mye spennende temaer på agendaen. Denne meetupen vil bli holdt på norsk.

Meetupen streames live over YouTube. Gå til https://www.java.no/online for å komme direkte til streamen på meetupdagen. Lenkene til streamen postes også her i kommentarfeltet før meetupen starter og sendes også til alle påmeldte i en melding før meetupen starter.

AGENDA
- 18:00: Intro og velkommen fra javaBin
- 18:05: Kontinuerlig Refactoring av Terje Heen
- 19.00: Q&A

ABSTRACT
I denne presentasjonen vil jeg snakke litt om erfaringene jeg har gjort meg rundt kontinuerlig refaktorering av en applikasjon over tid. Jeg vil snakke om teknikker jeg har benyttet, og funn jeg har gjort underveis.

- Cognitive load
- Code smells
- Fravær av forretningsdomene
- Lesbarhet
- Commons, utils
- Dependencies
- Komplisert setup i test
- Ingen design (alt er public)
- Ingen separation of concerns
- Duplikate logginnslag
- Testbarhet
- Forenkle, forenkle, forenkle
- Abstraksjoner
- High cohesion & low coupling
- One reason to change
- Package by layer/feature
- Arkitektur
- Bevist bruk av interfaces

BIO
Terje er utvikler i NAV og brenner for kontinuerlig produktutvikling og enklere løsninger.

javaBin Online: Kontinuerlig Refactoring - Terje Heen

Welcome to our next javaBin Online session with our special guest Andrew Harmel-Law. Andrew will present his talk "Domain-Driven Design: The Bare Essentials (plus Microservices!)"!

All javaBin Online sessions are streamed over YouTube, so you can enjoy them from the comfort of your home office. Just before we start we'll post the YouTube link in the comments for this Meetup. We'll also set up https://www.java.no/online to redirect to the talk.

AGENDA
- 18:00: Welcome from javaBin
- 18:05: "Domain-Driven Design: The Bare Essentials (plus Microservices!)"
- 19.00: Q&A

ABSTRACT
I strongly believe that Domain-Driven Design is one of the best thing to happen to software development in decades. It has within it the key to our hardest problems: how to slice up our software, how to write maintainable software, how to name things ... and most importantly of all, how to meet the needs of our users.

But there's a problem. Despite all this, I see DDD going wrong everywhere. Having used DDD for over ten years I think I know why, and that's what I want to share with you. The three core elements which I call the 'Heart of DDD' and which if you stay true to them will guarantee you succeed.

This talk will have three sections - the first will explain the 'heart' as Eric Evans described it. The second will go back to each and discuss them, and how they interact. The third will look at how they can drive a solid and intuitive Microservices architecture that's a pleasure to work with.

SPEAKER BIO:
Andrew Harmel-Law, Technical Principal, ThoughtWorks.
A highly enthusiastic, self-starting and responsible Tech Principal; Andrew specialises in Java / JVM technologies, agile delivery, build tools and automation, and domain driven design. Experienced across the software development lifecycle and in many sectors including government, banking, and eCommerce, what motivates him is the production of large-scale software solutions, fulfilling complex client requirements. He understands that people, tooling, architecture and process all have key roles to play in achieving this. Andrew has a passion for open source software and its communities. He has been interested in and involved with OSS to a greater or lesser extent since his career began; as a user, contributor, expert group member, or paid advocate. Finally, Andrew enjoys sharing his experience as much as possible. This sharing is not only seen in his formal consulting engagements, but also informally through mentoring, blog posts, conferences (speaking and organising), and open sourcing his code.

Domain-Driven Design: The Bare Essentials + Microservices - by Andrew Harmel-Law

javaBin ønsker alle velkommen til en julespesial! 2020 har ikke vært lett og store deler av året har mange av oss jobbet fra hjemmekontor. Som en takk til alle som har stått på gjennom hele året, avslutter vi året med en meetup med en veldig spesiell gjest. Nemlig Øystein Myhre Andersen, en av utviklerne av det første objekt orienterte språket Simula. Meetupen blir en lengere versjon av Øystein sin lyntale fra JavaZone 2019.

Meetupen streames live kl. 18.00, førstkommende tirsdag den 8. desember. Meetupen blir holdt på norsk og streamen kan følges live fra: https://java.no/online

PS: This meetup will be held in Norwegian.

Abstract:
The 50th anniversary of Simula, the first object-oriented programming language, was held at the Department of Informatics, University of Oslo on 27th September, 2017. James Gosling, the inventor of Java, gave overwhelming credit to the legacy of Simula in his lecture. He mentioned that a number of programming languages nowadays
compile to JVM. During his lecture, I began to wonder - why has no team made a simula implementation in java, written in java that compiles to java / java virtual machine(JVM). Inspired by the lectures on the Simula Jubilee, I began to ask myself if I should try to make a Simula implementation using today's tools. It should certainly be a Recursive
Descent parser followed by traditionally checker and a code generator.

Most of the code generator was rather straitforeward except a few points: Quasi-paralell Sequencing and Simula's old fashion goto-statement.

I will explain how the new concept of delemitted continuations can be used to implement coroutines and QPS, and, if we have time for it, how Java's exception handling together with byte code egineering can be used to re-introduce goto in the Java Language. An open source project was established creating a full-fledged Simula Implementation
strictly after 'Simula Standard'. See: https://portablesimula.github.io/github.io/

Bio:
Veteran Software Developer, born may 1946. I started as a young student at Norwegian Computing Center in 1967. Worked in Simula implementation teams on various platforms from the very beginning. I had a central role in designing the Portable Simula System in the 70's.

Tromsø

Past meetups

javaBin Online: Pattern Matching & Sealed Classes: Best Features of OpenJDK 17?

javaBin Online: Kontinuerlig Refactoring - Terje Heen

Domain-Driven Design: The Bare Essentials + Microservices - by Andrew Harmel-Law

Simula and Java - two of a kind