CERN JUG Meet-up #2 - Spring Boot: Chapter 4

Tuesday 4 Nov 2025, 18:30 → 19:20 Europe/Zurich

500/1-001 - Main Auditorium (CERN)

Welcome to the CERN Java User Group Meet-up #2: Spring Boot: Chapter 4

This event offers a unique opportunity to those passionate about Java and modern engineering practices to engage with the CERN developer community and beyond. Whether you are a CERN member or an external visitor, we invite you to join us for an evening of learning and networking.

• Registration: To subscribe to news about future events and meetups, please use the CERN JUG mailing list. Those of you coming from the outside of CERN will need to create a guest account as explained here.

• External visitors: If you are coming from outside CERN, we will arrange a badge for you upon registration. Badges are necessary for site access and will be printed for your convenience.

• Date & Time: 04 November 2025, 18:30–19:20

• Venue: Room 500/1-001, CERN

 

For any questions, please contact the organizing team at cern-jug-organizers@cern.ch.

 

 

1 Spring Boot: Chapter 4

Spring Boot 4.0 is scheduled for November. While the Java baseline remains at 17, it’s the perfect time to leverage new language and framework features. Stéphane and Brian will start by upgrading their existing application to Spring Boot 4.0.

Along the way, we will prevent future NullPointerExceptions in production thanks to Nullness metadata in Spring projects and JSpecify Nullability checks. We will also revisit our application dependency arrangement: Spring Boot now provides fine-grained dependencies that allow for more flexibility in your application. The new Jackson 3.0 integration simplifies our Jackson setup and updates configuration options with more modern opinions. We will also see how we can use a RestClient in asynchronous scenarios without involving Reactive types.

Speakers: Mr Brian Clozel (Spring Team), Mr Stéphane Nicoll (Spring Team)