Joris Kuipers @joris.kuipe.rs · 28/09/2026TIL that Spring's RestClient does not automatically add an Accept header to its requests like RestTemplate does. We have migrated a lot of clients already, but only now encountered the first backend that compained about a missing Accept header. 020
Joris Kuipers @joris.kuipe.rs · 22/09/2026In the process of migrating a huge monorepo using 1000s of lines of code with Spring's RestTemplate to use RestClient. It's an easy mistake to leave an existing HttpEntity that was passed as the request to the template and now pass it to the RestClient's body() method: still compiles, but wrong. 100
Joris Kuipers @joris.kuipe.rs · 15/09/2026JFC, working with GraalVM is worse than getting your OSGi bundles to run with Spring 15 years ago: java.lang.IllegalArgumentException: Invalid logger interface org.hibernate.validator.internal.util.logging.Log (implementation not found) Supposedly fixed, but not for me: github.com/oracle/graal...github.comCaused by: java.lang.IllegalArgumentException: Invalid logger interface org.hibernate.validator.internal.util.logging.Log (implementation not found in jdk.internal.loader.ClassLoaders$AppClassLoader@2...Hi, I am having an issue mentioned below while running the artifact using nativeRun. (nativeCompile worked properly) Caused by: java.lang.IllegalArgumentException: Invalid logger interface org.hibe... 000
Joris Kuipers @joris.kuipe.rs · 15/09/2026AI might kill us all, but let’s see if it can debug why my GraalVM build stopped working with Thymeleaf after updating from Boot 3.5 to 4.1.1 and then let’s see what I need to worry about first. 100
Joris Kuipers @joris.kuipe.rs · 05/09/2026Black Keys in Amsterdam tonight, with localized drums 🥁 020
Joris Kuipers @joris.kuipe.rs · 02/09/2026My presentation from this year’s Spring I/O conference is up on YouTube: if you’re using point-to-point messaging, make sure to check it out for some production-hardened ideas on how to handle dead-lettered messages for your applications and platforms! 📨🍃 010
Reposted by Joris KuipersWim Deblauwe @wimdeblauwe.com · 19/08/2026📕 I just published my new book Crafting Spring Boot Starters, see www.wimdeblauwe.com/books/crafti... if you are interested! There is a free sample you can check out where you can read the foreword by Phil Webb. The full book also has a zip file with AI skills to audit your Spring Boot starter.wimdeblauwe.comCrafting Spring Boot StartersDesign, build, test and publish auto-configuration libraries on Spring Boot About the book ... 132
Joris Kuipers @joris.kuipe.rs · 20/07/2026Was expecting a little Andrew Tanenbaum figurine #disney #disappointed #ast 000
Joris Kuipers @joris.kuipe.rs · 02/06/2026Now let's see if this thing will deploy :) @spring.io Boot 4 / Framework 7 upgrade with Jackson 3 on 3 dozen microservices 110
Joris Kuipers @joris.kuipe.rs · 29/05/2026No one doing this already? Is using virtual threads in production really pioneering? 110
Joris Kuipers @joris.kuipe.rs · 29/05/2026If you think Europe’s GDPR is a bitch, read what & how the American government is actually collecting on its citizens and then we can talk again. 000
Reposted by Joris KuipersThomas Vitale ☀️ @thomasvitale.com · 20/05/2026It was really exciting to officially introduce Arconia at Spring I/O last month. Open-source extension improving the developer experience on Spring Boot. I talked about dev services, observability, automated migrations, agent skills, and a sneak peek at the upcoming dev UI. @arconia.io 012
Joris Kuipers @joris.kuipe.rs · 08/05/2026Planning to use virtual threads with Spring Boot. Means server.tomcat.max-threads will be ignored and server.tomcat.max-connections will effectively determine concurrency, but that's for capping open connections, not actively handled requests. Should I add a semaphore to control concurrency myself? 010
Joris Kuipers @joris.kuipe.rs · 30/04/2026Just silently broke my Logback-based logging when updating a GraalVM natively compiled Spring Boot app from 3.5.8 to 3.5.14. Goes to show that this is still really tricky to use and not really ready for mass enterprise adoption, as far as I'm concerned. 110
Joris Kuipers @joris.kuipe.rs · 28/04/2026No better way to get over your King’s Day hangover than some Belgian beer & boogie with Triggerfinger in Paradiso 🎸 000
Reposted by Joris KuipersYuriy @yuriy-artamonov.bsky.social · 25/04/2026Want fewer freezes and bugs in your IntelliJ IDEA? Help us — enable automatic error reporting: Appearance & Behavior → System Settings → Data Sharing → Send error reports automatically Every report helps prioritize fixes. Takes 10 seconds, makes a real difference! #ide #java 032
Joris Kuipers @joris.kuipe.rs · 17/04/2026Second time I’ll watch this band which I’d never thought I’d be able to see live some years ago! 000
Joris Kuipers @joris.kuipe.rs · 16/04/2026US citizens actually voted for this con man (and his relatives) 🤦♂️ gothburz.substack.com/p/these-even...gothburz.substack.comThese Events Are UnrelatedFour crypto products, three pardons, and $1 billion extracted in 18 months. A Web3 Ambassador opens all 13 columns of the WLF dashboard. Every number sourced. Every event unrelated. 100
Joris Kuipers @joris.kuipe.rs · 15/04/2026Leaving Barcelona after another great @springio.net edition. Glad that I could speak again, very happy to have reconnected with so many people and hope to be at #springio27 that will take place in Valencia! 😎 Thanks to @sergialmar.com and everyone else who made this happen 🙏 #springio26 081
Joris Kuipers @joris.kuipe.rs · 15/04/2026It’s sorta shocking how many people just don’t care about X and Musk and keep posting there. Here’s another thing that might make you change your mind: cybernews.com/tech/x-shado...cybernews.comCourt orders X to give a shadowbanned user the data it has on himThe Amsterdam court ordered X to grant Dutch national Danny Mekić access to the data the platform holds on him, after he was shadowbanned without a clear explanation or notification. 100
Joris Kuipers @joris.kuipe.rs · 15/04/2026Watching @thomasvitale.com explain his Arconia framework for @spring.io development: very cool, will definitely give this a try. Community hero! 🦸♂️ #springio26 141
Joris Kuipers @joris.kuipe.rs · 14/04/2026Google Maps combined with Barcelona public transport really makes it easy to get around. Hadn’t used Maps for this much yet, but have to admit that I’m impressed with the experience #springio26 110
Joris Kuipers @joris.kuipe.rs · 14/04/2026Home is where the wifi autoconnects: #springio26 may be in a new location, but phone already feels right at home 020
Joris Kuipers @joris.kuipe.rs · 13/04/2026Starting my trip to Barcelona for @springio.net, really looking forward to reconnecting with everyone! If you’re attending: I will be speaking on DLQ management for large scale systems on Wednesday, so consider to join me 2026.springio.net/sessions/fal...2026.springio.netSpring I/O • 13-15 • April • Barcelona 2026 040
Joris Kuipers @joris.kuipe.rs · 12/04/2026Take me to church: guitar ensemble at the ANNA church in Amstelveen 000
Joris Kuipers @joris.kuipe.rs · 10/04/2026Now playing: youtu.be/1LkYJl5EdNY?...youtu.beVulfpeck Live at Red RocksYouTube video by Vulf 000
Joris Kuipers @joris.kuipe.rs · 04/04/2026I see quite some usage of JSON-RPC lately, esp. in AI. Is there some support in the Spring ecosystem for this already? I'm thinking about routing/mapping to handlers, error handling and esp. metrics since editing HTTP metrics are useless b/o the single endpoint. 110
Joris Kuipers @joris.kuipe.rs · 04/04/2026Cool to read how @springio.net has real-world impact: medium.com/graalvm/insi... 073
Joris Kuipers @joris.kuipe.rs · 02/04/2026Even Josh and James are in awe when Venkat demos Kotlin in vi while talking as if he was a one-man band #vdams26 010
Joris Kuipers @joris.kuipe.rs · 02/04/2026“Ik hoop maar dat er roze koeken zijn” youtu.be/F3ZTrGWSLf4?... #dvams26 010
Joris Kuipers @joris.kuipe.rs · 01/04/2026Alina explaining how GraalVM will focus on AI after Oracle just laid off 30.000 colleagues to pay for those investments is a bit hard to watch. Obviously she is handling it very professionally, but I can’t help thinking about how it must feel to sit there presenting at a time like this… 🫶 #vdams26 020
Joris Kuipers @joris.kuipe.rs · 01/04/2026Spring-AI deep-dive by @tzolov.bsky.social at #vdams26. Fast-paced with lots of info, at the same time slowly building up to show how all features are based on a small nr of core principles and techniques, very nice! 041
Joris Kuipers @joris.kuipe.rs · 31/03/2026So Anthropic engineering interviews will now ask “what would YOU improve in our Claude Code code base” as an assignment 120
Reposted by Joris KuipersBert Hubert 🇺🇦🇪🇺🇺🇦 @berthub.eu · 29/03/2026En het parlement biedt uiteindelijk nooit tegenwicht. Want kabinet zegt dat ze het heel zorgvuldig gaan doen met de beste regels. Als parlement kun je dan of zeggen "nietus, dat doen jullie helemaal niet", of je kunt meedoen: alles voor de veiligheid! Zie ook mijn stuk berthub.eu/articles/pos...berthub.euData en de Democratische Rechtsorde - Bert HubertData en de democratische rechtsorde. Ik dacht, ik begin eens goed pompeus. Bij de AIVD werkte ik mee aan het afluisteren van mensen, later heb ik daar software voor gemaakt en allemaal heel interessan... 24331
Joris Kuipers @joris.kuipe.rs · 13/03/2026First blog post of the year is out: Fault Injection with @spring.io using @micrometer.io Baggage Propagation. If you're building complex orchestration flows with Spring and looking for a way to test non-happy flows, this one is for you! trifork.nl/blog/fault-i...trifork.nlFake It Till You Make It: Fault Injection with Spring using Headers and Baggage Propagation - Trifork BlogAt Trifork, we build custom software that powers the core business of many clients. For Nederlandse Loterij we’re developing an integration platform that handles, among many other use cases, the purch... 010
Joris Kuipers @joris.kuipe.rs · 08/03/2026Spring cleanup (although I’m keeping my old Spring books) 010
Reposted by Joris KuipersSpring I/O @springio.net · 04/03/2026Standard tickets are almost SOLD OUT. 🎟️ Get yours before prices go up! 2026.springio.net 043
Joris Kuipers @joris.kuipe.rs · 04/02/2026Learned that Spring RestClient.Builder is stateful and passes state like interceptors by ref on build. That means that this creates clients with both *two* interceptors: var first = builder.requestInterceptor(someInterceptor).build; var second= builder.requestInterceptor(someInterceptor).build; 100
Reposted by Joris KuipersJoris Kuipers @joris.kuipe.rs · 05/12/2025To my fellow European techies: why do you still think it’s OK to speak at American conferences? At this point, isn’t it completely obvious that you’re traveling to a country led by a corrupt and fascist regime that needs be boycotted? 242
Reposted by Joris KuipersJoris Kuipers @joris.kuipe.rs · 23/01/2026God forbid that there’s a plan 121
Joris Kuipers @joris.kuipe.rs · 15/01/2026Half my timeline is now about AI while the other half shows the US Gestapo in near-real time action. Too fucking unreal, I need to go offline more to stay sane. 040
Joris Kuipers @joris.kuipe.rs · 09/01/2026New Year’s resolution: listen more John Butler Trio. Weird how I’ve mostly missed them before. 000
Joris Kuipers @joris.kuipe.rs · 19/12/2025Here we go 🤞 As always for @spring.io, this would be a brand new talk. I've meaning to write or talk about this solution for some years already, so hopefully I'll be able to finally share what we've developed for DLQ management with the whole community in Barcelona next year! 🍃 140
Joris Kuipers @joris.kuipe.rs · 10/12/2025So fucking predictable news.sky.com/story/us-pla...news.sky.comUS plans to start checking all tourists' social mediaThe potential social media mandate being proposed by Customs and Border Protection (CBP) would apply to anyone visiting, whether they require a visa or not. 000
Joris Kuipers @joris.kuipe.rs · 09/12/2025Don't know why yet, but turns out that running a Spring Boot app using virtual threads on OpenJ9 24 or 25 in a Linux container results in continuous high CPU load, which did NOT occur on their 21 JVM. Starting investigation, but all clue suggestions are welcome! 210
