New candidate JEP: 534: Compact Object Headers by Default: https://openjdk.org/jeps/534 #openjdk #java

Do you feel like my latest Leyden blog post about the AOT Cache in Java was too heavy?

Don't worry, I have a shorter version: https://developer.ibm.com/articles/java-project-leyden/

#Java #OpenJDK #Leyden #AOTCache #Performance #Optimization

Elegant Design Principles by Narayanan Jayaratchagan is free with a Leanpub Reader membership! Or you can buy it for $19.00! https://leanpub.com/elegant_design_principles_fsd #ObjectOrientedProgramming #ComputerProgramming #Java #SoftwareArchitecture #FunctionalProgramming

Enum Hashes

FreshMarker is based on the concepts of another template engine. This is evident from its directives, interpolations, and, of course, its name. Another detail also betrays its origins. The types in the FreshMarker Template Language for collections are sequences and hashes. Hashes represent mappings from strings to values. We now want to rel

https://schegge.de/2026/04/enum-hashes/

#Bibliotheken #FreshMarker #Java #Refactoring #Enum #FreshMarker #Template #TemplateEngine

Here is the new #JavaFX #LinksOfTheWeek, published on https://www.jfx-central.com/links.

Thanks to
No-Security-7518
@leewyatt
@dlemmermann
Hidekazu Kubota
Daniel Harris

Happy reading, and have a lovely #Java weekend!

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OpenJDK Interim Policy on Generative AI

https://openjdk.org/legal/ai

#OpenJDK #Java

So, #Microsoft says Co-Pilot is a tool for entertainment and the other #AI company nobody talks about sounds like this

> Generative AI tools, by their nature, make it easy to create large quantities of plausible-looking code, with plausible-looking tests, which is nonetheless incorrect or, even if it is correct, is poorly designed and therefore difficult to maintain.

This is from #Oracle in there “OpenJDK Interim Policy on Generative AI”

https://openjdk.org/legal/ai

#OpenJDK #Java #Doppeldenk

Refactoring Java just got smarter 🤖

At #ArcOfAI, Venkat Subramaniam shows how to use AI and data-driven techniques to modernize code—measuring quality before and after for real impact.

https://www.arcofai.com/speaker/7e0794827e8242ef8464e383e1209fad

🎟️ Get tickets: https://arcofai.com

#Java #AI #DevTools #Refactoring #AIEngineering #GenAI #Austin #AustinTech

I'll be doing some of the work on my live coding stream on Fridays, starting April 10th at 12pm PDT (7pm UTC). That'll be a short, 1-hour stream, due to other commitments. Future streams will be ~3 hours and you'll be able to AMA on #Java, #Spring, etc.

https://jitterted.stream/

A Short Guide to Naming by Tim Ottinger is free with a Leanpub Reader membership! Or you can buy it for $5.00! https://leanpub.com/naming_shortguide #ComputerProgramming #Python #Javascript #Java #WebDevelopment #Refactoring

@xilerk Good catch! This command did the trick:

$ mvn -D versions.outputLineWidth=${COLUMNS} versions:display-dependency-updates

Of course, ${COLUMS} could be set to some arbitrary huge value to help better ensure single line per dependency.

Thanks a bunch for the suggestion! :-)

#Maven #Java #Programming

This is not easily parsed by machines (or even humans). Some version numbers are on the same line, others are on a separate line.

There's extraneous and unneeded info.

And there's no way to influence the appearance of the output. For example, the ps command as the -w flag to explicitly set wide text output mode.

#Maven #Java #Programming

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Screenshot of `mvn versions:display-dependency-updates`

My Java Modules with @ASFMavenProject (4) series continues!

Cleanly separate API and implementation in Java modules — and why mixing both is a common antipattern.

https://maven.aschemann.net/blog/2026/03/26/api-and-implementation/

#Java #Maven #JavaModules #ApacheMaven

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Blog Series about Java Modules with Maven 4: "Separating API and Implementation" — using dedicated modules and requires transitive in Java Modules with Maven 4. With a portrait of the author.

EqualsVerifier 4.4.2 is out! It's a bugfix release that improves the layout of error messages, fixes a small bug with Kotlin lazy fields, and fixes two other minor issues.

Check it out: https://github.com/jqno/equalsverifier/blob/main/CHANGELOG.md

#java

Another stream, another set of notes. So much "new"!

I try out a new design for Projectors, splitting EventConsumer into two pieces. Test-driving shows how it's about design exploration, not just writing tests.

https://ted.dev/articles/2026/04/06/live-coding-journal-apr-6-2026/

#Java #EventSourcing #TDD

I love working with #Java.

I wanted to upgrade the app runtime from 17 to 21 - all I needed to do was install the new runtime, change the java.version property to 21, rebuild, and deploy.

And that is all - everything is working perfectly 😍

Notes from my #Java #EventSourcing work, where I looked at event consumers that only get events they're interested in.

Struggled with Java's MethodHandle (docs could be better!), but otherwise works well.

Thoughts about Projector design.

Read more at: https://ted.dev/articles/2026/04/02/live-coding-journal-apr-2-2026/

Here is the new #JavaFX #LinksOfTheWeek, published on https://www.jfx-central.com/links.

Thanks to
PDFSam
@dlemmermann
@hansolo_
@foojay

Happy reading, and have a lovely #Java weekend!

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I wrote an article for JAVAPRO about the Foreign Function and Memory (FFM) API, added in #Java 22, and how it got used to add a new and better plugin to @pi4j

You can read it here:
https://javapro.io/2026/04/01/the-ffm-api-openjdk-changed-the-game-for-native-interactions-and-javaonraspberrypi/

#JavaOnRaspberryPi

People keep asking me about these badges…
especially the ribbons.

Yes, there’s a bit of “catch ’em all” 😄
But they actually do something simple: they start conversations.

You see a topic → you talk → something interesting happens.

That’s the real value of in-person conferences.

That’s what JCON EUROPE 2026 is about.

Join us in April in Cologne: https://2026.europe.jcon.one/

#Java #JCON #Community

This was all triggered by new functionality that I want to add: the ability to set a date/time when concert tickets go on sale that is separate from when the concert was scheduled (entered into the system).

Read all about it at https://ted.dev/articles/2026/03/30/live-coding-journal-mar-30-2026/

#EventSourcing #Java

#Oracle zeigt heute mal wieder, was ihnen die #Java Community bedeutet, hm?

https://youtube.com/shorts/zvmxZYIA13Q

Project #Leyden Project #Valhalla #OpenJDK
And most importantly: The people behind it.

Sharat Chander invites you to meet #Oracle, top speakers and the global #Java community at #JCON2026.

🎟️https://2026.europe.jcon.one/tickets

Want some Technical Coaching or a #Java Talk (Event-Sourcing, Testing)?

I'm looking to do meetup/user group presentations or technical coaching the week of April 27, and in June so I don't have to fly all the way back home, just to fly back again a soon after.

I've released the Distributed Systems Simulator v1.1.0! https://foo.zone/gemfeed/2026-03-31-distributed-systems-simulator-part-1.html - It now also can simulate the Raft consensus protocol! #java #distributedsystems #raft #raftconsensus #simulator #release

I love #Java generics (when I get them right, which can take me a while!) and find varargs really useful when refactoring, but they do NOT play well together. Ugh. Guess I'll create an overloaded method to take a List<T> instead.

On my #Java stream last week, I had some frustration with Avro for event payload serialization and decided that JSON was just fine (in terms of performance).

I had thoughts about Projections as Caches and a question around IDs being required in events.

https://ted.dev/articles/2026/03/25/live-coding-journal-mar-25-2026/

#Lisp people, do you have a preference for the name 'hashtable' or 'hashmap'? In #Java, there's an actual semantic difference, since Java HashTable is not thread safe while Java HashMap is.

I am building things which are thread safe. My inclination is to call them 'hashtables', but is this now old fashioned and should 'hashmap' be preferred?

If so, please give reasons.

Here is the new #JavaFX #LinksOfTheWeek, published on https://www.jfx-central.com/links.

Thanks to
Kevin Rusforth
@APIdia
@gluonhq
@eitch
@lottie4j
@dlemmermann
Lee Wyatt

Happy reading, and have a lovely #Java weekend!

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Big Kotlin pack by Marcin Moskała is the featured bundle on Leanpub!

Link: https://leanpub.com/b/kotlin_mm

#Kotlin #Android #Java #ComputerProgramming #Engineering

Spring Boot 4.0.5 available now

#java #springboot #springframework

https://spring.io/blog/2026/03/26/spring-boot-4-0-5-available-now

More live coding #Java and #EventSourcing:

I dealt with "external" and "parameter" validation (I didn't implement the third type: "internal" validation) of scheduling conflicts for Concerts.

I also pondered minimal consistency boundaries.

Notes are at: https://ted.dev/articles/2026/03/24/live-coding-journal-mar-24-2026/

Back to streaming, with notes from yesterday's stream: https://ted.dev/articles/2026/03/23/live-coding-journal-mar-23-2026/

I chatted about consistency boundaries, missing-event heuristics, and encoding (serializing) events.

#EventSourcing #Java #TDD

The Scripting Dilemma If you're like me, as a Java developer, you struggle to remember bash or python syntax for quick scripts. You end up "vibe coding" it, then struggle again when you need to adapt it. If only you could write it in Java! You might say "Java is not for scripting" and "I…...
#CLIscript #Java #Javascripting #JBang #PicoCLI #script
https://foojay.io/today/java-for-scripting/

Stratospheric - From Zero to Production with Spring Boot and AWS: Hands-on online course to learn all you need to know to get a Spring Boot application into production with AWS. by Philip Riecks, Björn Wilmsmann, and Tom Hombergs is the featured course on Leanpub!

Link: https://leanpub.com/courses/leanpub/stratospheric

#AmazonWebServices #Java #SoftwareArchitecture #SoftwareEngineering #CloudComputing

Here is the new #JavaFX #LinksOfTheWeek, published on https://www.jfx-central.com/links.

Thanks to
@gluonhq
@johanvos
#Oracle
@eitch
@rladstaetter
Pavel Castornîi
Helal Anwar
Florian Enner
JPro

Happy reading, and have a lovely #Java weekend!

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CAS Internals: A Journey Through the Central Authentication Server Codebase by Dmitriy Kopylenko is the featured book on Leanpub!

Link: https://leanpub.com/cas-internals

#ComputerProgramming #SoftwareArchitecture #Java #ComputerSecurity #SoftwareEngineering