Cay Horstmann
@horstmann.com
📤 335
📥 265
📝 31
Nothing to see here...keep moving! Specifically, to Mastodon:
https://foojay.social/@cayhorstmann
Here is my "Java Advent" article on nice and naughty cases of pattern matching, with nicer formatting than WordPress can muster, and the ability to leave comments without logging into WordPress:
https://horstmann.com/un...
18 days ago
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I participate in Advent of Code
(https://adventofcode.co
) to learn, and today I learned plenty. My naĂŻve brute force solution for Day 8 required 3 minutes. I re-learned the union-find algorithm (never touched it since grad school, 45 years ago), and am down to < 1 sec.
https://github.com/cayho...
20 days ago
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My article "Nice and Naughty Cases of Pattern Matching" has been published in the JVM Advent Calendar:
https://www.javaadvent.c...
21 days ago
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This year’s JVM Programming Advent Calendar is open for business at
https://www.javaadvent.c...
Every day, a new post awaits. I enjoy this eclectic overview of what is new in the Java ecosystem.
27 days ago
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There is always more to learn about Unicode. Today I found out about the aptly named WTF encodings:
https://wtf-8.codeberg.page
Java strings are actually WTF-16, not UTF-16. For example, the Java string "WTF\uD800" is not valid UTF-16.
28 days ago
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Help--my LocalDate isn’t flattened! Just before my Valhalla talk at JFall, I found out that the early access build can flatten LocalDate arrays, but the latest version from Github cannot. Why? Serialization, of course. Read the gory details at
https://horstmann.com/un...
about 2 months ago
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On Thursday November 13, I will speak in Berlin on "Virtual Threads—A Second Look".
https://www.meetup.com/j...
about 2 months ago
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As I am updating my slides, another shoutout to
https://imagetodrawio.com
I upload a hand-drawn diagram and get something that I can clean up in
draw.io
Final result:
https://horstmann.com/pr...
That is how AI should be. Human in the loop. Tweakable result without endless prompting.
about 2 months ago
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I'll be speaking at JFall on project Valhalla on November 6.
https://jfall.nl
about 2 months ago
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Core Java 14th edition, updated for Java 25, is now available in print or ebook at
https://www.informit.com...
and
https://www.informit.com...
3 months ago
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The latest Maven exec plugin can execute "instance main methods":
https://horstmann.com/un...
3 months ago
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I will give two talks at BED-Con 2025
(https://bed-con.org/202
) on October 7 and 8 in Berlin.
3 months ago
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After more than a year of trying off and on, I finally managed to fix my Emacs/LSP/Java setup. Now I can happily edit my Java scripts in Emacs instead of VS Code. Details at
https://horstmann.com/un...
3 months ago
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My take on Java 25:
https://horstmann.com/un...
3 months ago
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Following a suggestion from Stuart Marks
(https://stuartmarks.wor...
, I add JavaDoc as a search engine to my browser. I just updated the search URL to
https://docs.oracle.com/...
3 months ago
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$ java -version openjdk version "25" 2025-09-16 LTS Remarkably, the four numbers are perfect squares: 5², 45², 3², and 4².
3 months ago
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SKDMAN! has the first Java 25 JDK that is not an “early access” release: $ sdk install java 25-zulu Done installing! Do you want java 25-zulu to be set as default? (Y/n): y
3 months ago
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Next Tuesday, I'll be talking about benchmarking Project Valhalla at the Java Forum Nord in Hannover
https://javaforumnord.de...
4 months ago
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I returned from the amazing JavaZone conference in Oslo. My talks at
https://2025.javazone.no...
and
https://2025.javazone.no...
Videos of many other great presentations already available at
https://2025.javazone.no...
4 months ago
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For anyone with an
oreilly.com
subscription: "Early release" versions of the 14th edition of Core Java are at
learning.oreilly.com/library/view...
and
learning.oreilly.com/library/view...
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O'Reilly Media - Technology and Business Training
Build the skills your teams need. Give them the O'Reilly learning platform and equip them with the resources that drive business outcomes.
https://oreilly.com
4 months ago
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Two years ago, fed up with Google, I switched to Kagi search. Their secret sauce: Downrank pages filled with ads. Works for me. Just got a jubilant announcement--they reached 50K paying customers (
blog.kagi.com/50k
) Really??? 50K paying customers and their results beat Google. There is hope.
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Celebrating 50K users with Kagi free search portal, Kagi for libraries, and more... | Kagi Blog
Just last week, we celebrated three years since Kagi was launched.
https://blog.kagi.com/50k
6 months ago
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Puzzler of the week: Which of these are valid Java variable declarations? [ ] short euro€; [ ] double world世界; [ ] long wavy﹏; [ ] char bell\u0007; To vote, go to
foojay.social/@cayhorstman...
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Cay Horstmann (@
[email protected]
)
Puzzler of the week: Which of these are valid Java variable declarations? [ ] short euro€; [ ] double world世界; [ ] long wavy﹏; [ ] char bell\u0007;
https://foojay.social/@cayhorstmann/114652651018133021
7 months ago
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I'll be speaking at the OpenValue Meetup in DĂĽsseldorf May 22 18:00. "When to Stream, Collect, and Gather".
www.meetup.com/openvalue-du...
.
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When to Stream, Collect, and Gather & Demystifying Dependency Injection, Thu, May 22, 2025, 6:00 PM | Meetup
**Dear Java Community,** **After the meetup is before the meetup!** We’re excited to invite you to the next **OpenValue Meetup** on **May 22nd** in Düsseldorf! Once agai
https://www.meetup.com/openvalue-dusseldorf/events/307560744
7 months ago
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Finally recovering from JCON in Cologne. Great conference! I gave two well-attended talks.
horstmann.com/presentation...
horstmann.com/presentation...
Keynote surprise: I got a "Java Community Lifetime Achievement" award. For having survived 30 years of Java. Looking forward to many more years...
8 months ago
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On April 24, I'll talk about Benchmarking Project Valhalla at the JUG Darmstadt:
www.jug-da.de/2025/04/Benc...
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Benchmarking Valhalla (Java Value Types) | Java User Group Darmstadt
Abstract Project Valhalla introduces value types into the Java language and virtual machine. Value types can be more efficient since they do not need pointer indirection and heap allocation. Moreover,...
https://www.jug-da.de/2025/04/Benchmarking-Valhalla/
8 months ago
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Trip report from Java One...but not the usual kind
www.travelblog.org/north-americ...
9 months ago
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For anyone teaching Java: I posted a quick summary of new Java features that help beginners.
horstmann.com/unblog/2025-...
10 months ago
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Hands-on experience with DeepSeek:
horstmann.com/unblog/2025-...
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Cay Horstmann’s Unblog
https://horstmann.com/unblog/2025-01-25/index.html
11 months ago
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I'll be talking at the free online jChampionsConference today at 16:00 UTC on "Java for Small Coding Tasks". Register at
jchampionsconf.com
11 months ago
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In this final article on my experience with the Advent of Code competition, I describe how I attacked grid and graph problems, and summarize how Java has worked out for me.
horstmann.com/unblog/2024-...
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Cay Horstmann’s Unblog
https://horstmann.com/unblog/2024-12-26/index.html
about 1 year ago
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