Girls’ Day at the JetBrains office in Munich, Apr 23rd. The registration is open here: www.girls-day.de/.oO/Show/jet...

Today we had a fire alarm in the office. A colleague wrote to a Slack channel 'Fire alarm in the office building', to start a thread if somebody knows any details.

Just seen on a code review: > .groupBy({ it.second }, { it.first }) People may think it's short and concise. I think, it's cryptic and unreadable. You have to go several lines above and find `to` inside one of previous lambdas to finally understand what is `it.first` and what is `it.second`.

Fun with #Kotlin: a pair of parentheses may cost you a lot!

In today crazy #Java series: this code works (with Java 25): <T extends Integer> void test(T t) { t++; //t+=1; IO.println(t); } void main() { test(10); } But if you replace t++ with t+=1, it stops working! Main.​java:3: error: incompatible types: int cannot be converted to T

Had a talk about JSpecify and IntelliJ IDEA on Coffee + Software channel www.youtube.com/live/K9QIYZM...

Nice commit github.com/stack-auth/s...

The IntelliJ IDEA 2025.3 release has landed! This version brings several significant updates, all of which are described and demoed on our What’s New page. Check it out! 👇

@briangoetz.bsky.social are you really this old? 😱

Will you expect this code to be JSpecify-compliant? If not, then how to fix it? @NullMarked public final class Demo { List<String> removeNulls(List<@Nullable String> input) { return input .stream().filter(Objects::nonNull).toList(); } }

Don't miss my new blog post in the Road to GA series to learn how the Spring team empowers Spring developers to make their Spring Boot 4 application null-safe, to reduce or remove the risk of NullPointerException and to solve "the billion dollar mistake"! spring.io/blog/2025/11... #spring #java

A user reports wrong highlighting in IntelliJ IDEA: the code is red, but both javac compiler and ecj compiler compile the code successfully, using any version of compiler. Next you read the spec and realize that IntelliJ IDEA behavior is correct, and both compilers are wrong. Weird feeling.

Days since I mixed 'ExpressionUtils' and 'ExceptionUtils': 0

Is it official now to call the taskbar notification area as 'tray'? I remember Raymond Chen saying that this is wrong 🤔 devblogs.microsoft.com/oldnewthing/...

Fixed a static analysis warning in a Java file in the repo . . . It was a demonstration Java file used to onboard users and teach them about IntelliJ IDEA inspections and quick-fixes. The warning was there to illustrate how inspections work 🤦

TIL: In #Java, List.subList() and List.reversed() are implemented smartly. You may call these methods as many times as you want and in any order, but you don't get a long chain of references which leads to StackOverflowError. The longest chain of views is two: reversed -> subList -> original list.

Implemented Comparator.min/max for the Java standard library. Should be available since Java 26. ❌comp​.compare(a, b) >= 0 ? a : b ✅comp.max(a, b) bugs.openjdk.org/browse/JDK-8...

Java 25 / JDK 25: General Availability: mail.openjdk.org/pipermail/jd... Features: openjdk.org/projects/jdk... Downloads: jdk.java.net/25/ #Java25 #JDK25 #OpenJDK #Java

Java 25 LTS is here! 🚀 Ready to tap into the latest #Java features? #IntelliJIDEA supports Java 25 from day one. Let’s dive into what’s new and how your IDE has you covered! 👇 #Java25IntelliJIDEA jb.gg/r70wns

JetBrains AI Assistant is quite useful for adding Maven dependencies. Take care, though, to update the versions to the latest, as its learning set is somewhat outdated. To update the version, invoke good old code completion.

Looks like today is the day for JDK25! openjdk.org/projects/jdk... #java

Yesterday during dinner with Javazone speakers, I asked JetBrains Kineto to create an app to check whether a number is prime and show factors if it's not. It took a single prompt and about 30 minutes. It deploys the app automatically. Now I have my very own prime checker 😁

Josh's talk was actually very hot 🔥 #JavaZone

🔄 Just starting to explore JSpecify or thinking of migrating from another nullability library? Come chat with @tagir-valeev.bsky.social and the team behind the JSpecify support in IntelliJ IDEA – you’ll find them at the @jetbrains.com booth at @javazone.bsky.social‬ 2025!

Java 24 is three times bigger than Java 8. That's the fact, that's simple math. @starbuxman.joshlong.com on #JavaZone

In person @docker.com help from @shelajev.bsky.social at @javazone.bsky.social - Thank you! #JavaZone

What people see: new modern API to write class files. What I see: missing semicolon at line 8. @rafaelcodes.bsky.social at #JavaZone.

Good morning @javazone.bsky.social 2025! Swing by the @jetbrains.com booth to see what’s new in IntelliJ IDEA 2025.2. 🎤 Don’t miss @maritvandijk.bsky.social’s talk, “Be more productive with IntelliJ IDEA”, at 10:20 am, where she’ll share tips to boost your workflow.

If you like to chat about Java or IntelliJ, catch me near JetBrains booth on #JavaZone.

get! get! get! get! get!!! #Java25

I like how @briangoetz.bsky.social uses type nullability markers ? and ! in an unrelated discussion without even explaining them, like if it's already well-known thing that exists in the language for a long time 🙂

As named constructors are not possible in #Java, some non-public constructors in OpenJDK contain bogus parameter, just to differentiate them from other constructors.

“Sudo, Make Me a Sandwich! – Live Coding With Agentic AI in IntelliJ IDEA” by @antonarhipov.bsky.social is now live: youtu.be/1cx8vDJYi74 Watch Junie, JetBrains’ coding agent, in action and see how far AI can go in dev workflows. #IntelliJIDEAConf

I've wanted to buy "100 Java Mistakes..." by @tagir-valeev.bsky.social for a while. Done 👍. Tagir knows so much about Java, and I'm sure I've made many of these mistakes. I'm looking forward to reading this now. 🙏

Using AI slows down experienced developers? metr.org/blog/2025-07...

Asked JetBrains Junie to implement Stream.takeWhile support in our dataflow analysis. It implemented it, and the tests I wrote beforehand are passed. However, it just reused the Stream.filter implementation. Apparently, I needed better tests. Still, it's a good start, not complete garbage.

If you have a CPU-intensive computation which moves/copies data between HashSets a lot, it may make sense to enumerate all your objects (map them to consecutive integers) and move to BitSets instead, mapping back at the end. They are waaaay faster.

I'm going to visit JVM LS this year! See ya there!

One of my top 3 highlights this year thus far was being invited by the @jetbrains.com @intellijidea.com team to celebrate #30YearsOfJava. The #Java story is rooted in both ongoing technical innovation & community participation. My thanks to @maritvandijk.bsky.social who made this all possible.

#Java peers...the 2025 @intellijidea.com Conference is around the corner (June 3-4)! There's still time to register for this FREE virtual event: jb.gg/c463w8 Hear from host @maritvandijk.bsky.social and me as we kick things off to celebrate 30 YEARS OF JAVA!

TIL: In #Java format strings, you can specify indentation to a single percent character.

Kinda cool #Java30Years #JetBrains www.youtube.com/watch?v=kHyb...

Here's how the analytics for a single flaky test looks like inside the IntelliJ project.

Manchmal sind es die kleinen Dinge, die einem das Leben versüßen oder auch 100. @bahn.de @tagir-valeev.bsky.social

🤗 Mellum is now open source on @hf.co! It’s a focal model that is small, efficient, and made for one thing: code completion. ⚙️ Trained from scratch by JetBrains. 🌱 First in a growing family of dev-focused LLMs. 🔗 jb.gg/hi_mellum

The correct answer is counter-intuitively, Outer2​.foo. Normally, classes and variables have separate namespaces in Java, so importing class and importing variable (static field) with the same name does not produce an ambiguous import.

Ok, here's my solution. Full of warnings, of course, but who cares about warnings? void main() { O<O<O>> O = O<O>::<O>O; } interface O<T> { void use(O c); default <C> void O() { } }

Provide the declaration of the O type, so this statement could be a valid #Java statement: O<O<O>> O = O<O>::<O>O;

Well, I didn't fall for Mistake #11 from @tagir-valeev.bsky.social's book, but quite something similar: Jackson Objects are both mutable AND return the updated self. I took it for being a copy-then-modify-Operation and used the original value elsewhere - which was modified, too. 😬 #java #mistakes

What is the output of the following Java code? A: Outer.Inner​.foo B: Outer2​.foo C: Compilation error D: Runtime exception (No idea if it's possible to post a poll here)