Java Annotated Monthly – April 2026

Irina Mariasova

It’s safe to say March was defined by one thing: Java 26. In this issue of Java Annotated Monthly, we’ve curated a rich selection of articles to help you get the full picture of the release. Marit van Dijk joins us as the featured guest author, bringing her expertise to help you navigate the changes with confidence. Alongside our Java 26 coverage, you’ll find our regular roundup of AI developments, Spring updates, Kotlin news, industry trends, and community reads that caught our eye.

Featured Content

Marit van Dijk

Marit van Dijk is a Java Champion and Developer Advocate at JetBrains with over 20 years of software development experience. She’s passionate about building great software with great people, and making developers’ lives easier.

Marit regularly presents at international conferences and shares her expertise through webinars, podcasts, blog posts, videos, and tutorials. She’s also a contributor to the book 97 Things Every Java Programmer Should Know (O’Reilly Media).

March held a lot of interesting things for Java. First of all, there was the Java 26 release on March 17. You can read all about Java 26 in IntelliJ IDEA on the blog, and find more links on Java 26 in the Java sections below.

Also in March, JavaOne took place in Redwood Shores, USA. During the community keynote, our colleague Anton Arhipov talked about 25 years of IntelliJ IDEA. In case you missed it, we also did a Duke’s Corner podcast and a Foojay podcast on the same topic. And of course, the IntelliJ IDEA documentary was released this month. Also at JavaOne, we announced that Koog is coming to Java, if you want to try JetBrains’ Koog AI agent with Java instead of Kotlin.

IntelliJ IDEA 2026.1 was just released. Of course we have Java 26 support from day one, as well as improvements to the debugger for virtual threads, support for new Kotlin features, Spring Data and Spring Debugger features, new AI features, and more. You can read all about it on the blog or watch our release video.

The release of Java 26 also means that Piotr Przybył and I updated our talk, Learning modern Java the playful way, for Java 26. You can watch the recording from Voxxed Days Amsterdam, or catch us at multiple events around Europe. 

Java News

Check out all the Java news highlights in March: 

• Java News Roundup 1, 2, 3, 4, 5
• Java 26: What’s New?
• HTTP Client Updates in Java 26
• Java Performance Update: From JDK 21 to JDK 25
• Quality Outreach Heads-up – JDK 27: Removal of ‘java.locale.useOldISOCodes’ System Property
• Episode 51 “Unboxing Java 26 for Developers” 
• Java 27 – Better Language, Better APIs, Better Runtime
• Foojay Podcast #92: Java 26 Is Here: What’s New, What’s Gone, and Why It Matters in 2026
• Java 26 in definitely UNDER 3 minutes
• JDK 26 Security Enhancements

Java Tutorials and Tips

You can never have too many tips for getting more out of Java:

• Java 26 for DevOps
• Java 26 Is Here, And With It a Solid Foundation for the Future
• Closed-world assumption in Java
• JavaScript (No, Not That One): Modern Automation with Java
• Redacting Sensitive Data from Java Flight Recorder Files
• Foojay Podcast #91: 25 Years of IntelliJ IDEA: The IDE That Grew Up With Java
• Vulnerable API usage: Is your Java code vulnerable?
• Java 26 is boring, and that’s a good thing
• Episode 49 “LazyConstants in JDK 26” 
• Empty Should be Empty
• Testing Elasticsearch. It just got simpler
• A Bootiful Podcast: Cay Horstmann, legendary Java professor, author, lecturer 
• Episode 50 “Towards Better Checked Exceptions” 
• How is Leyden improving Java Performance? 1, 2, 3
• Java Is Fast. Your Code Might Not Be.
• Data Oriented Programming, Beyond Records 
• Evolving the Java Language: An Inside Perspective
• Hybrid search with Java: LangChain4j Elasticsearch integration
• Secure Coding Guidelines for Java
• Estimating value of pi (π) using Monte Carlo Simulation and Vector API
• Javable: generate Java-friendly wrappers for Kotlin with KSP

Kotlin Corner

Stay sharp with the latest Kotlin news and practical tips:

• Kotlin 2.3.20 Released 
• Amper 0.10 – JDK Provisioning, a Maven Converter, Custom Compiler Plugins, and More 
• The klibs.io source repository was made public.
• Building a Deep Research Agent with Koog — Teaching Your Agent to Think in Phases 
• Koog Comes to Java: The Enterprise AI Agent Framework From JetBrains
• Introducing Tracy: The AI Observability Library for Kotlin 
• KotlinConf’26 Speakers: In Conversation with Josh Long 

AI 

Plenty of AI reads this month. Pick what catches your eye:

• Intelligent JVM Monitoring: Combining JDK Flight Recorder with AI
• AI coding skills from the engineers who build the JVM ecosystem
• Vibe Coding, But Production-Ready: A Specs-Driven Feedback Loop for AI-Assisted Development
• Busting AI Myths and Embracing Realities in Privacy & Security
• Shaping Jakarta Agentic AI Together – Watch the Open Conversation
• how i automated my life with mcp servers
• 10 things i hate about ai
• Writing an agent skill 
• Hacking AI – How to Survive the AI Uprising
• Stop Fighting Your AI: Engineering Prompts That Actually Work
• Four Patterns of AI Native Development
• Interactive Rubber Ducking with GenAI 
• The Oil and Water Moment in AI Architecture
• Look Inside a Large Language Model to Become a Better Java Developer
• A Senior Engineer Tries Vibe Coding
• How We Built a Java AI Agent by Connecting the Dots the Ecosystem Already Had 

Languages, Frameworks, Libraries, and Technologies

Spring updates and more tech news, all in one place:

• This Week in Spring 1, 2, 3, 4
• Data Enrichment in MongoDB
• Supercharge your JVM performance with Project Leyden and Spring Boot by Moritz Halbritter
• A Typo Led to the Creation of Spring Cloud Contract • Marcin Grzejszczak & Jakub Pilimon • GOTO 2026
• A Bootiful Podcast: Neo4j legend Jennifer Reif
• A Bootiful Podcast: Spring Messaging Legend Soby Chacko
• Blending Chat with Rich UIs with Spring AI and MCP Apps
• Java Microservices(SCS) vs. Spring Modulith
• Moving beyond Strings in Spring Data
• Quarkus has great performance – and we have new evidence
• Modeling One-to-Many Relationships in Java with MongoDB
• Clean Architecture with Spring Boot and MongoDB

Conferences and Events

Pick your next events to attend:

• Spring I/O – Barcelona, Spain, April 13–15; Come say hi at the JetBrains booth and join the community run! 

• Java Day Istanbul – Istanbul, Türkiye, April 17–18; Anton Arhipov is a speaker.  
• JCON EUROPE – Cologne, Germany, April 20–23; Marit van Dijk will talk about learning modern Java the playful way.
• Great International Developer Summit – Bengaluru, India, April 21–24; Join Siva Katamreddy’s talk on Spring AI + MCP. 
• Devoxx France – Paris, France, April 22–24; Check out the talks by Anton Arhipov and Marit van Dijk.  
• Devoxx Greece – Athens, Greece, April 23–25; Marit van Dijk is a speaker. 
• Voxxed Days Bucharest – Bucharest, Romania, April 28–29; And if you haven’t caught Marit van Dijk during this busy month of hers, here’s the last chance to hear her speak in April.

Culture and Community

Your go-to section to slow down and think about the industry, self-growth, and more:

• Mindful Leadership in the Age of AI
• Can we still make software that sparks joy?
• Information Flow: The Hidden Driver of Engineering Culture
• Beyond the Code: Hiring for Cultural Alignment
• Build a Spaced Repetition Flashcard API with Spring Boot & MongoDB (Part 1)
• Where Do Humans Fit in AI-Assisted Software Development?
• Green IT: How to Reduce the Impact of AI on the Environment
• Does Language Still Matter in the Age of AI? Yes — But the Tradeoff Has Changed
• IntelliJ IDEA: The Documentary | An origin story 
• The Software Architect Elevator 

And Finally…

Top picks from the IntelliJ IDEA blog:

• What’s fixed in IntelliJ IDEA 2026.1
• Java 26 in IntelliJ IDEA
• IntelliJ IDEA’s New Kotlin Coroutine Inspections, Explained
• Cursor Joined the ACP Registry and Is Now Live in Your JetBrains IDE
• Sunsetting Code With Me
• Koog Comes to Java: The Enterprise AI Agent Framework From JetBrains
• AI-Assisted Java Application Development with Agent Skills
• Core JavaScript and TypeScript Features Become Free in IntelliJ IDEA

That’s it for today! We’re always collecting ideas for the next Java Annotated Monthly – send us your suggestions via email or X by April 20. Don’t forget to check out our archive of past JAM issues for any articles you might have missed!