OpenJDK's Project Valhalla is improving Java's support for custom numerical types. That goes beyond value types and also encompasses explorations into operator support. While Java is extremely unlikely to ever allow arbitrary operator definitions, it may well support limited operator overloading, so custom value types could be added or multiplied with plus or multiplication signs instead of annoying method calls. In this "Ask the Architects" episode of the Inside Java Podcast, recorded during JavaOne 2026, Nicolai Parlog talks to Joe Darcy, Valhalla committer in the Java Platform Group at Oracle. "Ask the Architects" is our podcast show, where we talk to experts in OpenJDK about their work on the Java language, API, and runtime.

Aug 20

34 min

JEP 540 proposes to incubate a simple JSON API and is currently proposed to target JDK 28. The pull request for Project Valhalla's JEPs 401 and 539 were merged and value types are available as a preview feature in the latest JDK 28 early-access builds. Oracle plans to backport post-quantum cryptography to Oracle JDKs with LTS (25, 21, 17, 11, and 8) and move Java to monthly security updated (currently quarterly). JDK 28 EA builds: https://jdk.java.net/28/ Dan's mail re values: https://mail.openjdk.org/archives/list/core-libs-dev@openjdk.org/thread/Y72NRXM7KYBX43OKYBQMVKOZDWKG4MHS/ Angelos' mail re primitive patterns: https://mail.openjdk.org/archives/list/amber-spec-experts@openjdk.org/thread/WSXW4QMJ3EBIHIULEB25HUAMR5JB767H/ JEP 540: https://openjdk.org/jeps/540 JEP 496: https://openjdk.org/jeps/496 JEP 497: https://openjdk.org/jeps/497 JEP 572: https://openjdk.org/jeps/572 Blog post in PQC in LTS: https://blogs.oracle.com/java/post-quantum-cryptography-in-long-term-support-jdk-releases Accelerated Vulnerability Detection and Response: https://blogs.oracle.com/security/accelerating-vulnerability-detection-and-response-at-oracle More frequent Oracle JDK releases:  https://blogs.oracle.com/java/transitioning-java-to-more-frequent-security-updates More Frequent OpenJDK releases: https://mail.openjdk.org/archives/list/jdk-updates-dev@openjdk.org/thread/SVHDNJDY62MX6YBEA4FSMW4U72H77F6S/ JDK 27 RC pushed back: https://mail.openjdk.org/archives/list/jdk-dev@openjdk.org/thread/EYKJPUAZ4BX4DXD7H4C5ETWJFNQZBFO5/ OpenJDK Mail Search: https://openjdk.barlasgarden.com/ 

Helidon 4.4 was released in April 2026 and stands out from other web frameworks by embracing new Java features as early as possible, particularly virtual threads and ahead-of-time computation. It is also aiming to become an OpenJDK project in the coming months. In this "Input/Output" episode of the Inside Java Podcast, recorded during JavaOne 2026, Nicolai Parlog talks to Joe Di Pol, Lead Principal Platform Software Engineer at Oracle where he works on Helidon. "Input/Output" is our new show, where we talk to people outside of OpenJDK to bring you their perspectives and insights into what's happening in the Java ecosystem.

While Java programs are deployed as bytecode, performance-relevant code will be compiled, at run time, to machine code whose performance rivals that of any other platform. In the HotSpot JVM, this is the job of the just-in-time compilers C1 and C2 and between speculation and traps, inlining and constant folding, escape analysis and scalar replacement (and many more), they apply a number of heuristics, analyses, and transformations to achieve that. This requires expertise, careful research, thorough testing, and regular reevaluations of old assumptions. In this "Ask the Architects" episode of the Inside Java Podcast, recorded during JavaOne 2026, Nicolai Parlog talks to Roberto Lozano, compiler engineer at the Java Platform Group at Oracle. In our show "Ask the Architects", we talk to experts in OpenJDK about their work on the Java language, API, and runtime.

Spring AI 2.0 released in June 2026 and is one of several projects ensuring Java's continued strength in enterprise AI development. Here are some tips on deterministic agents, MCP servers and skills, prompt engineering, and where Java's richness for AI solutions stems from. In this "Input/Output" episode of the Inside Java Podcast, recorded during JavaOne 2026, Lize Raes talks to Dan Vega, Spring Developer Advocate at Broadcom, Java Champion, speaker, and author. "Input/Output" is our new show, where we talk to people outside of OpenJDK to bring you their perspectives and insights into what's happening in the Java ecosystem.

JDK 27 entered Ramp-Down-Phase 1 in early June, so we can go over its features. Valhalla's first JDK Enhancement Proposal (401) will likely be part of JDK 28. Show off your Java ideas in the "Modern Java in the Wild" hackathon. There are two interesting articles for those who want to dive deeper into AOT with agents or into using GPU tensor cores from Java. Links: JDK 27 JEP list: https://openjdk.org/projects/jdk/27/ Valhalla mail: https://mail.openjdk.org/archives/list/jdk-dev@openjdk.org/threadAIA3O3LHFZ6T7TIPH7KZT4WS4B6U72U5/ JEP 401 PR: https://github.com/openjdk/jdk/pull/31120 "Java in the Wild" hackathon: https://www.hackster.io/contests/modern-java-in-the-wild AOT vs agents: https://bugs.openjdk.org/browse/JDK-8387190 AOT and JVMTI agents: https://bugs.openjdk.org/browse/JDK-8387194 "Exploiting GPU Tensor Cores": https://openjdk.org/projects/babylon/articles/hat-tensors/hat-tensors  

OpenJDK recently resurrected Project Detroit, an effort to ease Java's interoperability with Python and JavaScript. Interestingly, while both integrations will work through the _java.scripting_ API, there are still differences between them. On top of that, the JavaScript integration needs to explain how it related to the removal of Nashorn in JDK 16. In this "Ask the Architect" episode of the Inside Java Podcast, recorded during JavaOne 2026, Nicolai Parlog talks to Mikael Vidsted, lead of the Java Virtual Machine team at Oracle, about Project Detroit. Project Detroit: https://openjdk.org/projects/detroit/

JDK Enhancement Proposals are OpenJDK's vehicle for documenting and communicating substantial changes of the Java language, its APIs, and the runtime but also the JDK project itself, for example when it comes to development processes. Their well-defined structure and the immense care that goes into writing them make them eminently readable and understanding them well is essential to understanding Java's development. In this "Ask the Architect" episode of the Inside Java Podcast, recorded during JavaOne 2026, Nicolai Parlog talks to Alex Buckley, the Guardian of the JEP process.

Java's use of memory, often chided for being excessive, is actually a strength as it trades more memory use for fewer CPU cycles. Java can only make this tradeoff due to its moving garbage collectors, something more memory efficient platforms often cannot. But what's the point in leaving available memory on the table if using it makes your program run faster? Efficient use of that resource wouldn't be to leave it untapped but to use it to speed up the program. In this "Ask the Architect" episode of the Inside Java Podcast, recorded during JavaOne 2026, Nicolai Parlog talks to Ron Pressler, Java Architect at Oracle.

With JDK 27 introducing hybrid key exchange schemes that combine ML-KEM with traditional ECDHE algorithms, Java applications can gain TLS-layer protection against the harvest-now, decrypt-later threat without rewriting business logic. In this episode of the Inside Java Newscast, Ana explains post-quantum hybrid key exchange for TLS 1.3 and demonstrates how a Java application can take advantage of it. See https://inside.java/podcast  

Flexible constructor bodies were added to Java 25 with JEP 513. In this episode of the Inside Java Newscast Billy Korando will review the issues with how constructors used to work before Java 25, either forcing developers to write convoluted code, or in some cases undermining the safety and integrity of child classes. Billy will then cover how flexible constructor bodies address these issues and how Java developers can use them to write safer code and better designed applications. Make sure to check https://inside.java/podcast