Explainable AI Agents: Capture LLM Tool Call Reasoning with Spring AI

When building AI agents with tool calling capabilities, developers often need insights into why an LLM chose a particular tool—not just which tool it selected. Understanding the model's reasoning process is important for debugging, observability, and building trustworthy AI systems. Spring AI now...

Next level Kotlin support in Spring Boot 4

Following the announcement of the strategic partnership between JetBrains and Spring in May, I would like to share a global update on various Kotlin-related features and documentation enhancements we have made recently, with the goal of making Spring Boot 4 the best framework to develop backend...

Towards Spring Tools 5 - Stereotypes and a new Structural View

When working on Spring projects, developers do not only think in terms of low-level concepts like classes and interfaces. When using Spring, you think about higher-level abstractions and concepts like services, repositories, configuration classes, entities, aggregate roots, and so on. To bring...

This Week in Spring (AI) - May 27th, 2025

Hi, Spring fans! Welcome to another installment of This Week in Spring! This time, I'm talking to you after an insane week behind me. Last week I flew from San Francisco to Stockholm, Sweden where I was the speaker for the JForum event, a monthly meetup. Spring drew the largest audience to JForum...

A Bootiful Podcast: Java Champion and legend Henri Tremblay

Hi, Spring fans! In this installment I talk to Henri Tremblay, head of TS Imagine Canada, Java Champion, Montreal JUG leader, EasyMock lead dev and all around legend!...

A Bootiful Podcast: Daniel Garnier-Moiroux on Passkeys and Spring Security

Hi, Spring fans! In this installment, I talk to my friend and colleague Daniel Garnier-Moiroux about the amazing awesome implications of passkeys in a Spring Security application...

A Bootiful Podcast: cloud native Chris Richardson

Hi, Spring fans! In this installment, Josh Long @starbuxman talks to original cloud native Chris Richardson on microservices, architecture, and more...

This Week in Spring - August 22, 2023

Hi, Spring fans! Welcome to another installment of This Week in Spring! And, would you believe it, I'm writing this at SpringOne 2023, in sunny Las Vegas, Nevada. This is the first in-person SpringOne since 2019, and I'm so, so, so glad to be here! We've got a ton of things to get into this week,...

A Bootiful Podcast: UL Systems founder and chairman Shigeru Urushibara interviews.. me?

Hi, Spring fans! I just crossed 13 years on the Spring team! I just got to spend a lovely day in the presence of one of my heroes and friends, UL Systems founder and chairman, Shigeru Urushibara-san @ulsystems, here in Tokyo, Japan, and in this episode, we sort of flip the script. We had a brief...

The new Spring Boot version validation and upgrade support in Spring Tools

New releases of Spring Boot are being released on a quite frequent schedule and updating your projects to newer versions of Spring Boot is something that many teams and organizations around the globe do as part of their daily work. Sometimes those upgrades are simple and easy, for example for new...

This Week in Spring - December 13th, 2022

Hi, Spring fans! Welcome to another installment of This Week in Spring! I truly, absolutely, can not believe that were nearly done with the year already! Have you made your new years resolutions? Submitted your expense reports? Its that time of the year when Im going to start focusing on staying...

Spring Tips: the road to Spring Framework 6: the new Ahead-of-Time Compilation Engine and GraalVM

Hi, Spring fans! Spring Boot 3 is here or will be tomorrow, on the 24th of November, 2022, to be more precise!, bringing a fantastic new Ahead-of-Time AOT compilation engine that supports GraalVM native images. Join me, and well dive deep into the engine and its interactions with the Spring...

A Bootiful Podcast: Microsoft's Asir Selvasingh on Azure Spring Apps, Java at Microsoft, application security, and more

Hi, Spring fans! In this installment, Josh Long @starbuxma talks to his friend, Microsofts Asir Selvasingh @asirselvasingh, about Azure Spring Apps, Java at Microsoft, Spring, application security, and more. Want to learn more? Join us at SpringOne 6-8 December 2022! Want to meet amazing people...

Spring Authorization Server Is Going 1.0

We are excited to announce that weve started preparing for Spring Authorization Server 1.0 with plans to release the GA version in November 2022. It has been just over two years since we initially announced this new project, and we have come a long way since its initial development. The project h...

A Bootiful Podcast: Cloud guru Tiffany Jernigan

Hi, Spring fans! In this installment, Josh Long @starbuxman talk about his first in-person conference since the pandemic descended upon us -the fabulous Devnexus 2022 show - and talks to colleague, teacher, friend, and Kubernetes legend Tiffany Jernigan @tiffanyfayj...

An update on Java 17+ adoption

As a follow-up to my blog post from last years SpringOne, it is time for an update on our Java 17+ baseline efforts! We established the new baseline on our main branches, with a few milestones out already. The feedback has been very positive, not only in terms of framework improvements but also i...

A Bootiful Podcast: Daniel Garnier-Moiroux on his new book 'Testing Spring Boot Applications'

Hi Spring fans! In this installment I'm thrilled to have had the opportunity to sit down and talk to Daniel Garnier-Moiroux and talk about "Testing Spring Boot Applications," from Manning! testing springboot java kotlin springframework...

Servlet Path Not Correctly Included in Path Matching of XML Authorization Rules

If an application uses to define the servlet path for computing a path matcher, then the servlet path is not included and the related authorization rules are not exercised. This can lead to an authorization bypass...

This Week in Spring - March 31st, 2026

Hi, Spring fans! Welcome to another fun edition of This Week in Spring! I'm writing to you from beautiful Amsterdam ahead of the wonderful Voxxed Days Amsterdam event, and I'm really looking forward to it. If you're there, please come say hello! Also, be aware that I'll be speaking at the Paris J...

A Bootiful Podcast: Start Your Year with Java Right with Java Developer Advocate Billy Korando

Hi, Spring and Java fans! In this episode I am beyond delighted to talk Java developer advocate and longtime friend of the show Billy Korando about the latest-and-greatest in the Java ecosystem...

A Bootiful Podcast: Apache Tomcat legend Mark Thomas (Happy new year!)

In this episode, I talk with Mark Thomas, the legendary and highly prolific committer to Apache Tomcat. Happy New Year!...

A Bootiful Podcast: Java community legend Victor Rentea

Hi, Spring fans! In this installment we talk to the legendary Victor Rentea. This episode was recorded live at Devoxx UK 2025...

Spring Security BCryptPasswordEncoder maximum password length breaks timing attack mitigation

The fix applied in CVE-2025-22228 inadvertently broke the timing attack mitigation implemented in DaoAuthenticationProvider...

Null Safety in Spring applications with JSpecify and NullAway

The initial introduction of the null safety support in Spring dates back to 2017 and the release of Spring Framework 5.0. In 2025, we are evolving that story to bring more added value for Spring developers, either in Java or Kotlin. But before having a deeper look to the changes we are working on...

This Week in Spring - February 11th, 2025

Hi, Spring fans! It's almost Valentine's day, and let me just say: I love the Spring community! It's such an exciting and interesting place to be. Thank you everyone for all that you do. I'm busy preparing for ConFoo, in Montreal, Canada, and for Devnexus, in Atlanta, Georgia. If you're around be...

This Week in Spring - October 8th, 2024

Hi, Spring fans! Welcome to another installment of This Week in Spring! I'm in Antwerp, Belgium, for the amazing Devoxx Belgium 2024 event! I am so happy to be back here, one of the best shows in the Java ecosystem! We've got a lot to get into so let's dive right in! From Spring Cloud Data Flow...

AI Meets Spring Petclinic: Implementing an AI Assistant with Spring AI (Part II)

Recap of Part I In the first part of this blog series, we explored the basics of integrating Spring AI with large language models. We walked through building a custom ChatClient, leveraging Function Calling for dynamic interactions, and refining our prompts to suit the Spring Petclinic use case. ...

A Bootiful Podcast: Timefold Solver AI lead Geoffrey De Smet

Hi, Spring fans! In this installment, I talk to Timefold Solver AI lead Geoffrey De Smet about the amazing new integrations for Spring Boot developers...

Price Reduction - Azure Spring Apps does more, costs less!

We believe in providing the most innovative cloud offerings at incredibly competitive prices. As we operate Azure Spring Apps, we continue to build efficiencies and economies of scale. We are passing those efficiencies to you. Many customers have asked us to lower the size of the base unit to mak...

Spring Tips: Kubernetes Native Java (Redux, 2022)

Hi, Spring fans! In this installment, Josh Long @starbuxman looks at some of the amazing opportunities for building Spring Boot applications intended for production in Kubernetes in mid 2022. The code, as usual, is available on the spring-tips Github organization...

Spring Cloud Azure 4.0 is Now Generally Available

NOTE: Hi, Spring fans! This is a guest post from Sean Li, our friend at Microsoft I am pleased to announce that Spring Cloud Azure 4.0 is now generally available. With this major release we aim to bring better security, leaner dependencies, support for production readiness and more. Version 4...

cve-2026-59284 - HIGH - Spring Cloud Commons no allow list for writable env actuator endpoint

cve-2026-59284 - HIGH - Spring Cloud Commons no allow list for writable env actuator endpoint...

cve-2026-47859 - MEDIUM - Unbounded memory allocation in RFC6587SyslogDeserializer (octet-counted framing) — remote DoS

cve-2026-47859 - MEDIUM - Unbounded memory allocation in RFC6587SyslogDeserializer octet-counted framing — remote DoS...

cve-2026-40996 - MEDIUM - Inbound WS-Security allows RSA PKCS#1 v1.5 key transport by default

cve-2026-40996 - MEDIUM - Inbound WS-Security allows RSA PKCS1 v1.5 key transport by default...

cve-2026-41700 - HIGH - Cross-Site WebSocket Hijacking in Spring for GraphQL

cve-2026-41700 - HIGH - Cross-Site WebSocket Hijacking in Spring for GraphQL...

cve-2026-40994 - HIGH - Wss4jSecurityInterceptor disables WS-I BSP validation by default

cve-2026-40994 - HIGH - Wss4jSecurityInterceptor disables WS-I BSP validation by default...

This Week in Spring - June 2nd, 2026

Hi, Spring fans, and welcome to another momentous installment of This Week in Spring! A lot to get into this week, but let's first take some time to address the meta: where are the May releases? If you read our May 11th post, you know they've been delayed. We wanted to speak a bit more about why ...

Spring AI Agentic Patterns (Part 6): AutoMemoryTools — Persistent Agent Memory Across Sessions

File-Based Long-Term Memory for Spring AI Agents Agents are only as useful as what they remember. Spring AI's Chat Memory stores the full conversation and can persist it across restarts, but when the window fills, the oldest messages are evicted. The upcoming Session API will add recursive...

A Bootiful Podcast: Nate Schutta the fundamentals of software engineering

Hi Spring fans, and happy holidays! I'm delighted to be joined again on this episode by my friend and fellow harbinger of doom in the best possible way, Nate Schutta — co-author of the wonderful book Foundations of Software Engineering!...

Introducing Spring AI Agents and Spring AI Bench

I'd like to introduce two new projects that are part of the Spring AI Community GitHub organization: Spring AI Agents, and Spring AI Bench. These two projects focus on using agentic coding tools—tools you likely already have in your enterprise. In 2025 AI coding agents have matured to the point...

This Week in Spring - October 7th, 2025

Hi, Spring fans! How're you doing this fantastic October afternoon? I'm on a train returning from Frankfurt, Germany, where I spoke at the Cloud Foundry Day Frankfurt event about how awesome it is to build an application with Spring Boot and Cloud Foundry. Yesterday I was in Antwerp, Belgium, and...

Spring Authorization Server moving to Spring Security 7.0

Spring Authorization Server has come a long way since 1.0 was officially released in November 2022. Starting as a project separate from Spring Security, has allowed it to iterate quickly on feature development and ultimately grow a rich feature set for building OAuth2 Authorization Servers. It ha...

This Week in Spring - August 26th, 2025

Hi, Spring fans! Welcome to another installment of This Week in Spring! I'm writing this from the floor of SpringOne, live from lovely Las Vegas! As you can imagine, I've got to get back into it, so we'll make this one a quick one. And if you're here, be sure to say "hi"! In last week's A Bootifu...

A Bootiful Podcast: Architecture sage and Spring Modulith lead Oliver Drotbohm

Hi, Spring fans! In this installment I caught up with architecture guru and Spring Modulith founder and lead Oliver Drotbohm and we looked at some of the amazing possibilities in Spring Modulith 2.0, coming after Spring Framework 7.0 and Spring Boot 4.0 drop later this year!...

A Bootiful Podcast: API oracle Arjen Poutsma

Hi, Spring fans! In this edition, I had the pleasure of chatting with the brilliant Arjen Poutsma, our go-to API oracle. If you’re curious about his fantastic insights, thoughts, and consultancy services, be sure to check out poutsma-principles.com...

A Bootiful Podcast: This Week in Spring (AI) - May 20th, 2025

Hi, Spring fans! Welcome to another installment of This Week in Spring! As I write this, I'm in sunny Stockholm, Sweden for the JForum 123 installment. This is, apparently, the first time the meetup is completely full up since before the pandemic, with more than 150 people in attendance! Tak,...

Prompt Engineering Techniques with Spring AI

This blog post demonstrates practical implementations of Prompt Engineering techniques using Spring AI. The examples and patterns in this article are based on the comprehensive Prompt Engineering Guide that covers the theory, principles, and patterns of effective prompt engineering. The blog show...

A Bootiful Podcast: Spring Legend Glenn Renfro on Devnexus 2025, Cold brews, and More

Hi, Spring fans! In today's installment, I talk to Spring legend Glenn Renfro...

A Bootiful Podcast: 'Just Use Postgres!' author Denis Magda

Hi, Spring fans! In this installment we talk to Java and distributed database ninja Denis Magda about his new book, "Just Use Postgres!", which looks at how to wield Postgres for a variety of use cases that an application developer should know...

Spring Tips: Go Further, Faster with Spring Boot 3.3 (UPDATED)

NB: I had an error in the AppCDS demo in the older video. This video supercedes that video, with a re-recorded segment on AppCDS. Make sure you're watching the latest of these two similarly titled videos! Hi, Spring fans! In this installment we look at ways to make your applications go further,...