What’s New in Spring Boot 3.2? Java 21 Virtual Threads, SSL Hot‑Reload & AI Preview

VMware announced the upcoming release of Spring Boot 3.2, the first version to support Java 21 virtual threads (Project Loom), offering significant performance and efficiency gains.

According to evangelist Josh Long, each traditional thread consumes about 2 MB of memory, whereas virtual threads are lightweight.

Spring Boot 3.2 also adds support for GraalVM native image compilation using virtual threads and improves startup time.

A new SSL hot‑reload feature allows embedded web servers such as Tomcat and Netty to update certificates in real time without restarting, preserving existing connections on the old certificate and switching new connections to the updated one.

VMware reports continuous growth in Spring Boot usage, with a five‑year‑long 50 % year‑over‑year increase according to its annual Spring State report.

The Spring framework originated from Rod Johnson’s 2002 book criticizing the complexity of J2EE, leading to the creation of Spring and later Spring Boot, first released in 2014 to simplify application development.

Today Spring Boot is the default choice for many Java projects, and the ecosystem is expanding into the AI era with Spring AI, currently in preview, which abstracts services like OpenAI and Azure OpenAI.

To add the AI starter to an existing project, run: spring boot add ai This command adds the AI extension library, enabling chatbot and other AI capabilities.

Edited by 万能的大雄. Reference: https://docs.spring.io/spring-ai/reference/index.html