This article explains how to use the new Java features provided within Project Leyden to speed up Spring Boot application startup.

Piotr Minkowski TechBlog

Project Leyden is an experimental OpenJDK initiative that uses Ahead-of-Time (AOT) compilation caching to speed up Java application startup. Using the early access build (EA2, based on JDK 26), you can generate an AOT cache with the -XX:AOTCacheOutput flag on first run, then reuse it with -XX:AOTCache on subsequent runs. Tests with two Spring Boot apps (one using H2+Liquibase, another using Redis) show roughly 40% faster startup times. While promising, the gains are comparable to CRaC and still fall short of GraalVM native image. The key advantage is that Leyden is intended to eventually ship as part of the standard OpenJDK distribution.

Speed up Java Startup with Spring Boot and Project Leyden

<p>Looks interesting.  I guess for bundling the application in a docker container you’d want some extra build steps to generate the AoT cache and then include it as part of the image.</p>
<p>I may see this before retirement when my employer moves to Java 26… We’re on 17 (mostly) with some holdouts still on java 8.</p>
