Java 25 LTS Arrives: Spring Boot Migration Pain vs. Solon's Ease

Java 25 LTS is now the recommended baseline, with Oracle's NFTC license for Java 21 expiring in September 2026. Spring Boot 3.x to 4.x migration is high-cost due to namespace and API changes, while Solon 4.x claims low migration effort. Solon's architecture, with zero Servlet dependency and a 0.3MB core, enables running the same code on Java 8 through 26.