A curated weekly roundup for Java developers covers a Hibernate second-level cache optimization achieving a 3.2x speedup using @Immutable and @Cache(READ_ONLY) annotations, JEP 540 (a new incubating JSON API) targeting JDK 28, plus links on Gradle/Renovate integration, AI agents in enterprise delivery, and release notes for Quarkus, Micronaut, LangChain4j, Helidon, and other JVM ecosystem tools.
Questions this post answers
How much faster is Hibernate's second-level cache when using @Immutable and @Cache(READ_ONLY) together?
Combining @Immutable, @Cache(READ_ONLY), and field-level @Mutability(Immutability.class) produced a 3.2x speedup, cutting execution time from 286 seconds to 90 seconds in a case study. The same case study found that omitting the JSONB field annotation caused an 8.1x slowdown, showing how much annotation choices affect cache performance. Developers tuning Hibernate cache performance can track findings like this one on daily.dev.
What is JEP 540 and what does it add to Java?
JEP 540 proposes a new, incubating, dependency-free JSON API for straightforward parsing and generation, and it is moving toward inclusion in JDK 28. The API is described as deliberately small, aimed at simple JSON use cases rather than replacing full-featured third-party JSON libraries. Java developers watching upcoming JDK features can follow JEP progress like this on daily.dev.