What’s New in Spring Boot 2.4.0? Top 12 Features You Must Know

On November 12, 2020, Spring announced the Spring Boot 2.4.0 GA release, bringing a host of new features and improvements.

Key Updates

1. Version naming change: the "RELEASE" suffix is removed, so the version is now simply 2.4.0.

2. Improved handling of application.properties and application.yml. Simple configurations upgrade seamlessly, while complex setups may require adjustments; see the migration guide for details.

3. New spring.config.import property enables importing common Kubernetes configuration trees.

4. A new startup endpoint displays detailed application start‑up information, helping identify beans that delay startup.

5. Docker/Buildpack support is enhanced, making image building more convenient.

6. Full support for Java 15.

7. Dependency upgrades, including:

Spring AMQP 2.3

Spring Batch 4.3

Spring Data 2020.0

Spring Framework 5.3

Spring HATEOAS 1.2

Spring Integration 5.4

Spring Kafka 2.6

Spring Retry 1.3

Spring Security 5.4

Spring Session 2020.0

8. Embedded‑database detection logic is refined: a database is considered embedded only when it runs in memory, so file‑based H2, HSQL, or Derby instances will not be auto‑initialized.

9. Logback configuration property names have changed: logging.pattern.rolling-file-name →

logging.logback.rollingpolicy.file-name-pattern

logging.file.clean-history-on-start

→

logging.logback.rollingpolicy.clean-history-on-start

logging.file.max-size

→

logging.logback.rollingpolicy.max-file-size

logging.file.total-size-cap

→

logging.logback.rollingpolicy.total-size-cap

logging.file.max-history

→ logging.logback.rollingpolicy.max-history 10. By default, HTTP traces no longer include Cookie request headers or Set‑Cookie response headers; to retain them after upgrading from 2.3, set management.trace.http.include to include cookies, errors, request-headers, and response-headers.

11. Undertow now preserves the original request URL when forwarding, aligning with the Servlet specification. The previous default can be restored by setting server.undertow.preserve-path-on-forward=true.

12. Elasticsearch users should note that low‑level RestClient auto‑configuration is removed, while RestHighLevelClient remains auto‑configured; upgrading Flyway users should move to Flyway 6 before upgrading Spring Boot.

Reference

https://spring.io/blog/2020/11/12/spring-boot-2-4-0-available-now