What’s New in Spring Boot 2.5.5? Key Fixes, Docs Updates, and Dependency Upgrades

On September 23, the official Spring Boot 2.5.5 release was announced, bringing 41 bug fixes, documentation improvements, and dependency upgrades.

<parent>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-parent</artifactId>
  <version>2.5.5</version>
  <relativePath/> <!-- lookup parent from repository -->
</parent>

Bug Fixes

Fix endpoint not cleaning SPRING_APPLICATION_JSON by default #28081

Fix startup failure when initializing DataSource for Flyway and Spring Integration under non‑null mode #28079

Correct Web MVC metrics status when a filter throws an exception other than NestedServletException #28069

Handle special characters in URL causing Undertow to throw MalformedURLException #28032

Resolve errors when deleting builder images after concurrent image builds #27993

Prevent memory leak in standalone Tomcat War deployment

Fix IndexOutOfBoundsException when running Zip64 jar larger than 4 GB #27900

Correct Azure App Service detection on Windows #27819

Resolve errors with @MockBean combined with @Repeat #27798

Fix NullPointerException in RoutingDataSourceHealthContributor when target is null #27698

Documentation Adjustments

devtools restart not working when using AspectJ weaving #28083

Document default value for spring.data.elasticsearch.client.reactive.endpoints #28072

Selenium auto‑configuration now requires HtmlUnit #27943

Document Java compiler -parameters flag in spring-boot-starter-parent #27885

Fix inconsistent developer tools documentation #27876

Correct typos in Javadoc #27873

Record how to parameterize WebTestClient output directory for REST Docs #27803

Add Java 17 documentation support #26767

Dependency Upgrades

Ehcache3 to 3.9.6

Glassfish EL to 3.0.4

Groovy to 3.0.9

Gson to 2.8.8

Jackson Bom to 2.12.5

Jetty EL to 9.0.52

jOOQ to 3.14.15

Kotlin to 1.5.31

Kotlin Coroutines to 1.5.2

Lettuce to 6.1.5.RELEASE

Logback to 1.2.6

Maven War Plugin to 3.3.2

Micrometer to 1.7.4

Netty to 4.1.68.Final

Netty tcNative to 2.0.43.Final

Reactor to 2020.0.11

SendGrid to 4.7.5

Spring Data to 2021.0.5

Spring Framework to 5.3.10

Spring HATEOAS to 1.3.4

Spring Integration to 5.5.4

Spring Kafka to 2.7.7

Tomcat to 9.0.53

Although 2.5.5 is a maintenance release, it’s noteworthy that after this update the Spring Initializr now offers Java 17 as a selectable version.

From Java 8 to Java 17, the open‑source ecosystem is moving forward—are you ready?