Spring Boot 3.4.0 RC1 Release Notes

Spring Boot 3.4.0-RC1 Release Notes

For changes in earlier milestones, please refer to:

Upgrading from Spring Boot 3.3

Bean-based conditions

The behavior of @ConditionalOnBean and @ConditionalOnMissingBean has changed when used on a @Bean method and the annotation attribute is set. As before, both conditions will use the return type of the @Bean method as a default for the type to match. Previously, this default was not used if name, type, or value had been set. As of Spring Boot 3.4, this default will also not be used if annotation has been set. To restore the previous behavior, specify both a value that is the return type of the @Bean method and annotation.

Minimum Requirements Changes

Gradle

The minimum supported version of Gradle 8.x is now 8.4. Support for Gradle 7 (7.6.4 and later) remains.

New and Noteworthy

Tip	Check the configuration changelog for a complete overview of the changes in configuration.

Connection details

HazelcastConnectionDetails has been added, with implementations for Docker Compose and Testcontainers.

Virtual threads

OtlpMeterRegistry is now using virtual threads, if enabled.

The Undertow web server now uses virtual threads, if enabled.

Dependency Upgrades

Spring Boot 3.4.0-RC1 moves to new versions of several Spring projects:

TBD

Numerous third-party dependencies have also been updated, some of the more noteworthy of which are the following:

TBD

Miscellaneous

Apart from the changes listed above, there have also been lots of minor tweaks and improvements including:

The partitioned attribute of session cookies can now be set through properties.
A new server.jetty.max-form-keys property has been added to customize Jetty’s max form keys.