v4.0.0

⭐ New Features

• Change tomcat and jetty runtime modules to starters #48175
• Rename spring-boot-kotlin-serialization to align with the name of the Kotlinx module that it pulls in #48076

🐞 Bug Fixes

• Error properties are a general web concern and should not be located beneath server.* #48201
• With both Jackson 2 and 3 on the classpath, @JsonTest fails due to duplicate jacksonTesterFactoryBean #48198
• Gradle war task does not exclude starter POMs from lib-provided #48197
• spring.test.webclient.mockrestserviceserver.enabled is not aligned with its module's name #48193
• SslMeterBinder doesn't register metrics for dynamically added bundles if no bundles exist at bind time #48182
• Properties bound in the child management context ignore the parent's environment prefix #48177
• ssl.chain.expiry metrics doesn't update for dynamically registered SSL bundles #48171
• Starter for spring-boot-micrometer-metrics is missing #48161
• Elasticsearch client's sniffer functionality should not be enabled by default #48155
• spring-boot-starter-elasticsearch should depend on elasticsearch-java #48141
• Auto-configuration exclusions are checked using a different class loader to the one that loads auto-configuration classes #48132
• New arm64 macbooks fail to bootBuildImage due to incorrect platform image #48128
• Properties for configuring an isolated JsonMapper or ObjectMapper are incorrectly named #48116
• Buildpack fails with recent Docker installs due to hardcoded version in URL #48103
• Image building may fail when specifying a platform if an image has already been built with a different platform #48099
• Default values of Kotlinx Serialization JSON configuration properties are not documented #48097
• Custom XML converters should override defaults in HttpMessageConverters #48096
• Kotlin serialization is used too aggressively when other JSON libraries are available #48070
• PortInUseException incorrectly thrown on failure to bind port due to Netty IP misconfiguration #48059
• Auto-configured JCacheMetrics cannot be customized #48057
• WebSecurityCustomizer beans are excluded by WebMvcTest #48055
• Deprecated EnvironmentPostProcessor does not resolve arguments #48047
• RetryPolicySettings should refer to maxRetries, not maxAttempts #48023
• Devtools Restarter does not work with a parameterless main method #47996
• Dependency management for Kafka should not manage Scala 2.12 libraries #47991
• spring-boot-mail should depend on jakarta.mail:jakarta.mail-api and org.eclipse.angus:angus-mail instead of org.eclipse.angus:jakarta.mail #47983
• spring-boot-starter-data-mongodb-reactive has dependency on reactor-test #47982
• Support for ReactiveElasticsearchClient is in the wrong module #47848

📔 Documentation

• Removed property spring.test.webclient.register-rest-template is still documented #48199
• Mention support for detecting AWS ECS in "Deploying to the Cloud" #48170
• Revise AWS section of "Deploying to the Cloud" in reference manual #48163
• Fix typo in PortInUseException Javadoc #48134
• Correct section about required setters in "Type-safe Configuration Properties" #48131
• Use since attribute in configuration properties deprecation consistently #48122
• Document EndpointJsonMapper and management.endpoints.jackson.isolated-json-mapper #48115
• Document support for configuring servlet context init parameters using properties #48112
• Some configuration properties are not documented in the appendix #48095
• Clarify how warnings about soon-to-expire SSL certificates are reported #48063
• Document how to use ContextPropagatingTaskDecorator for propagating trace context over thread boundaries #48053
• Document the level of support for the OpenTelemetry APIs #47960
• Document that you need to build with Java 25 for buildpack build-image Graal support #45501

🔨 Dependency Upgrades

• Upgrade to Cassandra Driver 4.19.2 #48184
• Upgrade to DB2 JDBC 12.1.3.0 #48087
• Upgrade to Elasticsearch Client 9.2.1 #48137
• Upgrade to GraphQL Java 25.0 #48034
• Upgrade to Hibernate 7.1.8.Final #48150
• Upgrade to Jackson Bom 3.0.2 #48089
• Upgrade to Jetty 12.1.4 #48120
• Upgrade to Jetty Reactive HTTPClient 4.1.4 #48151
• Upgrade to jOOQ 3.19.28 #48090
• Upgrade to Kafka 4.1.1 #48185
• Upgrade to Logback 1.5.21 #48091
• Upgrade to Micrometer 1.16.0 #47820
• Upgrade to Micrometer Tracing 1.6.0 #47821
• Upgrade to MySQL 9.5.0 #48092
• Upgrade to Native Build Tools Plugin 0.11.3 #48051
• Upgrade to Neo4j Java Driver 6.0.2 #47997
• Upgrade to Prometheus Client 1.4.3 #48093
• Upgrade to Reactor Bom 2025.0.0 #47822
• Upgrade to Spring AMQP 4.0.0 #47823
• Upgrade to Spring Batch 6.0.0 #47834
• Upgrade to Spring Data Bom 2025.1.0 #47824
• Upgrade to Spring Framework 7.0.1 #48168
• Upgrade to Spring GraphQL 2.0.0 #47826
• Upgrade to Spring HATEOAS 3.0.0 #47827
• Upgrade to Spring Integration 7.0.0 #47828
• Upgrade to Spring Kafka 4.0.0 #47829
• Upgrade to Spring LDAP 4.0.0 #47999
• Upgrade to Spring Pulsar 2.0.0 #47830
• Upgrade to Spring RESTDocs 4.0.0 #47831
• Upgrade to Spring Security 7.0.0 #47832
• Upgrade to Spring Session 4.0.0 #48000
• Upgrade to Spring WS 5.0.0 #47833
• Upgrade to Testcontainers 2.0.2 #48152
• Upgrade to Tomcat 11.0.14 #48094

❤️ Contributors

Thank you to all the contributors who worked on this release:

@K-jun98, @TerryTaoYY, @filiphr, @hojooo, @linw-bai, @nosan, @scottfrederick, @stevearmstrong-dev, @stewue, and @vpavic