$ cat spring-projects/week/2026-09-07.log
the week in review · Sep 7 – Sep 13, 2026
Spring Kafka fixes multi-value JSON header loss
By RepoJournal · composed from the cited sources · human-reviewed weekly · methodology
Spring Batch also deprecated its repository setters and JobExecution getters this week, while Spring Boot moved to milestone snapshots across five projects.
GH-4623: Fix multi-value headers with JSON types spring-projects/spring-kafka
JsonKafkaHeaderMapper.toHeaders only routed headers without a spring_json_header_types entry through fromUserHeader, which holds the multi-value collection logic. Any outbound header with JSON type metadata lost its collection semantics. The fix sends JSON-typed headers through the same path.
5.4.0.RELEASE spring-projects/spring-tools
Spring Tools 5.4.0.RELEASE adds validations and quick fixes for converting to @ApplicationModuleListener, @SpringJUnitConfig, @RestController, and specific @Scope annotations, and extends Claude Code / MCP support. Eclipse distro tags now get created separately from publishing.
Modernize the default RequestCache background-request ignore list spring-projects/spring-security
The default RequestCache now ignores more well-known background paths beyond /favicon.*, tightening the post-authentication redirect. Associated work covers apple-touch-icon requests, which WebKit browsers probe automatically at the domain root.
Documentation and Spring Boot 4 updates and fixes spring-projects/spring-session
Spring Session's docs move to Antora, which drops the single-page version and adds a version drop-down, so version references need updating. Deprecated RuntimeHints#serialization usage is replaced with RuntimeHints#reflection.
Favor NVARCHAR to Prevent Implicit Conversion spring-projects/spring-session
PRINCIPAL_NAME and ATTRIBUTE_NAME DDL switches from VARCHAR to NVARCHAR in Spring Session. VARCHAR mismatches the Unicode (NVARCHAR) parameters the MS JDBC driver sends, causing implicit conversion and weaker index performance.
Apply Nullability to ReplyingKafkaOperations (#4621) spring-projects/spring-kafka
ReplyingKafkaOperations and ReplyingKafkaTemplate gain consistent @Nullable annotations on sendAndReceive and its overloads. Set for auto-cherry-pick to 4.1.x and 4.0.x.
Configure the default delegate in DelegatingByTopicSerialization spring-projects/spring-kafka
A fallback delegate configured in DelegatingByTopicSerialization could be dropped: buildDefault() passes a null pattern, so instantiateAndConfigure() never inserts it into the map configure() walks. The default delegate now has its own field and survives reconfiguration.
Upgrade to SLF4J 2.0.19. spring-projects/spring-data-build
Alongside: Spring Data tracked SLF4J 2.0.19, Kotlin 2.4.20, Jackson 3.1.6, H2 2.5.250, and Hibernate 7.4.7.Final, and builds against Project Reactor 2026.0.0-SNAPSHOT, while Spring Boot moved to milestone snapshots across five Spring projects.
$ ls spring-projects/week/ # the briefings behind this review