Spring Cloud Contract Moves to Stubborn.sh, JobRunr Hits Initializr

Josh Long's latest This Week in Spring brings a handful of notable updates for the Spring ecosystem. The biggest news: JobRunr, the distributed job execution engine, is now available directly on Spring Initializr. That means you can scaffold a new project with JobRunr baked in from the start, no manual dependency wrangling. For teams building background job pipelines in Spring Boot, this is a welcome quality-of-life improvement.

Spring Cloud Contract Finds a New Home

Spring Cloud Contract, the contract-testing tool that helps microservices teams verify API compatibility, is transitioning to Stubborn.sh. The move suggests a shift toward a more focused, possibly commercial, stewardship. If your team relies on Spring Cloud Contract for consumer-driven contract tests, keep an eye on the migration guide and timeline.

Spring Framework 7 and Boot 4: Null-Pointer Elimination

Moritz Halbritter gave a talk on how Spring Framework 7 and Spring Boot 4 are tackling null-pointer issues at the framework level. The approach likely involves compile-time checks and runtime assertions to surface null problems earlier. This is a practical improvement for anyone tired of debugging NPEs in large Spring applications.

Spring AI Ecosystem Grows

Multiple Spring AI items surfaced: Craig Walls wrote about using more than one LLM with Spring AI, and a Baeldung tutorial covered the new MCP annotations. Spring AI continues to mature as a framework for integrating LLMs into Java applications. If you're building AI features on the JVM, these are worth a look.

Kafka Streams Dead-Letter Queues

A Michelin engineering blog post dives into using Spring for Apache Kafka 4.1 with Kafka Streams' dead-letter queue support. For event-driven architectures, DLQs are critical for handling deserialization errors or processing failures without losing data. The post shows how to wire it up with Spring Kafka's configuration.

Other Highlights

Type-safe property paths in Spring Data (video tutorial)
Confluent's updated Spring Boot getting-started guide
Spring AI self-correcting structured output podcast with Sébastien Deleuze