What's new in Spring Modulith?

Spring Modulith is a relatively new addition to the Spring ecosystem and guides developers in structuring their applications to create more maintainable software.

This talk briefly introduces the ideas of the project, and casts light on the features of the most recent releases, the new 2.0 major version coming in November in particular. Highlights include the revamped event publication registry, advanced C4 model integration, and significantly overhauled observability and actuator support.

Transcript

1. What's new in Spring Modulith?  Oliver Drotbohm  info@odrotbohm.de  /  /  odrotbohm
3. What's new in Spring Modulith?
4. What is Spring Modulith?
5. “Spring Modulith allows developers to build well-structured Spring Boot applications and guides developers in finding and working with application modules driven by the domain. It supports the verification of such modular arrangements, testing individual modules, integrating them in eventually- consistent way, observing the application’s behavior on the module level, and creating documentation snippets based on the arrangement created. — Spring Modulith project page
6. DEMO
7. Nested Application Modules 1.3
8. Module B Module A Nested Application Modules API
9. Module B Module A Nested A Nested B Nested Application Modules API
10. Module B Module A Nested A Nested B Nested Application Modules API
11. DEMO
12. Named Interfaces
13. My Module Provided Interface Required Interface All public types in the module's base package All dependencies to types in other modules My Module Named Interface A named set of types located anywhere inside the module. API SPI mymodule :" api mymodule :" spi Explicit references
14. DEMO
15. import org.springframework.modulith.NamedInterface; @NamedInterface("api") public interface PaymentService { CreditCardPayment pay(Order order, CreditCardNumber creditCardNumber); Optional<Payment<?>$ getPaymentFor(Order order); Optional<Receipt> takeReceiptFor(Order order); } 1.4 2.0 api api - PaymentService - CreditCardPayment - CreditCardNumber - Order - Payment - PaymentService - Receipt // from spring-modulith-api artifact
16. Change-Aware Test Execution 1.3
17. A B C D E Change detected here. We only need to test A!
18. A B C D E Change detected in C. We need to test C and A!
20. DEMO
21. Change-Aware Test Execution  All tests are executed if… - No changes at all - Non-module files have been changed (e.g., pom.xml)  Individual tests are executed if… - They're directly or transitively affected by a change (by default: uncommitted or unpushed, customizable)  CI Integration - Diff anchor configurable via environment variable
22. Event Publication Registry
23. @Service @RequiredArgsConstructor class Checkout { private final OrderRepository orders; private final ApplicationEventPublisher events; @Transactional void complete(Order order) { orders.save(order.complete()); events.publishEvent( OrderCompleted.of(order.getId())); } } @Service class Inventory { @ApplicationModuleListener void on(OrderCompleted event) { /& Update inventory } }
24. Event Publication Published / Processing Completed  Listener  Event How do we distinguish processing from failed events? How do we handle resubmissions in multi-instance setups? Application Listener Decoration !
25. Completed Published Resubmitted Processing Failed 2.0
26. Completed Published Resubmitted Processing Failed 2.0 Application Code Application Listener Decoration !
27. Completed Published Resubmitted Processing Failed 2.0 Application Code Application Listener Decoration !  Additional properties - Number of completion attempts - Last resubmission date
28. DEMO
29. DEMO  Event  Listener  Listener OrderCompleted "
30. Completed Published Resubmitted Processing Failed 2.0
31. Completed Published Resubmitted Processing Failed 2.0
32. Completed Published Resubmitted Processing Failed Staleness Monitor 2.0
33. #
34.  Runtime Support - Extended module metadata in application-modules.json - Improved bootstrap procedure - Structural verification on startup - Revamped observability support, incl. automatic metrics for cross-module event counters  Event Publication Registry - Extended lifecycle - Staleness monitor API  Tool integration - IDEA, VSCode. Eclipse coming.  Application Module Model - Nested Application Modules - Propagating named interface declarations  Verification - VerificationOptions to customize verifications and plug additional ArchUnit rules  Testing - Change-aware test execution - Support for beans contained in test sources  Documentation - Visibility improvements in module canvas - Creates application-modules.json 1.3 2.0 1.4 Summary 2.0 2.0 2.0 2.0 1.3 2.0 1.4 1.4 1.4 1.4
35. Outlook  C4 model integration  Module-aware database migrations  Failure signals from module listeners  Violation freeze
36. Thank you! Oliver Drotbohm ✉ info@odrotbohm.de    odrotbohm