Upgrade to Spring Boot 3.5.6 and Spring Cloud 2025.0.0

[devin-ai-integration]

Upgrade to Spring Boot 3.5.6 and Spring Cloud 2025.0.0

Summary

This PR upgrades all 7 microservices from Spring Boot 2.7.x to Spring Boot 3.5.6 (latest stable) and Spring Cloud from 2021.0.8 to 2025.0.0 (Northfields release). This is a major framework upgrade requiring namespace migration, dependency updates, and code changes for API compatibility.

Changes Applied

Version Upgrades (all 7 services):

• Spring Boot: 2.7.14/2.7.15 → 3.5.6
• Spring Cloud: 2021.0.8 → 2025.0.0
• Keycloak Admin Client (User-Service): 21.0.1 → 26.0.7

Namespace Migration (javax → jakarta):

• Migrated all JPA entity classes from javax.persistence to jakarta.persistence (6 files)
• Migrated transaction annotation from javax.transaction to jakarta.transaction (1 file)

Code Changes for Spring Boot 3.x Compatibility:

• Removed deprecated @EnableEurekaClient annotations (API-Gateway, User-Service, Transaction-Service) - Spring Boot 3.x auto-registers with Eureka
• Updated GlobalExceptionHandler method signatures (Account-Service, User-Service) - changed HttpStatus parameter to HttpStatusCode per Spring Framework 6.x API changes
• Added explicit commons-io dependency (Account-Service, Fund-Transfer, Transaction-Service) - no longer included transitively in Spring Boot 3.x

Verification Completed

✅ All 7 services compile successfully
✅ Tests pass for Service-Registry, Sequence-Generator, and API-Gateway
✅ No remaining javax.persistence imports in codebase

Review & Testing Checklist for Human

⚠️ This is a HIGH-RISK PR due to major version upgrades and limited testing coverage. Thorough end-to-end testing is required before merging.

• Deploy all services in complete environment - Set up MySQL, Keycloak, and all 7 services in a test environment. Verify all services start successfully and register with Eureka.

• Test User-Service Keycloak integration - The Keycloak Admin Client was upgraded 5 major versions (21.0.1 → 26.0.7). Verify user creation, updates, and authentication flows still work correctly.

• Test Account-Service, Fund-Transfer, and Transaction-Service - These services could not be tested locally due to MySQL/Keycloak dependencies. Verify all CRUD operations, Feign client calls, and error handling work correctly.

• Test API-Gateway OAuth2 flows - Verify authentication, authorization, and routing work correctly. Note: Test output shows deprecation warnings for Gateway configuration properties (spring.cloud.gateway.routes → spring.cloud.gateway.server.webflux.routes), but functionality should still work.

• Test inter-service communication - Verify services can discover and communicate with each other through the API Gateway and via direct Feign client calls.

Recommended Test Plan

1. Start all services: Service-Registry → Sequence-Generator → API-Gateway → User/Account/Fund-Transfer/Transaction services
2. Create test user via User-Service
3. Create test account via Account-Service
4. Perform fund transfer via Fund-Transfer service
5. Verify transactions are recorded in Transaction-Service
6. Test all API Gateway routes and OAuth2 protected endpoints
7. Check Eureka dashboard to verify all services are registered

Notes

• Known deprecation: API-Gateway configuration properties have been renamed in Spring Cloud 2025.0.0. Current properties still work but will need updating in the future. See test output for details.
• Missing dependencies: I had to explicitly add commons-io to 3 services because it's no longer a transitive dependency in Spring Boot 3.x. Monitor for other missing transitive dependencies during testing.
• Testing limitation: 4 out of 7 services could not be fully tested locally due to missing MySQL and Keycloak infrastructure. Compilation and basic Spring context loading were verified via unit tests only.

---

Link to Devin run: https://app.devin.ai/sessions/a3d47422eceb40258738c6131c1e4004
Requested by: Sam Fertig (@samfert-codeium)

[devin-ai-integration]

🤖 Devin AI Engineer

I'll be helping with this pull request! Here's what you should know:

✅ I will automatically:

• Address comments on this PR. Add '(aside)' to your comment to have me ignore it.
• Look at CI failures and help fix them

Note: I can only respond to comments from users who have write access to this repository.

⚙️ Control Options:

• Disable automatic comment and CI monitoring