Upgrade to Spring Boot 3.4.0 and Spring Cloud 2024.0.0

[devin-ai-integration]

Upgrade to Spring Boot 3.4.0 and Spring Cloud 2024.0.0

Summary

This PR upgrades the entire BankingMicroservices application from Spring Boot 2.7.x to Spring Boot 3.4.0, along with all necessary dependency and code changes for compatibility.

Changes across all 7 services:

• Spring Boot: 2.7.14/2.7.15 → 3.4.0
• Spring Cloud: 2021.0.8 → 2024.0.0
• Keycloak admin client (User-Service): 21.0.1 → 26.0.0

Code migrations:

• javax.persistence.* → jakarta.persistence.* (all entity classes)
• javax.transaction.Transactional → jakarta.transaction.Transactional
• Removed deprecated @EnableEurekaClient annotations (auto-configured in Spring Cloud 2022.0+)
• Updated GlobalExceptionHandler.handleMethodArgumentNotValid() signature: HttpStatus → HttpStatusCode

All services compile successfully and existing tests pass.

Local Testing

Service Registry and API Gateway start successfully with Spring Boot 3.4.0. API Gateway registers with Eureka correctly:

Note: Services requiring MySQL (Sequence-Generator, Account-Service, etc.) fail to start without database - this is expected behavior.

Review & Testing Checklist for Human

This is a major version upgrade with significant breaking changes. CI passing is necessary but insufficient for confidence.

• Test Keycloak integration - The Keycloak admin client jumped 5 major versions (21→26). Verify user registration and authentication flows work end-to-end
• Test database operations - The javax→jakarta JPA migration affects all entities. Create/read/update operations should be tested for at least one service (e.g., Account-Service)
• Test API Gateway routing - Verify requests route correctly through the gateway and OAuth2/JWT validation still works
• Test inter-service communication - Verify Feign client calls between services work (e.g., Fund Transfer calling Account Service)

Recommended test plan:

1. Start Service-Registry, then API-Gateway and at least User-Service + Account-Service
2. Register a new user via POST /api/users/register
3. Obtain JWT token from Keycloak
4. Create an account and verify it persists correctly

Notes

• The codebase has no unit tests for business logic, so runtime testing is essential
• Spring Boot 3.x requires Java 17 minimum (already satisfied)

Link to Devin run: https://app.devin.ai/sessions/3ac39a08d1954d67ac964cf2c3388e79
Requested by: Sam Fertig (sam.fertig@cognition.ai) / @samfert-codeium

[devin-ai-integration]

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud