Upgrade Spring Boot from 2.7.x to 3.5.7 and Spring Cloud to 2025.0.0

[devin-ai-integration]

Upgrade Spring Boot from 2.7.x to 3.5.7 and Spring Cloud to 2025.0.0

Summary

This PR upgrades all 7 microservices from Spring Boot 2.7.14/2.7.15 to 3.5.7 (latest) and Spring Cloud from 2021.0.8 to 2025.0.0 (Northfields release train). This is a major version upgrade requiring breaking change fixes for Spring Boot 3.x and Spring Cloud 2022.0.0+ compatibility.

Services upgraded:

• API-Gateway: 2.7.14 → 3.5.7
• Service-Registry: 2.7.14 → 3.5.7
• User-Service: 2.7.14 → 3.5.7
• Account-Service: 2.7.15 → 3.5.7
• Fund-Transfer: 2.7.14 → 3.5.7
• Transaction-Service: 2.7.15 → 3.5.7
• Sequence-Generator: 2.7.15 → 3.5.7

Key changes made:

1. Updated all 7 pom.xml files with new Spring Boot and Spring Cloud versions
2. Migrated javax.* → jakarta.* imports in 7 files (Jakarta EE 10 requirement for Spring Boot 3.x):
   • Entity classes: Account.java, FundTransfer.java, Transaction.java, User.java, UserProfile.java, Sequence.java
   • Service class: UserServiceImpl.java (javax.transaction.Transactional → jakarta.transaction.Transactional)
3. Updated Spring Security configuration (API-Gateway/SecurityConfig.java) to use Spring Security 6.0 lambda DSL:
   • Replaced deprecated .authorizeExchange(), .csrf().disable(), .oauth2Login(), .oauth2ResourceServer().jwt() with lambda-based syntax
   • Added Customizer.withDefaults() for default OAuth2 configuration
4. Removed @EnableEurekaClient annotation from 3 services (API-Gateway, User-Service, Transaction-Service) - no longer needed in Spring Cloud 2022.0.0+ as Eureka client is now auto-configured
5. Removed javax.ws.rs exclusion from User-Service pom.xml - no longer needed in Spring Boot 3.x

Review & Testing Checklist for Human

⚠️ IMPORTANT: Only API-Gateway has been verified to compile locally. The other 6 services need verification.

• Compile all 7 services - Run mvn clean compile for each service to ensure no compilation errors
• Run unit tests - Execute mvn test for Service-Registry, Sequence-Generator, and API-Gateway (the services with test suites)
• Test Eureka service discovery - Verify that API-Gateway, User-Service, and Transaction-Service still register with Service-Registry correctly despite @EnableEurekaClient removal
• Test API Gateway OAuth2 authentication - Verify /api/users/register is publicly accessible and other endpoints require authentication. Test OAuth2 login flow and JWT resource server functionality
• Test database operations - For User-Service, Account-Service, Fund-Transfer, and Transaction-Service, verify JPA entity operations work correctly with jakarta.persistence.* imports

Recommended test plan:

1. Start Service-Registry first
2. Start Sequence-Generator and verify it registers with Eureka
3. Start API-Gateway and verify OAuth2 configuration works
4. If you have MySQL/Keycloak configured, test User-Service, Account-Service, Fund-Transfer, and Transaction-Service end-to-end

Notes

• All changes follow the official Spring Boot 3.0 Migration Guide
• Java 17 is already configured (required minimum for Spring Boot 3.x)
• Keycloak Admin Client 21.0.1 is compatible with Spring Boot 3.x and Jakarta EE
• No CI is configured for this repository, so manual testing is critical

Link to Devin run: https://app.devin.ai/sessions/ca17b79a5eb24855a35b4d9dafd6cbc1
Requested by: Sam Fertig (@samfert-codeium)

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