Spring Boot & AI Bootcamp | Day 4 | Service Layer, REST Controller, Exception Handling & JPA

In Day 4 of our Spring Boot & AI Bootcamp, we continue building the Ticket Service and complete the core service and controller layers of the application. This session focuses on implementing CRUD operations, pagination, REST APIs, exception handling, and testing the Ticket Service using Postman. Topics Covered: 1. Ticket Service Implementation ✅ Retrieving tickets by ID ✅ Listing tickets using pagination with Pageable ✅ Updating ticket status ✅ Deleting tickets ✅ Using @Transactional for read-only operations ✅ Mapping JPA entities to DTOs using method references 2. Controller Layer Development ✅ Building the TicketController ✅ Using @RestController for REST APIs ✅ Creating endpoints for ticket operations ✅ Mapping HTTP methods such as POST, GET, PATCH and DELETE ✅ Connecting controller endpoints with the service layer 3. Pagination ✅ Using Spring Data's Pageable ✅ Retrieving data in manageable chunks ✅ Avoiding the need to load the entire database ✅ Improving API performance and user experience 4. Testing with Postman ✅ Testing the Ticket CRUD APIs ✅ Creating, retrieving, updating and deleting tickets ✅ Verifying API responses and application behaviour 5. Default Values and Entity Design ✅ Discussing where default values should be handled ✅ Using @PrePersist for entity-level defaults ✅ Understanding when application-level defaults are more appropriate 6. Global Exception Handling ✅ Introduction to @RestControllerAdvice ✅ Creating consistent JSON error responses ✅ Handling application exceptions centrally ✅ Creating a custom ResourceNotFoundException ✅ Understanding RuntimeException and the use of super() in custom exception constructors The session also sets up the next stage of the project, where we will integrate AI services using Groq through a separate microservice and continue building the complete AI-powered ticket processing system. This Spring Boot & AI Bootcamp focuses on building production-oriented backend systems using Spring Boot, Microservices, PostgreSQL and AI integration. Subscribe to ‪@CodeKerdos‬ for upcoming sessions on Spring Boot, Java, Microservices, System Design, Backend Development and AI. #SpringBoot #Java #Microservices #SpringDataJPA #JPA #RESTAPI #PostgreSQL #ExceptionHandling #BackendDevelopment #AI #Groq #SystemDesign #CodeKerdos