List Ticket Service Layer

In this lesson, we're going to implement the list ticket service layer.

Repository Method Implementation

The first step is to add a method to the TicketRepository interface that will retrieve tickets for a specific user.

We'll add a method called findByPurchaserId that takes two parameters:

Page<Ticket> findByPurchaserId(UUID purchaserId, Pageable pageable);

This method will return a page of tickets, which allows for pagination of results.

Spring Data JPA will automatically implement this method based on the method name, as it understands the relationship between a Ticket and its purchaser.

Service Interface Creation

Next, we'll define the contract for our ticket service by creating the TicketService interface:

public interface TicketService {
  Page<Ticket> listTicketsForUser(UUID userId, Pageable pageable);
}

This interface declares a single method that will retrieve a page of tickets for a given user ID.

Service Implementation

Finally, we'll create the implementation of our TicketService interface:

@Service
@RequiredArgsConstructor
public class TicketServiceImpl implements TicketService {

  private final TicketRepository ticketRepository;

  @Override
  public Page<Ticket> listTicketsForUser(UUID userId, Pageable pageable) {
    return ticketRepository.findByPurchaserId(userId, pageable);
  }
}

The implementation is straightforward - it simply delegates to the repository method we created earlier.

Summary

Added the findByPurchaserId method to TicketRepository
Implemented the TicketService with listTicketsForUser method