👀 Views: 82 💬 Answers: 1 📅 Created: 2025-06-12

java spring-boot jpa hibernate Java

I'm building a feature where I'm working on a personal project and I'm currently working on a Spring Boot application with JPA, and I've come across a frustrating scenario with lazy loading of my entities... I've set up an `Order` entity that has a one-to-many relationship with an `Item` entity. I expected to fetch the `Order` and its associated `Items` lazily, but I'm running into a `LazyInitializationException` when trying to access the `Items` outside of the transaction context. Here's a simplified version of my `Order` and `Item` entity classes: ```java @Entity public class Order { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long id; @OneToMany(mappedBy = "order", fetch = FetchType.LAZY) private List<Item> items; // getters and setters } @Entity public class Item { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long id; @ManyToOne @JoinColumn(name = "order_id") private Order order; // getters and setters } ``` In my service layer, I'm fetching the `Order` like this: ```java @Transactional(readOnly = true) public Order getOrder(Long orderId) { return orderRepository.findById(orderId).orElseThrow(() -> new EntityNotFoundException("Order not found")); } ``` Then, when I try to access the `items` in my controller after fetching the `Order`, I get the following behavior: ``` org.hibernate.LazyInitializationException: could not initialize proxy - no Session ``` I've tried adding `@Transactional` to my controller method, but that doesn't seem to help. I've also considered changing the fetch type to `EAGER`, but I’m worried about the performance implications with many `Items` associated with each `Order`. I've also confirmed that my `EntityManager` is being properly managed by Spring. My question is, what are the best practices for handling lazy loading in this scenario? Is there a way to avoid the `LazyInitializationException` without resorting to `EAGER` fetching? Any advice would be appreciated! I'm working in a Windows 11 environment. I'm on macOS using the latest version of Java.