👀 Views: 0 💬 Answers: 1 📅 Created: 2025-06-06

spring jpa hibernate Java

I've been researching this but I'm reviewing some code and Hey everyone, I'm running into an issue that's driving me crazy. I'm facing a `LazyInitializationException` when trying to access a collection of related entities after my transaction has ended. I'm using Spring Data JPA 2.5.2 with Hibernate 5.4.32. Here's a simplified version of my entity classes: ```java @Entity public class User { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long id; @OneToMany(mappedBy = "user", fetch = FetchType.LAZY) private List<Order> orders; // Getters and Setters } @Entity public class Order { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long id; @ManyToOne @JoinColumn(name = "user_id") private User user; // Getters and Setters } ``` In my service layer, I'm fetching a user and then trying to access the orders collection: ```java @Service public class UserService { @Autowired private UserRepository userRepository; @Transactional(readOnly = true) public User getUserWithOrders(Long userId) { User user = userRepository.findById(userId).orElseThrow(() -> new EntityNotFoundException("User not found")); return user; // Orders not initialized here } } ``` After calling `getUserWithOrders`, I'm trying to access `user.getOrders()` in my controller: ```java @GetMapping("/user/{id}") public ResponseEntity<User> getUser(@PathVariable Long id) { User user = userService.getUserWithOrders(id); // This line throws LazyInitializationException List<Order> orders = user.getOrders(); return ResponseEntity.ok(user); } ``` The `LazyInitializationException` occurs because the Hibernate session is closed after the transaction ends, leaving the orders uninitialized. I've tried several approaches like changing the fetch type to `EAGER`, but that causes performance issues by loading too much data. Is there a recommended way to handle this without loading unnecessary data or causing this exception? Should I consider using `JOIN FETCH` in my query instead? What is the best practice here? I'd really appreciate any guidance on this. The stack includes Java and several other technologies. I appreciate any insights!