Spring MVC: How to Prevent Lazy Loading of JPA Entities in a JSON Response?
I'm collaborating on a project where I'm collaborating on a project where I'm having a hard time understanding I'm relatively new to this, so bear with me... I'm working with an scenario where my JPA entities are being lazily loaded when I return them in a Spring MVC controller method. This leads to `org.hibernate.LazyInitializationException` errors when the session is closed. I'm using Spring Boot 2.5.4 with Hibernate 5.5.3. Here's a simplified version of my entity and controller: ```java @Entity public class User { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long id; private String username; @OneToMany(mappedBy = "user", fetch = FetchType.LAZY) private List<Post> posts; // Getters and Setters } @Entity public class Post { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long id; private String content; @ManyToOne @JoinColumn(name = "user_id") private User user; // Getters and Setters } ``` In my controller, I have: ```java @RestController @RequestMapping("/api/users") public class UserController { @Autowired private UserRepository userRepository; @GetMapping("/{id}") public User getUser(@PathVariable Long id) { return userRepository.findById(id).orElse(null); } } ``` When I try to access the user endpoint, it throws a `LazyInitializationException` because the posts are not fetched before the session closes. I've tried changing the fetch type to `EAGER`, but that causes performance optimization due to excessive data loading. I've also considered using DTOs to control what gets returned, but I'm unsure about the best practices here. Should I implement a method in my repository to join fetch the posts? What would be the best way to handle the lazy loading while maintaining performance? Any advice would be appreciated! Has anyone else encountered this? For context: I'm using Java on macOS. What am I doing wrong?