jackson - do not serialize lazy objects

Question

I have an entity:

@Entity
public class Book {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private long id;

    @Column
    private Stri         


        

Answer 1

You can use Jackson's JSON Filter Feature:

@Entity
@JsonFilter("Book") 
public class Book {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private long id;

    @Column
    private String title;

    @OneToMany(fetch = FetchType.LAZY, mappedBy = ("movie"),cascade = CascadeType.ALL)
    private List genre;
} 

@Entity
@JsonFilter("Genre")
public class Genre {
   ...
}

Then in the Controller you specify what to filter:

@Controller
public class BookController {
      @Autowired
      private ObjectMapper objectMapper;

      @Autowird
      private BookRepository bookRepository;

       @RequestMapping(value = "/book", method = RequestMethod.GET, produces =  "application/json")
       @ResponseBody
       public ResponseEntity getBooks() {

          final List books = booksRepository.findAll();
          final SimpleFilterProvider filter = new SimpleFilterProvider();
          filter.addFilter("Book", SimpleFilterProvider.serializeAllExcept("Genre");
          return new ResponseEntity<>(objectMapper.writer(filter).writeValueAsString(books), HttpStatus.OK)
       }

}

In this way, you can control when you want to filter the lazy relation at runtime