I'm looking for a way to export some JPA entities to a REST API, but instead of sending the whole entity every time I want to share just some specific fields depending of the entry point. Here's a small example:
Say we have an Author class with few fields:
@Entity
public class Author implements Serializable{
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = SEQUENCE)
private Long id;
@NotNull
@Size(min = 1, message = "{required.field}")
private String name;
@NotNull
@Size(min = 1, message = "{required.field}")
private String country;
private LocalDate birthDate;
// getters and setters
}
And say we have this REST service (just two methods):
@Path("authors")
public class AuthorREST {
@Inject
private AuthorBC bc;
@GET
@Produces("application/json")
public List<Author> find(@QueryParam("q") String query) throws Exception {
List<Author> result;
if (Strings.isEmpty(query)) {
result = bc.findAll();
} else {
result = bc.find(query);
}
return result;
}
@GET
@Path("{id}")
@Produces("application/json")
public Author load(@PathParam("id") Long id) throws Exception {
Author result = bc.load(id);
if (result == null) {
throw new NotFoundException();
}
return result;
}
}
Now, this way, I'll always have the 4 fields when my API is called.
I understand that if I use Jackson I can set an @JsonIgnore to fields I want to ignore, and they will always be ignored.
But what if I want that, in some cases, my whole entity is returned by one service, and in other service (or other method in the same service), only 2 or 3 fields are returned?
Is there a way to do it?
