Jackson Annotations - @JsonManagedReference
@JsonManagedReferences e JsonBackReferences são usados para exibir objetos com relacionamento pai-filho. @JsonManagedReferences é usado para se referir ao objeto pai e @JsonBackReferences é usado para marcar objetos filho.
Exemplo - @JsonManagedReferences
import java.io.IOException;
import java.text.ParseException;
import java.util.ArrayList;
import java.util.List;
import com.fasterxml.jackson.annotation.JsonBackReference;
import com.fasterxml.jackson.annotation.JsonManagedReference;
import com.fasterxml.jackson.databind.ObjectMapper;
public class JacksonTester {
public static void main(String args[]) throws IOException, ParseException {
ObjectMapper mapper = new ObjectMapper();
Student student = new Student(1, "Mark");
Book book1 = new Book(1,"Learn HTML", student);
Book book2 = new Book(1,"Learn JAVA", student);
student.addBook(book1);
student.addBook(book2);
String jsonString = mapper
.writerWithDefaultPrettyPrinter()
.writeValueAsString(book1);
System.out.println(jsonString);
}
}
class Student {
public int rollNo;
public String name;
@JsonBackReference
public List<Book> books;
Student(int rollNo, String name){
this.rollNo = rollNo;
this.name = name;
this.books = new ArrayList<Book>();
}
public void addBook(Book book){
books.add(book);
}
}
class Book {
public int id;
public String name;
Book(int id, String name, Student owner){
this.id = id;
this.name = name;
this.owner = owner;
}
@JsonManagedReference
public Student owner;
}
Resultado
{
"id" : 1,
"name" : "Learn HTML",
"owner" : {
"rollNo" : 1,
"name" : "Mark"
}
}