Could not write JSON: Infinite recursion (StackOverflowError); nested exception spring boot

Question

This is my District Controller, when I try to fetch data after saving I get the error, even when I try get object form getDistrict(Long id) the same strikes ple

Answer 1

I've been struggling with the same problem for days, I tried @JsonIgnore, @JsonManagedReference and @JsonBackReference annotation, and even @JsonIdentityInfo annotation and none of them have worked.

If you (the future readers ) are in the same situation, the solution is easier than you expected, simply put @JsonIgnore or @JsonManagedReference / @JsonBackReference on the attribute's getter and not on the attribute itself. And that will do.

Here's a simple example how to do so :

Say we have two classes, Order and Product, and OneToMany relation between them.

Order class

public class Order{
  @Id
  @GeneratedValue(strategy = GenerationType.AUTO)
  private String id_order;
  private double price;
  @OneToMany(mappedBy = "order")
  @LazyCollection(LazyCollectionOption.FALSE)
  private List products
  //constructor, getters & setter 
}

Product Class:

public class Product{
   @Id
   @GeneratedValue(strategy = GenerationType.AUTO)
   private String id_product;
   private String name;
   @ManyToOne
   @JoinColumn(name = "id_order")
   private Order order;
   //consturctor, getters & setters
 }

So in order to use @JsonManagedReference and @JsonBackReference, just add them to the getters as the following :

public class Order{
  @Id
  @GeneratedValue(strategy = GenerationType.AUTO)
  private String id_order;
  private double price;
  @OneToMany(mappedBy = "order")
  @LazyCollection(LazyCollectionOption.FALSE)
  private List products
  //constructor, getters & setter 
  @JsonManagedReference
  public List getProducts(){
    return products;
}

Product class:

public class Product{
  @Id
  @GeneratedValue(strategy = GenerationType.AUTO)
  private String id_product;
  private String name;
  @ManyToOne
  @JoinColumn(name = "id_order")
  private Order order;
  //consturctor, getters & setters
  @JsonBackReference
  public Order getOrder(){
    return order;
  }
 }