Hibernate OneToMany java.lang.StackOverflowError

Question

It\'s my first question here on stack, so please be gentle :D

I\'m trying to create hibernate OneToMany relationship. When I try to fetch some data from my DB, I\'m

Answer 1

Also see: Hibernate throws StackOverflowError when querying

In my case, I was using the @IdClass annotation on an entity which had a foreign key as part of its primary key:

@IdClass(MyEntity.MyEntityKey.class)
public class MyEntity {
   public static class MyEntityKey {
       private Foo parent;
       private int count;
       // Getters, setters, constructor, ...
   }

   @Id
   private Foo parent;
   @Id
   private int number;
  
   //...
}

Now when loading Foo and eagerly loading all MyEntitys, Hibernate was again loading the parent entity Foo while building the key which resulted in the stack overflow.

I fixed the issue by modelling the id using explicit key properties (i.e. including the keys of Foo in MyEntityKey rather than just a reference to Foo) as shown in Composite key handling, using @Idclass annotation in Spring boot java (also applied to Non-Spring Hibernate). In short: Use the @JoinColumns annotation to specify the relationship between the navigation property (to parent) and the id columns.