Hibernate @OneToMany Relationship Causes Infinite Loop Or Empty Entries in JSON Result

Question

I have two entities, an entity \"movie\" and an entity \"Clip\" each clip belongs to one movie and a movie can have multiple clips.

My code looks like:

Answer 1

Easy way as Dino Tw said:

Remove the getMovie() function from the Clip class.

That will help you to retrieve the Clip list for each Movie which is associated by movie_id in the Clip entity/table.

Answer 2

Basically JsonIgnore or JsonBackrefrencing will remove linking from one end.

To make proper linking as well as correct Json output, please follow below code snippet :-

@Entity  
@Table(name="Movie")
public class Movie{

@JsonIdentityInfo(generator=ObjectIdGenerators.UUIDGenerator.class, property="@id")
@OneToMany(mappedBy="movie",cascade=CascadeType.ALL,fetch=FetchType.EAGER)
private Set<Clip> clips = new HashSet<Clip>();

}


@Entity  
@Table(name="Clip")
public class Clip{ 

@JsonIdentityInfo(generator=ObjectIdGenerators.UUIDGenerator.class, property="@id")  
@ManyToOne
@JoinColumn(name="movie_id")
@JsonIgnore
private Movie movie;
}

refer below link for further details :- https://www.toptal.com/javascript/bidirectional-relationship-in-json

import com.fasterxml.jackson.annotation.ObjectIdGenerators;

Answer 3

Instead of returning an Entity object, I suggest return a DTO object only with the data you need. You can get one directly from a Hibernate query/criteria results, using result transformers.