MIssing parent reference in a bidirectional hibernate mapping - spring

Question

I have a spring rest backend with two entities with a bidirectional relationshop (one-to-many, many to one). To overcome nested fetching issues, #JsonManagedReference/#JsonBackReference has been used for a perent/child relationship between entities.
The entites look as this:
#Entity
#Table(name = "Parent")
#JsonInclude(JsonInclude.Include.NON_NULL)
public class Parent implements java.io.Serializable {
private Integer id;
private List<Child> childList;
#Id
#GeneratedValue(strategy = IDENTITY)
#Column(name = "ID", unique = true, nullable = false)
public Integer getId() {
return this.id;
}
public void setId(Integer id) {
this.id = id;
}
#OneToMany(mappedBy = "parent", fetch = FetchType.LAZY)
#JsonManagedReference
public List<Child> getChildList() {
return childList;
}
public void setChildListe(List<Child> childListe) {
this.childList = childList;
}
}
#Entity
#Table(name = "Child")
#JsonInclude(JsonInclude.Include.NON_NULL)
public class Child implements java.io.Serializable {
private Integer id;
private Parent parent;
#Id
#GeneratedValue(strategy = IDENTITY)
#Column(name = "ID", unique = true, nullable = false)
public Integer getId() {
return this.id;
}
public void setId(Integer id) {
this.id = id;
}
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "ParentID")
#JsonBackReference
public Parent getParent() {
return parent;
}
public void setParent(Parent parent) {
this.parent = parent;
}
}
This works fine when fetching the Parent element, the childset is then fetched alongside and displayed as an json-array.
However, there is no reference to parent in the child element due to the usage of jsonbackreferance.
How can solve this issue ? I need parent reference when fetching child

Answer 1

That would lead to an infinite loop when serializing to JSON. That's the whole reason we don't do bi-direction JSON relationships.
What I would do is add an additional column to the child entity if you need the ID alone.
private Integer parentId;
#Column(name = "ParentID", insertable=false, updateable=false)
public Integer getParentId() {
return parentId;
}