I have the following (simplified) Hibernate entities:

@Entity
@Table(name = "package")
public abstract class Package {
protected Content content;

    @ManyToOne(cascade = {javax.persistence.CascadeType.ALL})
    @JoinColumn(name = "content_id")
    @Fetch(value = FetchMode.JOIN)
    public Content getContent() {
        return content;
    }

    public void setContent(Content content) {
        this.content = content;
    }

}


@Entity
@Table(name = "content")
public class Content {
    private Set<Content> subContents = new HashSet<Content>();

    @ManyToMany(fetch = FetchType.EAGER)
    @JoinTable(name = "subcontents", joinColumns = {@JoinColumn(name = "content_id")}, inverseJoinColumns = {@JoinColumn(name = "elt")})
    @Cascade(value = {org.hibernate.annotations.CascadeType.DELETE, org.hibernate.annotations.CascadeType.REPLICATE})
    @Fetch(value = FetchMode.SUBSELECT)
    public Set<Content> getSubContents() {
        return subContents;
    }

    public void setSubContents(Set<Content> subContents) {
        this.subContents = subContents;
    }

}

So a Package has a Content, and a Content is self-referencing in that it has many sub-Contents (which may contain sub-Contents of their own etc).

The relationships are required to be ManyToOne (Package to Content) and ManyToMany (Content to sub-Contents) but for the case I am currently testing each sub-Content only relates to one Package or Content.

The problem is that when I delete a Package and flush the session, I get a Hibernate error stating that I'm violating a foreign key constraint on table subcontents, with a particular content_id still referenced from table subcontents.

I've tried specifically (recursively) deleting the Contents before deleting the Package but I get the same error.

Is there a reason why this entity tree is not being deleted properly?