JPA 2.1 Foreign Key isn't saving on ManyToOne cascade

Question

I have two classes.

public class Reservation {
    @OneToMany(cascade = CascadeType.ALL, orphanRemoval=true, mappedBy = "reservation")
    private List<Night> nights;  \\assume getters and setters
}

public class Night {
    @ManyToOne
    @JoinColumn(name = "RESERVATION_ID")
    private Reservation reservation;
}

My save works like this:

Reservation r = new Reservation();
r.getNights().add(new Night()); 
return dao.save(r);

This works, as in it saves the Reservation, and it saves the Night. But when I look at the database, the column RESERVATION_ID in the NIGHT table is null.

In previous projects (before upgrading to Java 8 and JPA 2.1), I didn't need to manually set the parent object on the child in order for that association to save. Did something change, or am I doing something wrong?

Edit:

This saves the association correctly, but it didn't used to be necessary.

Reservation r = new Reservation();
Night n = new Night();
n.setReservation(r);
r.getNights().add(n);
return dao.save(r);

Answer 1

According to JPA example provided in link below, you need to set the parent object in the child. You can do it in the Parent class (child's getter method)

http://en.wikibooks.org/wiki/Java_Persistence/OneToMany