I have a join table schema relationship represented by OneToMany and ManyToOne associations and am having some trouble getting Hibernate to respect the not-null constraints on the foreign keys.

The schema is similar to the following:
TableA
PKA
<columns A>

Table AB (join table -- two columns as PK)
<PKAB1> (FK to Table A) <-- not-null
<PKAB2> (FK to Table B) <-- not-null
<columns AB>

TableB
PKB
<columns B>


I am using Hibernate Annotations to represent a portion of this as shown below with object A being the owning side of this bi-directional association.

In Object A
@OneToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER)
@Cascade(org.hibernate.annotations.CascadeType.DELETE_ORPHAN)
@JoinColumn(name = "PKAB1", nullable = false)
@IndexColumn(name = "position")
List<AB> getABs()
{
return mTheList;
}

void setABs(List<AB> pTheList)
{
ValidateNoNullElements(pTheList); <-- this is how I know the not-null constraint is not working.
mTheList = pTheList;
}

In Object AB
@ManyToOne
@JoinColumn(name = "PKA", nullable = false, insertable = false, updatable = false)

I read in another post from someone modifying .hbm.xml files directly that the not-null constraint needs to go on the key xml element. I confirmed through hbm2hbmxml that the not-null constraint was not going on the key xml element; though, I have not found a solution through Annotations on how to put it there. The not-null constraint is constantly being placed on the column xml element instead of the key.

Any help would be greatly appreciated!

I suppose a simpler query to the above statement can be made in how can one specify attributes of the key element using annotations?