Hibernate Composite primary key contains foreign key which is subset of other tables primary key, how to map?

The scenario is as follows

Table A has a composite PK.

Table A 
-------- 
 a1 (pk)开发者_JS百科
 a2 (pk)
 a3 (pk)
 foo
 bar
 LastUpdateDate
 LastUpdateUser
======== 

Table B has a composite PK too which is actually subset of A's PK, here is working as FK as well. There is no forced FK constraint.

Table B 
-------- 
 a1 (fk,pk) 
 a2 (fk,pk) 
 foo
 bar 
 LastUpdateDate
 LastUpdateUser
======== 

I tried several ways, and none of them works. Can anyone tell a working Hibernate mapping solution? better in annotation style.

Thanks a lot.

Viv

I can see following set up. Although it may be tricky to get to work and, based on my experience, it's unnecessary complexity.

class A implements Serializable {
   @Id
   private PK id = new PK();
   @Embeddable      
    public static final class PK implements Serializable {
        @ManyToOne 
        @JoinColumns ({
        @JoinColumn(name="A1_COL", referencedColumnName = "id.a1"),
        @JoinColumn(name="A2_COL", referencedColumnName = "id.a2"),

        })
         B b;            
        @Basic String a3;
    }    
 }


class B implements Serializable {
   @Id
   private PK id = new PK();
   @Embeddable      
    public static final class PK implements Serializable {                    
        @Basic String a1;
        @Basic String a2;
        @Basic String a3;
    }    
 }

You should be able to access be via

a.getId().getB()

Add setters/getters as necessary.

Usually this type of problems requires a lot of trial and error, so don't expect this to work right away. But that should give you a direction for digging. Once you nail down final configuration, please add it to you question so somebody can benefit from it in future.