JPAVariablePersister will not work when @Id is declared on a superclass

Given A and B:

@MappedSuperclass
public class A {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id = null;
}

@Entity
public class B extends A {
// Some other fields
}

In JPAVariablePersister:getClassIdValue, the code introspects the entity class to autodetect the @Id annotation. The code fails in this case since the annotation is declared on the superclass, and the current implementation only loops on the local fields of class B.

I tested the following implementation of getClassIdValue to work (loop on parent class objects)

private Long getClassIdValue(Object o)
throws NoSuchMethodException, SecurityException,
IllegalAccessException, InvocationTargetException,
IllegalArgumentException {
Class<?> c = o.getClass();
Long idValue = null;
do {
Field fields[] = c.getDeclaredFields();
for (int i = 0; i < fields.length; i++) {
Id id = fields[i].getAnnotation(Id.class);
if (id != null) {
idValue = (Long) o.getClass().getMethod(
"get"
+ Character.toUpperCase(fields[i]
.getName().charAt(0))
+ fields[i].getName().substring(1),
new Class<?>[] {}).invoke(o,
new Object[] {});
break;
}
}
} while ((c = c.getSuperclass()) != null && idValue == null);

return idValue;
}

Actually this type of code should probably deserve a service function somewhere...