Hi All,

I am just starting out on EJB3/hibernate and am having trouble implementing a generic findChildren API.

What I'd like is an API that looks something like this

public List findChildren(SomeEntity parent, String childrenProperty)


I do realize, we can do parent.getChildren() but I want a more dynamic way to get children of a given entity.


For eg. Given the following schema,

PARENT
==========
PARENT_ID PK


CHILD
=======
CHILD_ID PK
CHILD_NAME
PARENT_ID FK

I should be able call

List childList = HibernateAPI.findChildren(parent, "children");


Any help is appreciated.
Thanks,
Sridhar.

@SuppressWarnings("unchecked")
public List findChildren(Object parent, String children) {

SingleTableEntityPersister parentMetadata = (SingleTableEntityPersister) HibernateService.getSessionFactory().getClassMetadata(parent.getClass());
Object parentId = parentMetadata.getIdentifier(parent, EntityMode.POJO);
String parentTableName = parentMetadata.getConstraintOrderedTableNameClosure()[0];

Class childClass = null;
CollectionMetadata md = HibernateService.getSessionFactory().getCollectionMetadata(parent.getClass().getName()+"."+children);
if (md != null && md instanceof OneToManyPersister) {
OneToManyPersister otm = (OneToManyPersister) md;
SingleTableEntityPersister childMetadata = (SingleTableEntityPersister) otm.getElementPersister();
childClass = childMetadata.getConcreteProxyClass(EntityMode.POJO);
}
else {
throw new RuntimeException(parentTableName + " is not related(? to many) to " + children);
}


Criteria crit = getSession()

.createCriteria(childClass)
.createCriteria(parentTableName).add(Restrictions.idEq(parentId))
;

return crit.list();

}


Has tons of holes and does not handle join tables.


Anyone has better ideas?...Anyone?