In stateful session beans we are not allowed to use collections which are not serializable. I tested that by using HashTable and it indeed fails. My question is: what should I use in case I need to have a collection class. thanks. - walk rustin
HashTable itself is serializable. You have to make sure what you put in HashTable is serializable. Also, you should not use the collection than is returned by values() method, because what you get is something that implements Collection, but you do not know if that is serializable. Look at page 72 of HFEJB for more details.