Hi all,

i have a OneToMany relationship in an @Entitiy



When i want to read this HashSet with:


i'm getting following exception:

java.lang.ClassCastException: java.util.HashSet cannot be cast to org.hibernate.collection.PersistentSet

i could use


but i dont want to use hibernate classes in my code because i want to use pure JPA.

Does anyone have an idea why i have to cast and how to avoid this situation

thank you very much

You should use Set, List, Map, etc. instead of concrete implementations.

should i use the code like this?

@OneToMany(cascade=CascadeType.ALL, orphanRemoval=true)
@JoinColumn(name="transaction_id")
private Set<MyData> myData= new Set<MyData>();


or what do you mean???

You can't do new Set() because that is an interface.

Here you should use Set and not HashSet (or PersistentSet):

Hi nordborg,

yes therefore i was asking, i didn't understand and couldn'T believe. I know that i can't create an instance from an interface....
i'll try it outan will reply later.
thank you very much

maxpade

Ok now it's working:

Set myData= MyData.getMyData();