JPAContainer how to filter on @ElementCollection of String

Vaadin 6 / 7 / 8 Framework Data Binding
1

Domain model is something like this:

public class ClassRoom {

@ElementCollection
private SetemailStudent;

…

I’d like to filter Classroom having some emailStudent, but now success yet, and I’m going crazy,
specially I don’t know what put “WHAT HERE?”

[code]

container.addContainerFilter(Filters.joinFilter(“emailStudent”, Filters.eq("
WHAT HERE?
", “special@special.com”)));
[/code]

Any help is appreciate.

Regards