How to call the method in Vaadin from a javascript click event?

someone can show me some directions?

I have tried JSNI, this is must used?
how about AJAX or RPC?

I want to trigger the click event in client javascript method
the call the method in vaadin

from client, only element id can be passed to server side.
code segment:

fwd.wrapper.click(function() {
//proc.containerInstance.displayDetail(fwd.cellId);

}

I need to get some Class A through cellId, then set the properties of A by A.getB() to show in other Vaadin compent,such as : STextField