Vaadin RPC with complex data !

Hello,
is possible use vaadin rpc with complex data (e.g classes ) ? I mean read vaadin RPC based on GWT RPC … this use isSerializable …

in book found only :
“You can pass the most common standard Java types, such as primitive and boxed primitive types, String, and arrays and some collections (List, Set, and Map) of the supported types. Also the Vaadin Connector and some special internal types can be passed.”

If I try this with my class but I get always error in connector :
SEVERE: Error performing server to client RPC callscom.google.gwt.core.client.JavaScriptException: (TypeError) : Cannot read property ‘getFirstName’ of null …

Regards

Newer one known ?
Small answer is first enough… yes or no ?.. look eg…

For a class to be used in an RPC or a shared state it has to be available to both the Server- and the Client-side. Built-In classes that are can be found in the com.vaadin.shared package.
If you want to use your own class try putting it in the same package as your RPC class which should get compiled to the client side when (re)compiling the widgetset.
I’m not 100% sure though as I’ve never tried it.
You should also have a look at this thread:
https://vaadin.com/forum#!/thread/2181029
. It’s about using the Component class and further down using custom classes in SharedStates. The same should apply to RPCs