I\'ve just started learning Google Web Toolkit and finished writing the Stock Watcher tutorial app.
Is my thinking correct that if one wants to persist a bus
The short answer is: you don't need to create duplicate classes.
I recommend that you take a look from the following google groups discussion on the gwt-contributors list:
http://groups.google.com/group/google-web-toolkit-contributors/browse_thread/thread/3c768d8d33bfb1dc/5a38aa812c0ac52b
Here is an interesting excerpt:
If this is all you're interested in, I described a way to make GAE and GWT-RPC work together "out of the box". Just declare your entities as: @PersistenceCapable(identityType = IdentityType.APPLICATION, detachable = "false") public class MyPojo implements Serializable { }
and everything will work, but you'll have to manually deal with re-attachment when sending objects from the client back to the server.
You can use this option, and you will not need a mirror (DTO) class. You can also try gilead (former hibernate4gwt), which takes care of some details within the problems of serializing enhanced objects.