GWT 2.5 breaks RPC method - fine on 2.4, but not working after upgrade

问题

After upgrade from GWT 2.4.0 to 2.5.0 only one of many (many!) RPC methods is broken and I have no idea why. Here is what happens (and what does not):

1. The program gets to async service object and calls its method.
2. Underyling, generated by GWT proxy object exists and is called (I don't know its internals, though).
3. The browser doesn't send any request to server (at least developer tools built into Google Chrome doesn't show anything like that happening. On the other hand... see 5.).
4. The implementation on server is never called.
5. If I stop the server, however, AsyncCallback.onFailure(Throwable) is executed immediately.

I'll repeat for sake of clarity: the very same code works like a charm on GWT 2.4.0 and other metods (most of them if not all) work just fine even on 2.5.0.

Now some code. Not sure if necessary, but...

Async interface

public interface BrokenServiceAsync {
    public void getData(int id, State state, AsyncCallback<Data> asyncCallback);
}

Both State interface (method param) and it's only implementation are declared in external module (added as jar package). I though this could be the case of that problem, but other methods are using these classes too. And there are no compile-time errors.

Data contains a String and an ArrayList of objects subclassing com.extjs.gxt.ui.client.data.BaseModelData. Most other methods use similar objects and it works.

Any ideas? Thanks!

来源：https://stackoverflow.com/questions/14346199/gwt-2-5-breaks-rpc-method-fine-on-2-4-but-not-working-after-upgrade