Failing to complete RPC when using one parameter

[Bugs]

I am having problems getting RPC to work when I pass one parameter. I tried to use String etc, but it still fails. It works if no parmeter is passed to the getCars method.

ExampleService


@RemoteServiceRelativePath("exampleService")
public interface ExampleService extends RemoteService {
List<Car> getCars(Car car);
}

// Car extends BaseModelData.
ExampleServiceAsync


public interface ExampleServiceAsync {
void getCars(Car car, AsyncCallback<List<Car>> cars);
}
And the code to the uses RPC


RpcProxy<Car, List<Car>> proxy = new RpcProxy<Car, List<Car>>() {
@Override
protected void load(Car car, AsyncCallback<List<Car>> cars) {
service.getCars(car, cars);
}
};

ListLoader loader = new BaseListLoader(proxy);
ListStore<Car> store = new ListStore<Car>(loader);

ComboBox<Car> combo = new ComboBox<Car>();
combo.setFieldLabel("Car");
combo.setDisplayField("name");
combo.setStore(store);

// example code
loader.load(new Car("test"));


The service implementation gill receive a Car object, but it fails to display any items in the combobox. It gives me a java.lang.ClassCastException. Seems like I am missing something here... :s

[fother]

post the full stacktrace..

[Bugs]

This is the stacktrace. As mentioned above, the code works fine without any parameter



ERROR] Uncaught exception escaped
java.lang.RuntimeException: java.lang.ClassCastException: com.example.test.client.model.Car
at com.extjs.gxt.ui.client.store.ListStore.onLoadException(ListStore.java:466)
at com.extjs.gxt.ui.client.store.ListStore$1.loaderLoadException(ListStore.java:135)
at com.extjs.gxt.ui.client.event.LoadListener.handleEvent(LoadListener.java:27)
at com.extjs.gxt.ui.client.event.LoadListener.handleEvent(LoadListener.java:1)
at com.extjs.gxt.ui.client.event.BaseObservable.fireEvent(BaseObservable.java:74)
at com.extjs.gxt.ui.client.data.BaseLoader.onLoadFailure(BaseLoader.java:155)
at com.extjs.gxt.ui.client.data.BaseLoader$1.onFailure(BaseLoader.java:115)
at com.extjs.gxt.ui.client.data.RpcProxy$1.onSuccess(RpcProxy.java:35)
at com.google.gwt.user.client.rpc.impl.RequestCallbackAdapter.onResponseReceived(RequestCallbackAdapter.java:215)
at com.google.gwt.http.client.Request.fireOnResponseReceivedImpl(Request.java:254)
at com.google.gwt.http.client.Request.fireOnResponseReceivedAndCatch(Request.java:226)
at com.google.gwt.http.client.Request.fireOnResponseReceived(Request.java:217)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
at com.google.gwt.dev.shell.mac.MethodDispatch.invoke(MethodDispatch.java:71)
at org.eclipse.swt.internal.carbon.OS.ReceiveNextEvent(Native Method)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:2909)
at com.google.gwt.dev.GWTShell.pumpEventLoop(GWTShell.java:720)
at com.google.gwt.dev.GWTShell.run(GWTShell.java:593)
at com.google.gwt.dev.GWTShell.main(GWTShell.java:357)
Caused by: java.lang.ClassCastException: com.example.test.client.model.Car
at com.extjs.gxt.ui.client.store.ListStore.onLoad(ListStore.java:428)
at com.extjs.gxt.ui.client.store.ListStore$1.loaderLoad(ListStore.java:131)
at com.extjs.gxt.ui.client.event.LoadListener.handleEvent(LoadListener.java:24)
at com.extjs.gxt.ui.client.event.LoadListener.handleEvent(LoadListener.java:1)
at com.extjs.gxt.ui.client.event.BaseObservable.fireEvent(BaseObservable.java:74)
at com.extjs.gxt.ui.client.data.BaseLoader.onLoadSuccess(BaseLoader.java:166)
at com.extjs.gxt.ui.client.data.BaseLoader$1.onSuccess(BaseLoader.java:119)
at com.extjs.gxt.ui.client.data.RpcProxy$1.onSuccess(RpcProxy.java:33)
at com.google.gwt.user.client.rpc.impl.RequestCallbackAdapter.onResponseReceived(RequestCallbackAdapter.java:215)
at com.google.gwt.http.client.Request.fireOnResponseReceivedImpl(Request.java:254)
at com.google.gwt.http.client.Request.fireOnResponseReceivedAndCatch(Request.java:226)
at com.google.gwt.http.client.Request.fireOnResponseReceived(Request.java:217)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
at com.google.gwt.dev.shell.mac.MethodDispatch.invoke(MethodDispatch.java:71)
at org.eclipse.swt.internal.carbon.OS.ReceiveNextEvent(Native Method)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:2909)
at com.google.gwt.dev.GWTShell.pumpEventLoop(GWTShell.java:720)
at com.google.gwt.dev.GWTShell.run(GWTShell.java:593)
at com.google.gwt.dev.GWTShell.main(GWTShell.java:357)


Car extends BaseModelData.

[Bugs]

Eclipse gives me the following hint

"The method load(Object) belongs to the raw type Loader. References to a generic type Loader<C> should be parameterized"

So I changed this


ListLoader loader = new BaseListLoader(proxy);


to this


ListLoader<Car> loader = new BaseListLoader(proxy);


But this will fail, since ListLoader has the following defintion:

"ListLoader<C extends ListLoadConfig>"

I then changed Car to to extend BaseListLoadConfig and the compiler was happy. Though to be honest, I am not sure this is correct at all...

I am sure that most people already figured this out, any help is appreciated.

Thank you.

[Bugs]

Problem is solved.

The solution was to let the Car extend BaseListLoadConfig instead.

The Cars would then be successfully loaded.

The next problem was that the ComboBox would re-fetch the Cars once clicked, and I assume that it then called Loader.load() without any argument causing a crash.

This is a subject for another thread though.

~o)