-1

私は3つのプロキシインターフェースを持っています:

IModuleBaseProxy
IBerichtModuleProxy extends IModuleBaseProxy
INewsModuleProxy extends IModuleBaseProxy

関数 clientfactory.getModule(id) は IModuleBaseProxy を返します

public IModuleBaseProxy getModule(String id) {
    return moduleList.get(id);
}

次の問題がありますが、1. は機能しますが、2. は機能しません:

1.

INewsModuleProxy nm = (INewsModuleProxy) clientfactory.getModule(id);

2.

IBerichtModuleProxy bm =(IBerichtModuleProxy) clientfactory.getModule(id);

次の例外が発生します。

Caused by: java.lang.ClassCastException: ch.zhaw.ams.client.core.module.IModuleBaseProxyAutoBean_com_google_web_bindery_requestfactory_shared_impl_EntityProxyCategory_com_google_web_bindery_requestfactory_shared_impl_ValueProxyCategory_com_google_web_bindery_requestfactory_shared_impl_BaseProxyCategory$1 cannot be cast to ch.zhaw.ams.module.football.sfv.bericht.client.IBerichtModuleProxy

完全なスタック トレース:

14:21:50.922 [ERROR] [simpleams] Uncaught exception escaped

com.google.web.bindery.event.shared.UmbrellaException: One or more exceptions caught, see full set in UmbrellaException#getCauses
    at com.google.web.bindery.requestfactory.shared.impl.AbstractRequestContext$StandardPayloadDialect.processPayload(AbstractRequestContext.java:387)
    at com.google.web.bindery.requestfactory.shared.impl.AbstractRequestContext$5.onTransportSuccess(AbstractRequestContext.java:1108)
    at ch.zhaw.ams.client.core.AmsRequestTransport$1.onTransportSuccess(AmsRequestTransport.java:30)
    at com.google.web.bindery.requestfactory.gwt.client.DefaultRequestTransport$1.onResponseReceived(DefaultRequestTransport.java:136)
    at com.google.gwt.http.client.Request.fireOnResponseReceived(Request.java:287)
    at com.google.gwt.http.client.RequestBuilder$1.onReadyStateChange(RequestBuilder.java:395)
    at sun.reflect.GeneratedMethodAccessor77.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
    at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
    at com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:172)
    at com.google.gwt.dev.shell.BrowserChannelServer.reactToMessagesWhileWaitingForReturn(BrowserChannelServer.java:337)
    at com.google.gwt.dev.shell.BrowserChannelServer.invokeJavascript(BrowserChannelServer.java:218)
    at com.google.gwt.dev.shell.ModuleSpaceOOPHM.doInvoke(ModuleSpaceOOPHM.java:136)
    at com.google.gwt.dev.shell.ModuleSpace.invokeNative(ModuleSpace.java:561)
    at com.google.gwt.dev.shell.ModuleSpace.invokeNativeObject(ModuleSpace.java:269)
    at com.google.gwt.dev.shell.JavaScriptHost.invokeNativeObject(JavaScriptHost.java:91)
    at com.google.gwt.core.client.impl.Impl.apply(Impl.java)
    at com.google.gwt.core.client.impl.Impl.entry0(Impl.java:213)
    at sun.reflect.GeneratedMethodAccessor28.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
    at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
    at com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:172)
    at com.google.gwt.dev.shell.BrowserChannelServer.reactToMessages(BrowserChannelServer.java:292)
    at com.google.gwt.dev.shell.BrowserChannelServer.processConnection(BrowserChannelServer.java:546)
    at com.google.gwt.dev.shell.BrowserChannelServer.run(BrowserChannelServer.java:363)
    at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.ClassCastException: ch.zhaw.ams.client.core.module.IModuleBaseProxyAutoBean_com_google_web_bindery_requestfactory_shared_impl_EntityProxyCategory_com_google_web_bindery_requestfactory_shared_impl_ValueProxyCategory_com_google_web_bindery_requestfactory_shared_impl_BaseProxyCategory$1 cannot be cast to ch.zhaw.ams.module.football.sfv.bericht.client.IBerichtModuleProxy
    at ch.zhaw.ams.module.football.sfv.bericht.client.presenter.ams.BerichtPresenter.<init>(BerichtPresenter.java:74)
    at ch.zhaw.ams.client.ams.IReflectiveAmsFactoryWrapper.newInstance(IReflectiveAmsFactoryWrapper.java:5)
    at ch.zhaw.ams.client.ams.presenter.AmsPresenter$1.onSuccess(AmsPresenter.java:124)
    at ch.zhaw.ams.client.ams.presenter.AmsPresenter$1.onSuccess(AmsPresenter.java:1)
    at com.google.web.bindery.requestfactory.shared.impl.AbstractRequest.onSuccess(AbstractRequest.java:129)
    at com.google.web.bindery.requestfactory.shared.impl.AbstractRequestContext$StandardPayloadDialect.processPayload(AbstractRequestContext.java:354)
    at com.google.web.bindery.requestfactory.shared.impl.AbstractRequestContext$5.onTransportSuccess(AbstractRequestContext.java:1108)
    at ch.zhaw.ams.client.core.AmsRequestTransport$1.onTransportSuccess(AmsRequestTransport.java:30)
    at com.google.web.bindery.requestfactory.gwt.client.DefaultRequestTransport$1.onResponseReceived(DefaultRequestTransport.java:136)
    at com.google.gwt.http.client.Request.fireOnResponseReceived(Request.java:287)
    at com.google.gwt.http.client.RequestBuilder$1.onReadyStateChange(RequestBuilder.java:395)
    at sun.reflect.GeneratedMethodAccessor77.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
    at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
    at com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:172)
    at com.google.gwt.dev.shell.BrowserChannelServer.reactToMessagesWhileWaitingForReturn(BrowserChannelServer.java:337)
    at com.google.gwt.dev.shell.BrowserChannelServer.invokeJavascript(BrowserChannelServer.java:218)
    at com.google.gwt.dev.shell.ModuleSpaceOOPHM.doInvoke(ModuleSpaceOOPHM.java:136)
    at com.google.gwt.dev.shell.ModuleSpace.invokeNative(ModuleSpace.java:561)
    at com.google.gwt.dev.shell.ModuleSpace.invokeNativeObject(ModuleSpace.java:269)
    at com.google.gwt.dev.shell.JavaScriptHost.invokeNativeObject(JavaScriptHost.java:91)
    at com.google.gwt.core.client.impl.Impl.apply(Impl.java)
    at com.google.gwt.core.client.impl.Impl.entry0(Impl.java:213)
    at sun.reflect.GeneratedMethodAccessor28.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
    at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
    at com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:172)
    at com.google.gwt.dev.shell.BrowserChannelServer.reactToMessages(BrowserChannelServer.java:292)
    at com.google.gwt.dev.shell.BrowserChannelServer.processConnection(BrowserChannelServer.java:546)
    at com.google.gwt.dev.shell.BrowserChannelServer.run(BrowserChannelServer.java:363)
    at java.lang.Thread.run(Thread.java:662)

誰かがポイントを見ますか？

親切なサム

4

1 に答える 1

0

OK、あなたのコードを見なくても、例外を受け取ったときに INewsModuleProxy を返し、それを IBerichtModuleProxy として処理しようとしていると思います。これを証明するために、オブジェクトを返す前にその型を出力できます。

あなたの戻り値の型は、クライアントが特定の実装に関心を持たないことを示唆しているため、あなたの設計に疑問を持ちたくなりました。これが本当なら、なぜあなたはダウンキャストをしているのですか?

R

于 2012-05-26T08:40:59.837 に答える