-1

我有三个代理接口：

IModuleBaseProxy
IBerichtModuleProxy extends IModuleBaseProxy
INewsModuleProxy extends IModuleBaseProxy

函数 clientfactory.getModule(id) 返回一个 IModuleBaseProxy

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

我有以下问题，而 1. 有效，2. 无效：

1.

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

2.

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

我得到以下异常：

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

完整的堆栈跟踪：

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)

有人明白这一点吗？

最善良的山姆

4

1 回答 1

0

好的，在没有看到您的代码的情况下，我会假设当您收到异常时，您返回了一个 INewsModuleProxy 并试图将其视为 IBerichtModuleProxy。为了向自己证明这一点，您可以在返回之前打印对象的类型。

我很想质疑您的设计，因为您的返回类型表明客户应该不关心具体的实现。如果这是真的，你为什么要低调？

R

于 2012-05-26T08:40:59.837 回答