问题描述
大家帮忙看看这是什么错误额。一直弄不出。错误：AnErrorOccurred:javax.faces.FacesException:java.lang.ClassCastException:$Proxy81cannotbecasttocn.edu.xmu.projecttrack.model.ForumFacadeCausedby:java.lang.ClassCastException-$Proxy81cannotbecasttocn.edu.xmu.projecttrack.model.ForumFacade+-StackTracejavax.faces.FacesException:javax.faces.FacesException:java.lang.ClassCastException:$Proxy81cannotbecasttocn.edu.xmu.projecttrack.model.ForumFacadeatorg.apache.myfaces.context.servlet.ServletExternalContextImpl.dispatch(ServletExternalContextImpl.java:347)atorg.apache.myfaces.application.jsp.JspViewHandlerImpl.buildView(JspViewHandlerImpl.java:486)atorg.apache.myfaces.application.jsp.JspViewHandlerImpl.renderView(JspViewHandlerImpl.java:337)atorg.apache.myfaces.lifecycle.RenderResponseExecutor.execute(RenderResponseExecutor.java:41)atorg.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:140)atjavax.faces.webapp.FacesServlet.service(FacesServlet.java:155)atorg.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)atorg.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)atorg.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)atorg.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)atorg.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)atorg.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)atorg.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)atorg.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:182)atorg.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84)atorg.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)atorg.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)atorg.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:157)atorg.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)atorg.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:262)atorg.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)atorg.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)atorg.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:446)atjava.lang.Thread.run(Thread.java:619)Causedby:org.apache.jasper.JasperException:javax.faces.FacesException:java.lang.ClassCastException:$Proxy81cannotbecasttocn.edu.xmu.projecttrack.model.ForumFacadeatorg.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:521)atorg.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:415)atorg.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:336)atorg.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)atjavax.servlet.http.HttpServlet.service(HttpServlet.java:803)atorg.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)atorg.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)atorg.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:654)atorg.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:445)atorg.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:379)atorg.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:292)atorg.apache.myfaces.context.servlet.ServletExternalContextImpl.dispatch(ServletExternalContextImpl.java:341)...23moreCausedby:javax.faces.FacesException:java.lang.ClassCastException:$Proxy81cannotbecasttocn.edu.xmu.projecttrack.model.ForumFacadeatorg.apache.myfaces.application.ApplicationImpl.createComponent(ApplicationImpl.java:329)atjavax.faces.webapp.UIComponentELTag.createComponent(UIComponentELTag.java:94)atjavax.faces.webapp.UIComponentClassicTagBase.findComponent(UIComponentClassicTagBase.java:1104)atjavax.faces.webapp.UIComponentClassicTagBase.doStartTag(UIComponentClassicTagBase.java:434)atorg.apache.jsp.forum.forumPage_jsp._jspx_meth_h_005fdataTable_005f0(forumPage_jsp.java:720)atorg.apache.jsp.forum.forumPage_jsp._jspx_meth_h_005fpanelGrid_005f1(forumPage_jsp.java:596)atorg.apache.jsp.forum.forumPage_jsp._jspx_meth_h_005fform_005f0(forumPage_jsp.java:531)atorg.apache.jsp.forum.forumPage_jsp._jspx_meth_h_005fpanelGrid_005f0(forumPage_jsp.java:488)atorg.apache.jsp.forum.forumPage_jsp._jspService(forumPage_jsp.java:155)atorg.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)atjavax.servlet.http.HttpServlet.service(HttpServlet.java:803)atorg.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:373)...33moreCausedby:java.lang.ClassCastException:$Proxy81cannotbecasttocn.edu.xmu.projecttrack.model.ForumFacadeatcn.edu.xmu.projecttrack.view.util.Utils.getForumFacade(Utils.java:178)atcn.edu.xmu.projecttrack.view.ForumPage.<init>(ForumPage.java:26)atsun.reflect.NativeConstructorAccessorImpl.newInstance0(NativeMethod)atsun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)atsun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)atjava.lang.reflect.Constructor.newInstance(Constructor.java:513)atjava.lang.Class.newInstance0(Class.java:355)atjava.lang.Class.newInstance(Class.java:308)atorg.apache.myfaces.config.annotation.TomcatAnnotationLifecycleProvider.newInstance(TomcatAnnotationLifecycleProvider.java:47)atorg.apache.myfaces.config.ManagedBeanBuilder.buildManagedBean(ManagedBeanBuilder.java:84)atorg.apache.myfaces.el.unified.resolver.ManagedBeanResolver.createManagedBean(ManagedBeanResolver.java:198)atorg.apache.myfaces.el.unified.resolver.ManagedBeanResolver.getValue(ManagedBeanResolver.java:164)atjavax.el.CompositeELResolver.getValue(CompositeELResolver.java:53)atorg.apache.myfaces.el.unified.resolver.FacesCompositeELResolver.getValue(FacesCompositeELResolver.java:140)atorg.apache.myfaces.el.VariableResolverImpl.resolveVariable(VariableResolverImpl.java:64)atorg.apache.myfaces.el.convert.VariableResolverToELResolver.getValue(VariableResolverToELResolver.java:95)atjavax.el.CompositeELResolver.getValue(CompositeELResolver.java:53)atorg.apache.myfaces.el.unified.resolver.FacesCompositeELResolver.getValue(FacesCompositeELResolver.java:140)atorg.apache.el.parser.AstIdentifier.getValue(AstIdentifier.java:45)atorg.apache.el.parser.AstValue.getValue(AstValue.java:86)atorg.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:186)atorg.apache.jasper.el.JspValueExpression.getValue(JspValueExpression.java:101)atorg.apache.myfaces.application.ApplicationImpl.createComponent(ApplicationImpl.java:307)...44more代码如下：View层：
<h:dataTablestyleClass="table-background"rowClasses="table-odd-row,table-even-row"cellpadding="3"value="#{forumPage.forumList}"var="forum"binding="#{forumPage.forumTable}"style="width:666px"><h:column><f:facetname="header"><h:outputTextvalue="论坛区"/><%--<f:paramname="column"value="name"/>--%></f:facet><h:outputTextvalue="#{forum.forumName}"/></h:column><h:column><f:facetname="header"><h:outputTextvalue="吧主"/><%--<f:paramname="column"value="type"/>--%></f:facet><h:outputTextvalue="#{forum.founder}"/></h:column><h:column><f:facetname="header"><h:outputTextvalue="帖子数"/><%--<f:paramname="column"value="numberOfPost"/>--%></f:facet><h:outputTextvalue="#{forum.numberOfPost}"/></h:column><h:column><f:facetname="header"><h:outputTextvalue="描述"/><%--<f:paramname="column"value="numberOfPost"/>--%></f:facet><h:outputTextvalue="#{forum.forumContent}"/></h:column></h:dataTable>ManagedBean:
publicForumPage(){ForumFacadefacade=null;try{facade=Utils.getForumFacade();}catch(NamingExceptione){//TODOAuto-generatedcatchblocke.printStackTrace();}}//-----------------------------set/get-------------------------------publicUIDatagetForumTable(){returnforumTable;}publicvoidsetForumTable(UIDataforumTable){this.forumTable=forumTable;}//------------------------------------------------------------------------/***获取论坛列表*@returnList<Forum>论坛列表*/publicList<Forum>getForumList(){ForumFacadefacade=null;try{facade=Utils.getForumFacade();}catch(NamingExceptiond){Utils.reportError(this.getFacesContext(),"ErrorFindingEJB",d);returnnewArrayList(0);}ForumTypetype=ForumType.CourseForum;intid=1;returnfacade.getForumList(type,id);}Client接口层：publicList<Forum>getForumList(ForumTypetype,intid);实现层：publicList<Forum>getForumList(ForumTypetype,intid){Stringsqlstr="SELECTfFROMForumfWHEREf.type=:typeandf.id=:id";Queryquery=em.createQuery(sqlstr);query.setParameter("type",type);query.setParameter("id",id);returnquery.getResultList();}弄了很久一直不对。好迷茫额。谢谢各位帮忙看看。
解决方案
解决方案二：
好抓狂啊。有没有哥哥姐姐会的额