我做了一些研究，我发现一个人在下面有同样的问题（它在葡萄牙语中https://groups.google.com/forum/#!topic/javasf/OBPyBP6Sfjs）但是他提供的网站不再存在并且他两天没回我的邮件，所以...
问题是：每当我使用复合组件时，我都会遇到该异常（即使它们只是为了测试而为空）：
javax.servlet.ServletException：javax.faces.component.UIPanel 无法转换为 javax.faces.component.html.HtmlPanelGroup javax.faces.webapp.FacesServlet.service(FacesServlet.java:606) org.springframework.orm.jpa。 support.OpenEntityManagerInViewFilter.doFilterInternal(OpenEntityManagerInViewFilter.java:147) org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76) 根本原因
java.lang.ClassCastException：javax.faces.component.UIPanel 无法转换为 javax.faces.component.html.HtmlPanelGroup org.apache.myfaces.shared.renderkit.html.HtmlGroupRendererBase.encodeEnd(HtmlGroupRendererBase.java:65) javax。 faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:875) javax.faces.component.UIComponent.encodeAll(UIComponent.java:1786) org.apache.myfaces.renderkit.html.HtmlCompositeComponentRenderer.encodeEnd(HtmlCompositeComponentRenderer.java:71) javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:875) javax.faces.component.UIComponent.encodeAll(UIComponent.java:1786) javax.faces.component.UIComponent.encodeAll(UIComponent.java:1782) javax. faces.component.UIComponent.encodeAll(UIComponent.java:1782) com.sun.faces.application.view.FaceletViewHandlingStrategy。renderView(FaceletViewHandlingStrategy.java:402) org.apache.myfaces.application.ViewHandlerImpl.renderView(ViewHandlerImpl.java:285) com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:121) com.sun.faces。生命周期.Phase.doPhase(Phase.java:101) com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139) javax.faces.webapp.FacesServlet.service(FacesServlet.java:594) org.springframework。 orm.jpa.support.OpenEntityManagerInViewFilter.doFilterInternal(OpenEntityManagerInViewFilter.java:147) org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)121) com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139) javax.faces.webapp.FacesServlet.service(FacesServlet. java:594) org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter.doFilterInternal(OpenEntityManagerInViewFilter.java:147) org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)121) com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139) javax.faces.webapp.FacesServlet.service(FacesServlet. java:594) org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter.doFilterInternal(OpenEntityManagerInViewFilter.java:147) org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
对我来说，当你使用复合材料时，myfaces 会尝试生成一个面板，并且由于某种原因引发了异常，只是要记住我做了这个测试，身体只有复合材料，复合材料本身是空的（带接口和实施部分）。
我正在使用 Myfaces 2.1.11、tomcat 7（maven 插件）、jsf 2.0、hibernate。