Question

我们将 IBM WebSphere Portal 与JSF结合使用。一个可怕的混合，一次又一次证明它的可怕。

最近我们遇到了一个问题，我们有一个带有链接的portlet到下载servlet （包含在相同的战争中）。此 servlet 尝试从 HttpSession 中读取某些属性，这些属性应该由 portlet 设置< APPLICATION_SCOPE中的em> PortletSession 。

但是，有时， servlet 无法读取 HttpSession 中的任何所需属性。这是我进行调查的原因。经过一些搜索后，我发现它只发生在

经过一些实验后，我在NullPointerException上拨打getAttributeNames(scope)时收到了PortletSession。 PortletSession是通过 faces context 从外部上下文获得的。我发现PortletSession实际上是com.ibm.faces.portlet.httpbridge.PortletSessionWrapper，显然应该包含实际的PortletSession。包含会话的内容显然是 null 。 PortletSessionWrapper的大多数方法都使用空检查来防范 NPE ，但getAttributeNames(scope)没有（如果你问我，那就是一个错误）。

现在是一个大问题：为什么上的（真实）PortletSession null 首次加载< / em> portlet ？

提供包装器的 jsf-protletbrdige 的META-INF：


Manifest-Version：1.0
Ant-Version：Apache Ant 1.7.1
  创建者：IBM公司
规范 - 标题：Java服务器   Faces
实现 - 标题：JSF Widget Library（JWL） - Portlet   桥实施 - 版本：JWL v3_1_5
  实施 - 供应商：IBM
Build-Version：20100212_0941
  建造日期：2010年2月12日
版权信息：版权所有（c）   2003,2008，国际商业机器公司。所有权利   保留

调用getAttributeNames（范围）方法时的堆栈跟踪：

[21-8-12 17:52:16:051 CEST] 00000041 servlet E com.ibm.ws.webcontainer.servlet.ServletWrapper service SRVE0068E: Uncaught exception created in one of the service methods of the servlet Header in application PA_mytestportlet. Exception created : javax.servlet.ServletException: javax.portlet.PortletException: /MyPortletView.jsp(105,9) '#{MyPortletView.productId}' Error reading 'productId' on type mytest.portal.testportlet.view.MyPortletViewBean at com.ibm.ws.portletcontainer.invoker.impl.PortletServlet.doDispatch(PortletServlet.java:361) at com.ibm.ws.portletcontainer.invoker.impl.PortletServletCollaboratorChainImpl.doCollaborator(PortletServletCollaboratorChainImpl.java:82) at com.ibm.isclite.container.collaborator.PortletServletCollaborator.doDispatch(PortletServletCollaborator.java:143) at com.ibm.ws.portletcontainer.invoker.impl.PortletServletCollaboratorChainImpl.doCollaborator(PortletServletCollaboratorChainImpl.java:74) at com.ibm.ws.portletcontainer.rrd.RRDServerPortletServletCollaborator.doDispatch(RRDServerPortletServletCollaborator.java:60) at com.ibm.ws.portletcontainer.invoker.impl.PortletServletCollaboratorChainImpl.doCollaborator(PortletServletCollaboratorChainImpl.java:74) at com.ibm.ws.portletcontainer.cache.CacheCollaborator.doDispatch(CacheCollaborator.java:74) at com.ibm.ws.portletcontainer.invoker.impl.PortletServletCollaboratorChainImpl.doCollaborator(PortletServletCollaboratorChainImpl.java:74) at com.ibm.wps.pe.pc.waspc.core.impl.PortletServletCollaboratorImpl.doDispatch(PortletServletCollaboratorImpl.java:121) at com.ibm.ws.portletcontainer.invoker.impl.PortletServletCollaboratorChainImpl.doCollaborator(PortletServletCollaboratorChainImpl.java:74) at com.ibm.ws.portletcontainer.invoker.impl.PortletServlet.dispatch(PortletServlet.java:208) at com.ibm.ws.portletcontainer.invoker.impl.PortletServlet.service(PortletServlet.java:165) at javax.servlet.http.HttpServlet.service(HttpServlet.java:831) at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1657) at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1597) at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:104) at com.ibm.ws.webcontainer.filter.WebAppFilterChain._doFilter(WebAppFilterChain.java:77) at com.ibm.ws.webcontainer.filter.WebAppFilterManager.doFilter(WebAppFilterManager.java:908) at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:934) at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:502) at com.ibm.ws.webcontainer.servlet.ServletWrapperImpl.handleRequest(ServletWrapperImpl.java:179) at com.ibm.wsspi.webcontainer.servlet.GenericServletWrapper.handleRequest(GenericServletWrapper.java:121) at com.ibm.ws.portletcontainer.webextension.PortletExtensionProcessor.handleRequest(PortletExtensionProcessor.java:86) at com.ibm.ws.webcontainer.webapp.WebAppRequestDispatcher.include(WebAppRequestDispatcher.java:686) at com.ibm.ws.portletcontainer.invoker.impl.PortletInvokerImpl.invoke(PortletInvokerImpl.java:214) at com.ibm.ws.portletcontainer.invoker.impl.PortletInvokerCollaboratorChainImpl.doCollaborator(PortletInvokerCollaboratorChainImpl.java:78) at com.ibm.ws.portletcontainer.cache.PortletInvokerCacheCollaborator.doRender(PortletInvokerCacheCollaborator.java:58) at com.ibm.ws.portletcontainer.invoker.impl.PortletInvokerCollaboratorChainImpl.doCollaborator(PortletInvokerCollaboratorChainImpl.java:67) at com.ibm.ws.portletcontainer.ext.PortletInvokerPerformanceCollaborator.invoke(PortletInvokerPerformanceCollaborator.java:313) at com.ibm.ws.portletcontainer.ext.PortletInvokerPerformanceCollaborator.doInvoke(PortletInvokerPerformanceCollaborator.java:101) at com.ibm.ws.portletcontainer.ext.PortletInvokerPerformanceCollaborator.invokePMI(PortletInvokerPerformanceCollaborator.java:163) at com.ibm.ws.portletcontainer.ext.PortletInvokerPerformanceCollaborator.doInvoke(PortletInvokerPerformanceCollaborator.java:91) at com.ibm.ws.portletcontainer.ext.PortletInvokerPerformanceCollaborator.doRender(PortletInvokerPerformanceCollaborator.java:74) at com.ibm.ws.portletcontainer.invoker.impl.PortletInvokerCollaboratorChainImpl.doCollaborator(PortletInvokerCollaboratorChainImpl.java:67) at com.ibm.ws.portletcontainer.invoker.impl.PortletInvokerImpl.render(PortletInvokerImpl.java:97) at com.ibm.ws.portletcontainer.PortletContainerImpl.doRender(PortletContainerImpl.java:121) at com.ibm.ws.portletcontainer.PortletContainerInvokerCollaboratorChainImpl.doCollaborator(PortletContainerInvokerCollaboratorChainImpl.java:80) at com.ibm.ws.portletcontainer.ext.ExtCollaborator.doRender(ExtCollaborator.java:74) at com.ibm.ws.portletcontainer.PortletContainerInvokerCollaboratorChainImpl.doCollaborator(PortletContainerInvokerCollaboratorChainImpl.java:67) at com.ibm.ws.portletcontainer.cache.CacheInvokerCollaborator.doRender(CacheInvokerCollaborator.java:66) at com.ibm.ws.portletcontainer.PortletContainerInvokerCollaboratorChainImpl.doCollaborator(PortletContainerInvokerCollaboratorChainImpl.java:67) at com.ibm.ws.portletcontainer.PortletContainerImpl.renderPortlet(PortletContainerImpl.java:91) at com.ibm.ws.portletcontainer.pcinvoker.PortletInvokerImpl$2.run(PortletInvokerImpl.java:100) at java.security.AccessController.doPrivileged(AccessController.java:251) at com.ibm.ws.portletcontainer.pcinvoker.PortletInvokerImpl.invokeRender(PortletInvokerImpl.java:96) at com.ibm.wps.pe.pc.waspc.core.impl.PortletInvokerImpl$1.invoke(PortletInvokerImpl.java:98) at com.ibm.wps.pe.pc.waspc.core.impl.PortletInvokerImpl.invoke(PortletInvokerImpl.java:181) at com.ibm.wps.pe.pc.waspc.core.impl.PortletInvokerImpl.invokeRender(PortletInvokerImpl.java:96) at com.ibm.wps.pe.pc.waspc.PortletContainerImpl.renderPortlet(PortletContainerImpl.java:116) at com.ibm.wps.pe.pc.PortletContainerImpl.doRenderPortlet(PortletContainerImpl.java:641) at com.ibm.wps.pe.ext.render.AbstractRenderManager.performService(AbstractRenderManager.java:264) at com.ibm.wps.pe.pc.PortletContainerImpl.renderPortlet(PortletContainerImpl.java:132) at com.ibm.wps.engine.tags.PortletRenderTag.doStartTag(PortletRenderTag.java:179) at com.ibm._jsp._Control._jspx_meth_portal$1skin_portletRender_0(_Control.java:276) at com.ibm._jsp._Control._jspx_meth_portal$1logic_if_1(_Control.java:315) at com.ibm._jsp._Control._jspService(_Control.java:168) at com.ibm.ws.jsp.runtime.HttpJspBase.service(HttpJspBase.java:99) at javax.servlet.http.HttpServlet.service(HttpServlet.java:831) at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1657) at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:939) at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:502) at com.ibm.ws.webcontainer.servlet.ServletWrapperImpl.handleRequest(ServletWrapperImpl.java:179) at com.ibm.wsspi.webcontainer.servlet.GenericServletWrapper.handleRequest(GenericServletWrapper.java:121) at com.ibm.ws.jsp.webcontainerext.AbstractJSPExtensionServletWrapper.handleRequest(AbstractJSPExtensionServletWrapper.java:259) at com.ibm.ws.webcontainer.webapp.WebAppRequestDispatcher.include(WebAppRequestDispatcher.java:686) at com.ibm.wps.services.dispatcher.DispatcherServiceImpl.handleRequest(DispatcherServiceImpl.java:93) at com.ibm.wps.services.dispatcher.DispatcherServiceImpl.include(DispatcherServiceImpl.java:53) at com.ibm.wps.services.dispatcher.Dispatcher.include(Dispatcher.java:50) at com.ibm.wps.engine.templates.skins.Default.render(Default.java:154) at com.ibm.wps.engine.templates.SkinTemplate.render(SkinTemplate.java:68) at com.ibm.wps.composition.elements.Component.render(Component.java:638) at com.ibm.wps.composition.elements.Control.render(Control.java:159) at com.ibm.wps.composition.Composition.render(Composition.java:3102) at com.ibm.wps.composition.Composition.render(Composition.java:163) at com.ibm.websphere.personalization.transformation.PznTransformationLayoutModel.render(PznTransformationLayoutModel.java:90) at com.ibm.wps.model.wrappers.LayoutModelWrapperFactoryImpl$LayoutModelWrapperImpl.render(LayoutModelWrapperFactoryImpl.java:275) at com.ibm.wps.model.ModelUtil$WrappedCompositionModel.render(ModelUtil.java:1124) at com.ibm._jsp._UnlayeredContainer_2D_H._jspService(_UnlayeredContainer_2D_H.java:224) at com.ibm.ws.jsp.runtime.HttpJspBase.service(HttpJspBase.java:99) at javax.servlet.http.HttpServlet.service(HttpServlet.java:831) at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1657) at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:939) at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:502) at com.ibm.ws.webcontainer.servlet.ServletWrapperImpl.handleRequest(ServletWrapperImpl.java:179) at com.ibm.wsspi.webcontainer.servlet.GenericServletWrapper.handleRequest(GenericServletWrapper.java:121) at com.ibm.ws.jsp.webcontainerext.AbstractJSPExtensionServletWrapper.handleRequest(AbstractJSPExtensionServletWrapper.java:259) at com.ibm.ws.webcontainer.webapp.WebAppRequestDispatcher.include(WebAppRequestDispatcher.java:686) at com.ibm.wps.services.dispatcher.DispatcherServiceImpl.handleRequest(DispatcherServiceImpl.java:93) at com.ibm.wps.services.dispatcher.DispatcherServiceImpl.include(DispatcherServiceImpl.java:53) at com.ibm.wps.services.dispatcher.Dispatcher.include(Dispatcher.java:50) at com.ibm.wps.engine.templates.skins.Default.render(Default.java:154) at com.ibm.wps.engine.templates.SkinTemplate.render(SkinTemplate.java:68) at com.ibm.wps.composition.elements.Component.render(Component.java:638) at com.ibm.wps.composition.Composition.render(Composition.java:3102) at com.ibm.wps.composition.Composition.render(Composition.java:163) at com.ibm.websphere.personalization.transformation.PznTransformationLayoutModel.render(PznTransformationLayoutModel.java:90) at com.ibm.wps.model.wrappers.LayoutModelWrapperFactoryImpl$LayoutModelWrapperImpl.render(LayoutModelWrapperFactoryImpl.java:275) at com.ibm.wps.model.ModelUtil$WrappedCompositionModel.render(ModelUtil.java:1124) at com.ibm._jsp._UnlayeredContainer_2D_V._jspService(_UnlayeredContainer_2D_V.java:215) at com.ibm.ws.jsp.runtime.HttpJspBase.service(HttpJspBase.java:99) at javax.servlet.http.HttpServlet.service(HttpServlet.java:831) at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1657) at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:939) at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:502) at com.ibm.ws.webcontainer.servlet.ServletWrapperImpl.handleRequest(ServletWrapperImpl.java:179) at com.ibm.wsspi.webcontainer.servlet.GenericServletWrapper.handleRequest(GenericServletWrapper.java:121) at com.ibm.ws.jsp.webcontainerext.AbstractJSPExtensionServletWrapper.handleRequest(AbstractJSPExtensionServletWrapper.java:259) at com.ibm.ws.webcontainer.webapp.WebAppRequestDispatcher.include(WebAppRequestDispatcher.java:686) at com.ibm.wps.services.dispatcher.DispatcherServiceImpl.handleRequest(DispatcherServiceImpl.java:93) at com.ibm.wps.services.dispatcher.DispatcherServiceImpl.include(DispatcherServiceImpl.java:53) at com.ibm.wps.services.dispatcher.Dispatcher.include(Dispatcher.java:50) at com.ibm.wps.engine.templates.skins.Default.render(Default.java:154) at com.ibm.wps.engine.templates.SkinTemplate.render(SkinTemplate.java:68) at com.ibm.wps.composition.elements.Component.render(Component.java:638) at com.ibm.wps.composition.Composition.render(Composition.java:3102) at com.ibm.wps.composition.Composition.render(Composition.java:163) at com.ibm.websphere.personalization.transformation.PznTransformationLayoutModel.render(PznTransformationLayoutModel.java:90) at com.ibm.wps.model.wrappers.LayoutModelWrapperFactoryImpl$LayoutModelWrapperImpl.render(LayoutModelWrapperFactoryImpl.java:275) at com.ibm.wps.engine.tags2.PageRenderTag.doStartTag(PageRenderTag.java:534) at com.ibm._jsp._Home._jspService(_Home.java:104) at com.ibm.ws.jsp.runtime.HttpJspBase.service(HttpJspBase.java:99) at javax.servlet.http.HttpServlet.service(HttpServlet.java:831) at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1657) at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:939) at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:502) at com.ibm.ws.webcontainer.servlet.ServletWrapperImpl.handleRequest(ServletWrapperImpl.java:179) at com.ibm.wsspi.webcontainer.servlet.GenericServletWrapper.handleRequest(GenericServletWrapper.java:121) at com.ibm.ws.jsp.webcontainerext.AbstractJSPExtensionServletWrapper.handleRequest(AbstractJSPExtensionServletWrapper.java:259) at com.ibm.ws.webcontainer.webapp.WebAppRequestDispatcher.include(WebAppRequestDispatcher.java:686) at com.ibm.wps.services.dispatcher.DispatcherServiceImpl.handleRequest(DispatcherServiceImpl.java:93) at com.ibm.wps.services.dispatcher.DispatcherServiceImpl.include(DispatcherServiceImpl.java:53) at com.ibm.wps.services.dispatcher.Dispatcher.include(Dispatcher.java:50) at com.ibm.wps.engine.templates.screens.Default.render(Default.java:133) at com.ibm.wps.engine.templates.ScreenTemplate.render(ScreenTemplate.java:59) at com.ibm.wps.engine.tags2.ScreenRenderTag.doStartTag(ScreenRenderTag.java:182) at com.ibm._jsp._Default._jspx_meth_portal$1core_screenRender_0(_Default.java:3623) at com.ibm._jsp._Default._jspService(_Default.java:1966) at com.ibm.ws.jsp.runtime.HttpJspBase.service(HttpJspBase.java:99) at javax.servlet.http.HttpServlet.service(HttpServlet.java:831) at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1657) at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:939) at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:502) at com.ibm.ws.webcontainer.servlet.ServletWrapperImpl.handleRequest(ServletWrapperImpl.java:179) at com.ibm.wsspi.webcontainer.servlet.GenericServletWrapper.handleRequest(GenericServletWrapper.java:121) at com.ibm.ws.jsp.webcontainerext.AbstractJSPExtensionServletWrapper.handleRequest(AbstractJSPExtensionServletWrapper.java:259) at com.ibm.ws.webcontainer.webapp.WebAppRequestDispatcher.include(WebAppRequestDispatcher.java:686) at com.ibm.wps.services.dispatcher.DispatcherServiceImpl.handleRequest(DispatcherServiceImpl.java:93) at com.ibm.wps.services.dispatcher.DispatcherServiceImpl.include(DispatcherServiceImpl.java:53) at com.ibm.wps.services.dispatcher.Dispatcher.include(Dispatcher.java:50) at com.ibm.wps.engine.templates.themes.Default.doDispatch(Default.java:294) at com.ibm.wps.engine.templates.themes.Default.render(Default.java:247) at com.ibm.wps.engine.templates.ThemeTemplate.render(ThemeTemplate.java:65) at com.ibm.wps.engine.phases.WPRenderPhase.processRendering(WPRenderPhase.java:509) at com.ibm.wps.engine.phases.WPBaseRenderPhase.execute(WPBaseRenderPhase.java:194) at com.ibm.wps.state.phases.AbstractRenderPhase.next(AbstractRenderPhase.java:106) at com.ibm.wps.engine.phases.WPAbstractRenderPhase.next(WPAbstractRenderPhase.java:97) at com.ibm.wps.engine.Servlet.callPortal(Servlet.java:860) at com.ibm.wps.engine.Servlet.doGet(Servlet.java:617) at javax.servlet.http.HttpServlet.service(HttpServlet.java:718) at com.ibm.wps.engine.Servlet.doFilter(Servlet.java:1257) at com.ibm.wps.resolver.servlet.ContentHandlerCleanup.doFilter(ContentHandlerCleanup.java:648) at com.ibm.wps.resolver.servlet.AbstractFilter.doFilter(AbstractFilter.java:93) at com.ibm.wps.engine.Servlet.service(Servlet.java:1248) at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1657) at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1597) at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:131) at com.ibm.wps.engine.ExtendedLocaleFilter.doFilter(ExtendedLocaleFilter.java:113) at com.ibm.ws.webcontainer.filter.FilterInstanceWrapper.doFilter(FilterInstanceWrapper.java:188) at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:116) at com.ibm.wps.resolver.friendly.servlet.FriendlySelectionFilter.doFilter(FriendlySelectionFilter.java:191) at com.ibm.ws.webcontainer.filter.FilterInstanceWrapper.doFilter(FilterInstanceWrapper.java:188) at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:116) at com.ibm.wps.mappingurl.impl.URLAnalyzer.doFilter(URLAnalyzer.java:381) . . . Caused by: javax.portlet.PortletException: /MyPortletView.jsp(105,9) '#{MyPortletView.productId}' Error reading 'productId' on type mytest.portal.testportlet.view.MyPortletViewBean at com.ibm.faces.portlet.FacesPortlet.doRender(FacesPortlet.java:384) at com.ibm.faces.portlet.FacesPortlet.doView(FacesPortlet.java:413) at com.ibm.faces.portlet.FacesPortlet.doDispatch(FacesPortlet.java:301) at javax.portlet.GenericPortlet.render(GenericPortlet.java:233) at mytest.portal.testportlet.portlet.HeaderPortlet.render(HeaderPortlet.java:44) at com.ibm.ws.portletcontainer.invoker.impl.PortletFilterChainImpl.doFilter(PortletFilterChainImpl.java:128) at com.ibm.wps.propertybroker.standard.filter.C2APortletFilter.doFilter(C2APortletFilter.java:183) at com.ibm.ws.portletcontainer.invoker.impl.PortletFilterChainImpl.doFilter(PortletFilterChainImpl.java:120) at com.ibm.ws.portletcontainer.invoker.impl.PortletServlet.doDispatch(PortletServlet.java:573) at com.ibm.ws.portletcontainer.invoker.impl.PortletServletCollaboratorChainImpl.doCollaborator(PortletServletCollaboratorChainImpl.java:114) at com.ibm.isclite.container.collaborator.PortletServletCollaborator.doRender(PortletServletCollaborator.java:71) at com.ibm.ws.portletcontainer.invoker.impl.PortletServletCollaboratorChainImpl.doCollaborator(PortletServletCollaboratorChainImpl.java:105) at com.ibm.ws.portletcontainer.rrd.RRDServerPortletServletCollaborator.doRender(RRDServerPortletServletCollaborator.java:123) at com.ibm.ws.portletcontainer.invoker.impl.PortletServletCollaboratorChainImpl.doCollaborator(PortletServletCollaboratorChainImpl.java:105) at com.ibm.ws.portletcontainer.cache.CacheCollaborator.doRender(CacheCollaborator.java:92) at com.ibm.ws.portletcontainer.invoker.impl.PortletServletCollaboratorChainImpl.doCollaborator(PortletServletCollaboratorChainImpl.java:105) at com.ibm.wps.pe.pc.waspc.core.impl.PortletServletCollaboratorImpl.doRender(PortletServletCollaboratorImpl.java:156) at com.ibm.ws.portletcontainer.invoker.impl.PortletServletCollaboratorChainImpl.doCollaborator(PortletServletCollaboratorChainImpl.java:105) at com.ibm.ws.portletcontainer.invoker.impl.PortletServlet.doDispatch(PortletServlet.java:273) ... 203 more Caused by: org.apache.jasper.el.JspELException: /MyPortletView.jsp(105,9) '#{MyPortletView.productId}' Error reading 'productId' on type mytest.portal.testportlet.view.MyPortletViewBean at org.apache.jasper.el.JspValueExpression.getValue(JspValueExpression.java:106) at javax.faces.component.UIParameter.getValue(UIParameter.java:167) at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.getParamList(HtmlBasicRenderer.java:518) at com.sun.faces.renderkit.html_basic.OutputLinkRenderer.renderAsActive(OutputLinkRenderer.java:203) at com.sun.faces.renderkit.html_basic.OutputLinkRenderer.encodeBegin(OutputLinkRenderer.java:100) at com.ibm.faces.renderkit.DefaultAjaxRenderer.encodeBegin(DefaultAjaxRenderer.java:64) at javax.faces.component.UIComponentBase.encodeBegin(UIComponentBase.java:812) at mytest.jsf.util.ChildRendererUtil.renderChildren(ChildRendererUtil.java:45) at mytest.portal.ui.jsf.custom.component.htmltag.HtmlTagRenderer.encodeChildren(HtmlTagRenderer.java:110) at com.ibm.faces.renderkit.DefaultAjaxRenderer.encodeChildren(DefaultAjaxRenderer.java:73) at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:836) at mytest.jsf.util.ChildRendererUtil.renderChildren(ChildRendererUtil.java:47) at mytest.portal.ui.jsf.custom.component.htmltag.HtmlTagRenderer.encodeChildren(HtmlTagRenderer.java:110) at com.ibm.faces.renderkit.DefaultAjaxRenderer.encodeChildren(DefaultAjaxRenderer.java:73) at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:836) at mytest.jsf.util.ChildRendererUtil.renderChildren(ChildRendererUtil.java:47) at mytest.portal.ui.jsf.custom.component.htmltag.HtmlTagRenderer.encodeChildren(HtmlTagRenderer.java:110) at com.ibm.faces.renderkit.DefaultAjaxRenderer.encodeChildren(DefaultAjaxRenderer.java:73) at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:836) at mytest.jsf.util.ChildRendererUtil.renderChildren(ChildRendererUtil.java:47) at mytest.portal.ui.jsf.custom.component.htmltag.HtmlTagRenderer.encodeChildren(HtmlTagRenderer.java:110) at com.ibm.faces.renderkit.DefaultAjaxRenderer.encodeChildren(DefaultAjaxRenderer.java:73) at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:836) at mytest.jsf.util.ChildRendererUtil.renderChildren(ChildRendererUtil.java:47) at mytest.portal.ui.jsf.custom.component.htmltag.HtmlTagRenderer.encodeChildren(HtmlTagRenderer.java:110) at com.ibm.faces.renderkit.DefaultAjaxRenderer.encodeChildren(DefaultAjaxRenderer.java:73) at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:836) at mytest.jsf.util.ChildRendererUtil.renderChildren(ChildRendererUtil.java:47) at mytest.portal.ui.jsf.custom.component.htmltag.HtmlTagRenderer.encodeChildren(HtmlTagRenderer.java:110) at com.ibm.faces.renderkit.DefaultAjaxRenderer.encodeChildren(DefaultAjaxRenderer.java:73) at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:836) at javax.faces.component.UIComponent.encodeAll(UIComponent.java:936) at javax.faces.component.UIComponent.encodeAll(UIComponent.java:942) at javax.faces.render.Renderer.encodeChildren(Renderer.java:148) at com.ibm.faces.renderkit.DefaultAjaxRenderer.encodeChildren(DefaultAjaxRenderer.java:73) at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:836) at javax.faces.component.UIComponent.encodeAll(UIComponent.java:936) at javax.faces.component.UIComponent.encodeAll(UIComponent.java:942) at com.sun.faces.application.ViewHandlerImpl.doRenderView(ViewHandlerImpl.java:292) at com.sun.faces.application.ViewHandlerImpl.renderView(ViewHandlerImpl.java:223) at com.ibm.faces.portlet.PortletViewHandlerImpl.renderView(PortletViewHandlerImpl.java:79) at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:114) at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:100) at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139) at com.ibm.faces.portlet.FacesPortlet.doRender(FacesPortlet.java:372) ... 221 more Caused by: java.lang.NullPointerException at com.ibm.faces.portlet.httpbridge.PortletSessionWrapper.getAttributeNames(PortletSessionWrapper.java:185) at mytest.portal.testportlet.view.MyPortletViewBean.getProductId(MyPortletViewBean.java:394) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:60) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37) at java.lang.reflect.Method.invoke(Method.java:611) at javax.el.BeanELResolver.getValue(BeanELResolver.java:64) at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:143) at com.sun.faces.el.FacesCompositeELResolver.getValue(FacesCompositeELResolver.java:73) at org.apache.el.parser.AstValue.getValue(AstValue.java:102) at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:263) at org.apache.jasper.el.JspValueExpression.getValue(JspValueExpression.java:100) ... 265 more

使用以下代码获取会话范围：

FacesContext facesContext = getFacesContext(); if (facesContext != null) { return (PortletSession) facesContext.getExternalContext().getSession(createIfNotExist); } return null;

其中createIfNotExist false 。

Answer 1

听起来像jsf-portletbridge.jar PortletRequestWrapper类型中的缺陷。 JSF参考实现被写入servlet规范。请求包装器实现HttpServletRequest。 ExternalContext.getSession(boolean)会调用HttpServletRequest.getSession(boolean)。这将返回实现PortletSessionWrapper和HttpSession的装饰器对象PortletSession。听起来像请求装饰器返回会话装饰器，即使基础PortletSession为空。

我会尝试这种形式的代码：

    PortletRequest request = (PortletRequest) FacesContext.getCurrentInstance()
                                                          .getExternalContext()
                                                          .getRequest();
    PortletSession session = request.getPortletSession(false);
    if (session == null) {
        return null;
    }
    else {
        return session.getAttribute("foo", PortletSession.APPLICATION_SCOPE);
    }

IBM JSF PortletSession为null

1 个答案: