我正在对Tomcat 8.5.x中的一个问题进行疑难解答。 此问题仅影响一个部署（DEV服务器）；完全相同的源和配置可在其他地方完美运行。
这是示例堆栈跟踪（完整）：
ERROR [uP-PortletExec-199-pr015-RENDER-[portlet-admin]] o.s.web.portlet.DispatcherPortlet 2018-08-07 08:18:44,738 - Could not complete request
org.springframework.webflow.execution.FlowExecutionException: Exception thrown in state 'listChannels' of flow 'portlet-manager'
at org.springframework.webflow.engine.impl.FlowExecutionImpl.wrap(FlowExecutionImpl.java:573)
at org.springframework.webflow.engine.impl.FlowExecutionImpl.start(FlowExecutionImpl.java:227)
at org.springframework.webflow.executor.FlowExecutorImpl.launchExecution(FlowExecutorImpl.java:140)
at org.springframework.webflow.mvc.portlet.FlowHandlerAdapter.startFlowRender(FlowHandlerAdapter.java:272)
at org.springframework.webflow.mvc.portlet.FlowHandlerAdapter.handleRender(FlowHandlerAdapter.java:134)
at org.springframework.web.portlet.DispatcherPortlet.doRenderService(DispatcherPortlet.java:764)
at org.springframework.web.portlet.FrameworkPortlet.processRequest(FrameworkPortlet.java:537)
at org.springframework.web.portlet.FrameworkPortlet.doDispatch(FrameworkPortlet.java:483)
at javax.portlet.GenericPortlet.render(GenericPortlet.java:251)
at org.apereo.portal.portlet.container.FilterChainImpl.doFilter(FilterChainImpl.java:179)
at org.apereo.portal.portlet.container.FilterChainImpl.processFilter(FilterChainImpl.java:95)
at org.apereo.portal.portlet.container.FilterManagerImpl.processFilter(FilterManagerImpl.java:114)
at org.apache.pluto.container.driver.PortletServlet.dispatch(PortletServlet.java:340)
at org.apache.pluto.container.driver.PortletServlet.doGet(PortletServlet.java:261)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:728)
at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:591)
at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:527)
at org.apache.pluto.driver.container.DefaultPortletInvokerService.invoke(DefaultPortletInvokerService.java:233)
at org.apache.pluto.driver.container.DefaultPortletInvokerService.render(DefaultPortletInvokerService.java:117)
at sun.reflect.GeneratedMethodAccessor283.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:333)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:85)
at org.apereo.portal.portlet.dao.jpa.ThreadContextClassLoaderAspect.doThreadContextClassLoaderUpdate(ThreadContextClassLoaderAspect.java:63)
at sun.reflect.GeneratedMethodAccessor181.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:629)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:618)
at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:70)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213)
at com.sun.proxy.$Proxy356.render(Unknown Source)
at org.apache.pluto.container.impl.PortletContainerImpl.doRender(PortletContainerImpl.java:157)
at org.apereo.portal.portlet.rendering.PortletRendererImpl.doRender(PortletRendererImpl.java:456)
at org.apereo.portal.portlet.rendering.PortletRendererImpl.doRenderMarkup(PortletRendererImpl.java:275)
at org.apereo.portal.portlet.rendering.worker.PortletRenderExecutionWorker.callInternal(PortletRenderExecutionWorker.java:69)
at org.apereo.portal.portlet.rendering.worker.PortletRenderExecutionWorker.callInternal(PortletRenderExecutionWorker.java:33)
at org.apereo.portal.portlet.rendering.worker.PortletExecutionWorker$1.call(PortletExecutionWorker.java:185)
at org.apereo.portal.portlet.rendering.worker.PortletExecutionWorker$ExecutionLifecycleCallable.call(PortletExecutionWorker.java:225)
at org.apereo.portal.portlet.rendering.worker.PortletExecutionCallable.call(PortletExecutionCallable.java:113)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.IllegalStateException: Exception occurred rendering view org.springframework.web.servlet.view.JstlView: unnamed; URL [/WEB-INF/flows/portlet-mana
ger/listChannels.jsp]
at org.springframework.webflow.mvc.view.AbstractMvcView.render(AbstractMvcView.java:208)
at org.springframework.webflow.engine.ViewState.render(ViewState.java:293)
at org.springframework.webflow.engine.ViewState.doEnter(ViewState.java:185)
at org.springframework.webflow.engine.State.enter(State.java:194)
at org.springframework.webflow.engine.Flow.start(Flow.java:527)
at org.springframework.webflow.engine.impl.FlowExecutionImpl.start(FlowExecutionImpl.java:368)
at org.springframework.webflow.engine.impl.FlowExecutionImpl.start(FlowExecutionImpl.java:223)
... 52 common frames omitted
Caused by: javax.portlet.PortletException: javax.servlet.ServletException: File [/WEB-INF/flows/portlet-manager/listChannels.jsp] not found
at org.apache.pluto.container.impl.PortletRequestDispatcherImpl.doDispatch(PortletRequestDispatcherImpl.java:187)
at org.apache.pluto.container.impl.PortletRequestDispatcherImpl.include(PortletRequestDispatcherImpl.java:222)
at org.springframework.webflow.mvc.portlet.PortletMvcView.doRender(PortletMvcView.java:67)
at org.springframework.webflow.mvc.view.AbstractMvcView.render(AbstractMvcView.java:204)
... 58 common frames omitted
Caused by: javax.servlet.ServletException: File [/WEB-INF/flows/portlet-manager/listChannels.jsp] not found
at org.apache.jasper.servlet.JspServlet.handleMissingResource(JspServlet.java:408)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:388)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:330)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:728)
at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:591)
at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:527)
at org.apache.pluto.container.impl.PortletRequestDispatcherImpl.include(PortletRequestDispatcherImpl.java:268)
at org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:160)
at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:303)
at org.springframework.web.servlet.ViewRendererServlet.renderView(ViewRendererServlet.java:114)
at org.springframework.web.servlet.ViewRendererServlet.processRequest(ViewRendererServlet.java:86)
at org.springframework.web.servlet.ViewRendererServlet.doGet(ViewRendererServlet.java:66)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:728)
at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:591)
at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:527)
at org.apache.pluto.container.impl.PortletRequestDispatcherImpl.doDispatch(PortletRequestDispatcherImpl.java:174)
... 61 common frames omitted
一些其他要点：
/WEB-INF/flows/portlet-manager/listChannels.jsp-正确存在该文件的位置100％。有人见过类似这个问题吗？谁能想到其他要检查的东西？
答案 0 :(得分：1)
可能是文件所有权问题。试试：
找到[tomcat_home]-！ -user [expected_owner] -ls
应显示[expected_owner]不拥有的所有文件。
如果找到了一些不属于用户的文件，请尝试：
sudo chown -R [expected_owner]：[expected_group] [tomcat_home]
答案 1 :(得分：1)
我认为我们应该关注此消息
Caused by: javax.servlet.ServletException: File [/WEB-INF/flows/portlet-manager/listChannels.jsp] not found
为什么文件具有前缀/WEB-INF/flows/portlet-manager/
我猜这是因为您返回的是这样的空字符串：
return ""