p:accordionPanel 生成 java.lang.NullPointerException

p:accordionPanel generates java.lang.NullPointerException

我正在尝试 运行 这个简单的页面:

<?xml version='1.0' encoding='UTF-8' ?>  
<html xmlns="http://www.w3.org/1999/xhtml"
  xmlns:h="http://java.sun.com/jsf/html"
  xmlns:f="http://java.sun.com/jsf/core"
  xmlns:ui="http://java.sun.com/jsf/facelets"
  xmlns:p="http://primefaces.org/ui">
  
 <ui:composition template="/template/template.xhtml">
  <ui:define name="content">
   <h2 class="title">Últimas Notícias</h2>
   <h:form>
    <p:accordionPanel value="#{noticia.feed}" var="varNot" dynamic="true" rendered="#{noticia.feed.isEmpty() == false}" activeIndex="-2" name="mainpanel" id="mainPanel">
     <p:tab>
      <h:outputText value="#{varNot.noticia}" />
     </p:tab>
    </p:accordionPanel>
   </h:form>
  </ui:define>
 </ui:composition>
</html>

其中 noticia.feed 是对象列表 Noticia。

当我尝试运行这个页面时,遇到以下错误:

java.lang.NullPointerException
 at org.apache.catalina.connector.CoyoteWriter.write(CoyoteWriter.java:249)
 at com.sun.faces.application.view.WriteBehindStateWriter.write(WriteBehindStateWriter.java:127)
 at com.sun.faces.renderkit.html_basic.HtmlResponseWriter.write(HtmlResponseWriter.java:722)
 at org.primefaces.component.accordionpanel.AccordionPanelRenderer.encodeTab(AccordionPanelRenderer.java:201)
 at org.primefaces.component.accordionpanel.AccordionPanelRenderer.encodeTabs(AccordionPanelRenderer.java:170)
 at org.primefaces.component.accordionpanel.AccordionPanelRenderer.encodeMarkup(AccordionPanelRenderer.java:103)
 at org.primefaces.component.accordionpanel.AccordionPanelRenderer.encodeEnd(AccordionPanelRenderer.java:76)
 at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:919)
 at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1863)
 at javax.faces.render.Renderer.encodeChildren(Renderer.java:176)
 at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:889)
 at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1856)
 at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
 at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
 at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:456)
 at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:133)
 at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120)
 at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
 at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:219)
 at javax.faces.webapp.FacesServlet.service(FacesServlet.java:647)
 at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:344)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
 at filters.controleDeAcesso.doFilter(controleDeAcesso.java:86)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
 at filters.controleDeAcesso.doFilter(controleDeAcesso.java:86)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:316)
 at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
 at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
 at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
 at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
 at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:415)
 at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:282)
 at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
 at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
 at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:201)
 at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:175)
 at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
 at org.glassfish.grizzly.filterchain.ExecutorResolver.execute(ExecutorResolver.java:119)
 at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:284)
 at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:201)
 at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:133)
 at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:112)
 at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
 at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:561)
 at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
 at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
 at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access0(WorkerThreadIOStrategy.java:56)
 at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
 at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:565)
 at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:545)
 at java.lang.Thread.run(Thread.java:745)

而且我根本无法理解为什么,因为我 运行 在另一个应用程序中使用了相同的代码。

我运行使用 PrimeFaces 5.1 和 Glassfish 4.1 对其进行调试。

有人知道吗?

此外,在控制台日志中,抛出以下消息:

FATAL: JSF1073: java.lang.NullPointerException obtido durante o processamento de RENDER_RESPONSE 6: UIComponent-ClientId=, Message=null
FATAL: No associated message
java.lang.NullPointerException
 at org.apache.catalina.connector.CoyoteWriter.write(CoyoteWriter.java:249)
 at com.sun.faces.application.view.WriteBehindStateWriter.write(WriteBehindStateWriter.java:127)
 at com.sun.faces.renderkit.html_basic.HtmlResponseWriter.write(HtmlResponseWriter.java:722)
 at org.primefaces.component.accordionpanel.AccordionPanelRenderer.encodeTab(AccordionPanelRenderer.java:201)
 at org.primefaces.component.accordionpanel.AccordionPanelRenderer.encodeTabs(AccordionPanelRenderer.java:170)
 at org.primefaces.component.accordionpanel.AccordionPanelRenderer.encodeMarkup(AccordionPanelRenderer.java:103)
 at org.primefaces.component.accordionpanel.AccordionPanelRenderer.encodeEnd(AccordionPanelRenderer.java:76)
 at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:919)
 at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1863)
 at javax.faces.render.Renderer.encodeChildren(Renderer.java:176)
 at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:889)
 at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1856)
 at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
 at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
 at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:456)
 at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:133)
 at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120)
 at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
 at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:219)
 at javax.faces.webapp.FacesServlet.service(FacesServlet.java:647)
 at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:344)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
 at filters.controleDeAcesso.doFilter(controleDeAcesso.java:86)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
 at filters.controleDeAcesso.doFilter(controleDeAcesso.java:86)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:316)
 at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
 at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
 at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
 at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
 at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:415)
 at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:282)
 at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
 at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
 at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:201)
 at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:175)
 at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
 at org.glassfish.grizzly.filterchain.ExecutorResolver.execute(ExecutorResolver.java:119)
 at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:284)
 at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:201)
 at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:133)
 at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:112)
 at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
 at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:561)
 at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
 at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
 at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access0(WorkerThreadIOStrategy.java:56)
 at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
 at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:565)
 at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:545)
 at java.lang.Thread.run(Thread.java:745)

p:tab 组件中缺少标题属性

<p:tab title="someTitle">
    <h:outputText value="#{varNot.noticia}" />
</p:tab>