Question

我使用Mojarra 2.2.2，PrimeFaces 4.0，OmniFaces 1.7，Tomcat 7，Weld。

当会话在服务器上到期并且发送了ajax请求时，会出现以下堆栈跟踪：

java.lang.NullPointerException
at com.sun.faces.context.PartialViewContextImpl.createPartialResponseWriter(PartialViewContextImpl.java:485)
at com.sun.faces.context.PartialViewContextImpl.access$300(PartialViewContextImpl.java:73)
at com.sun.faces.context.PartialViewContextImpl$DelayedInitPartialResponseWriter.getWrapped(PartialViewContextImpl.java:619)
at javax.faces.context.PartialResponseWriter.startDocument(PartialResponseWriter.java:116)
at org.omnifaces.context.OmniPartialViewContext$OmniPartialResponseWriter.startDocument(OmniPartialViewContext.java:270)
at org.primefaces.context.PrimePartialResponseWriter.startDocument(PrimePartialResponseWriter.java:134)
at com.sun.faces.context.AjaxExceptionHandlerImpl.handlePartialResponseError(AjaxExceptionHandlerImpl.java:201)
at com.sun.faces.context.AjaxExceptionHandlerImpl.handle(AjaxExceptionHandlerImpl.java:126)
at javax.faces.context.ExceptionHandlerWrapper.handle(ExceptionHandlerWrapper.java:100)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:119)
at com.sun.faces.lifecycle.RestoreViewPhase.doPhase(RestoreViewPhase.java:121)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:198)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:646)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.meb.lotrlcg.web.core.TrackSessionFilter.doFilter(TrackSessionFilter.java:80)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
at java.lang.Thread.run(Thread.java:662)

为什么抛出NullPointerException而不是ViewExpiredException？我怎样才能以正确的方式处理这个问题？我在faces-config.xml中注册了一个异常处理程序，并在web-xml中添加了一个appriopriate错误页面。

Answer 1

Solved（有点......） - 似乎在web.xml中启用了部分状态保存（这是默认行为），并且按预期抛出了ViewExpiredException。

<context-param>
    <param-name>javax.faces.PARTIAL_STATE_SAVING</param-name>
    <param-value>true</param-value>
</context-param>

我仍然不知道它为什么会起作用。

Answer 2

刚刚遇到这个问题，并且能够在2.2.12使用相同的javax.faces.PARTIAL_STATE_SAVING = true来解决这个问题

打开https://java.net/jira/browse/JAVASERVERFACES-4193

JSF2 NullPointerException而不是ViewExpiredException

2 个答案: