When using Synchronous mode, if the session expires any attempt to interact with components in the browsers returns either:

  - A big nasty NPE exception in the browser (FF)
  - A blank page (IE)

The only way to recover is to either open a new viewport to the app. URL or use the browser Back button to return to the app. URL.


Tomcat log:

Jun 29, 2007 10:27:46 AM com.icesoft.faces.webapp.http.servlet.MainSessionBoundServlet$2 run
WARNING: [1] views have accumulated updates

Firefox Error:

HTTP Status 500 -

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

java.lang.NullPointerException
com.icesoft.faces.webapp.http.servlet.ViewBoundAdaptingServlet.service(ViewBoundAdaptingServlet.java:39)
com.icesoft.faces.webapp.http.servlet.PathDispatcher$Matcher.serviceOnMatch(PathDispatcher.java:52)
com.icesoft.faces.webapp.http.servlet.PathDispatcher.service(PathDispatcher.java:29)
com.icesoft.faces.webapp.http.servlet.MainSessionBoundServlet.service(MainSessionBoundServlet.java:97)
com.icesoft.faces.webapp.http.servlet.SessionDispatcher.service(SessionDispatcher.java:35)
com.icesoft.faces.webapp.http.servlet.PathDispatcher$Matcher.serviceOnMatch(PathDispatcher.java:52)
com.icesoft.faces.webapp.http.servlet.PathDispatcher.service(PathDispatcher.java:29)
com.icesoft.faces.webapp.http.servlet.MainServlet.service(MainServlet.java:85)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
com.icesoft.faces.webapp.xmlhttp.BlockingServlet.service(BlockingServlet.java:54)

note The full stack trace of the root cause is available in the Apache Tomcat/5.0.28 logs.

Error in the tomcat logs:

2007-06-29 10:27:52 ApplicationDispatcher[/address] Servlet.service() for servlet Persistent Faces Servlet threw exception
java.lang.NullPointerException
    at com.icesoft.faces.webapp.http.servlet.ViewBoundAdaptingServlet.service(ViewBoundAdaptingServlet.java:39)
    at com.icesoft.faces.webapp.http.servlet.PathDispatcher$Matcher.serviceOnMatch(PathDispatcher.java:52)
    at com.icesoft.faces.webapp.http.servlet.PathDispatcher.service(PathDispatcher.java:29)
    at com.icesoft.faces.webapp.http.servlet.MainSessionBoundServlet.service(MainSessionBoundServlet.java:97)
    at com.icesoft.faces.webapp.http.servlet.SessionDispatcher.service(SessionDispatcher.java:35)
    at com.icesoft.faces.webapp.http.servlet.PathDispatcher$Matcher.serviceOnMatch(PathDispatcher.java:52)
    at com.icesoft.faces.webapp.http.servlet.PathDispatcher.service(PathDispatcher.java:29)
    at com.icesoft.faces.webapp.http.servlet.MainServlet.service(MainServlet.java:85)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:237)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
    at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:704)
    at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:474)
    at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:370)
    at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:312)
    at com.icesoft.faces.webapp.xmlhttp.BlockingServlet.service(BlockingServlet.java:54)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:237)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:214)
    at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
    at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:198)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:152)
    at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:137)
    at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:118)
    at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
    at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:929)
    at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:160)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:799)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:705)
    at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:577)
    at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:683)
    at java.lang.Thread.run(Thread.java:595)


This is affecting the ICEfaces.org site also.

The application should have a way to respond to the session expiry and pro-actively clean-up or close the connection, thus preventing the NPE and difficult to recover from error condition.