Hi Andy, I was considering that also however the req and res objects are specified as private members of the overall class that has been created (extends filter obviously) and i would have assumed that each request would instatiate a new object.
Certainly willing to try them as local variables if you think that may help. cheers, Bradley >�Where are your req and res variables defined? They should be >�local to the doFilter() method or you could get concurrency >�issues. >� >�Andy >� >�-----Original Message----- >�From: Bradley Beddoes [mailto:[EMAIL PROTECTED] >�Sent: 28 October 2003 07:50 >�To: [EMAIL PROTECTED] >�Subject: Servlet.Service() NullPointer on Filter - Really need >�some help on this one... >� >� >�Hi All, >�I am hoping that someone is able to assist with some problems I >�am currently having with a filter I have written. The filter is >�designed to deal with authentication for users to check they have >�a particular cookie set then place an object into the session for >�further use. I have researched this error extensively online and >�can't find any documentation on correcting it. >� >�The error presented below only occurs on around 12% of requests >�(sometimes a few percent either side of this) according to my >�profiler when the code is put under some load - I am wondering if >�it may be caused by some form of concurrent request error in the >�filters whereby the Servlet object is being reset or otherwise >�nulled out. >� >�The codebase looks like: >�public void doFilter( ServletRequest request, ServletResponse >�response, FilterChain chain )throws IOException, ServletException >� { >� try >� { >� req = (HttpServletRequest)request; >� res = (HttpServletResponse)response; >� >� ...... >� >� //Create Session object >� HttpSession session = req.getSession( true ); >� session.setAttribute( QutClientObject.NAME, >�qutClient ); >� sessionCreated = true; >� >� //set REMOTE_USER >� >�res.addHeader("REMOTE_USER",qutClient.getUserName()); >� >� // Filter chaining completed, move to next filter >�in chain >� chain.doFilter( request, response ); >� >� return; >� } >� } >� >�Error occurs on line: req.getSession( true ); >� >�The error from tomcat(both 4.1.24 and 4.1.27) is: >� >�2003-10-28 17:35:35 StandardWrapperValve[jsp]: Servlet.service() >�for servlet jsp threw exception >�java.lang.NullPointerException >� at >�org.apache.coyote.tomcat4.CoyoteRequestFacade.getSession(CoyoteRe >�questFacade .java:365) >� at >�au.edu.qut.jauth.client.JAuthFilter.doFilter(JAuthFilter.java:197 >�) >� at >�org.apache.catalina.core.ApplicationFilterChain.internalDoFilter( >�Application FilterChain.java:213) >� at >�org.apache.catalina.core.ApplicationFilterChain.doFilter(Applicat >�ionFilterCh ain.java:193) >� at >�org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrap >�perValve.ja va:256) >� at >�org.apache.catalina.core.StandardPipeline$StandardPipelineValveCo >�ntext.invok eNext(StandardPipeline.java:643) >� at >�org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline >�.java:480) >� at >�org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java: >�995) >� at >�org.apache.catalina.core.StandardContextValve.invoke(StandardCont >�extValve.ja va:191) >� at >�org.apache.catalina.core.StandardPipeline$StandardPipelineValveCo >�ntext.invok eNext(StandardPipeline.java:643) >� at >�org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline >�.java:480) >� at >�org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java: >�995) >� at >�org.apache.catalina.core.StandardContext.invoke(StandardContext.j >�ava:2416) >� at >�org.apache.catalina.core.StandardHostValve.invoke(StandardHostVal >�ve.java:180 ) >� at >�org.apache.catalina.core.StandardPipeline$StandardPipelineValveCo >�ntext.invok eNext(StandardPipeline.java:643) >� at >�org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispa >�tcherValve. java:171) >� at >�org.apache.catalina.core.StandardPipeline$StandardPipelineValveCo >�ntext.invok eNext(StandardPipeline.java:641) >� at >�org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportVal >�ve.java:172 ) >� at >�org.apache.catalina.core.StandardPipeline$StandardPipelineValveCo >�ntext.invok eNext(StandardPipeline.java:641) >� at >�org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline >�.java:480) >� at >�org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java: >�995) >� at >�org.apache.catalina.core.StandardEngineValve.invoke(StandardEngin >�eValve.java :174) >� at >�org.apache.catalina.core.StandardPipeline$StandardPipelineValveCo >�ntext.invok eNext(StandardPipeline.java:643) >� at >�org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline >�.java:480) >� at >�org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java: >�995) >� at >�org.apache.coyote.tomcat4.CoyoteAdapter.service(CoyoteAdapter.jav >�a:223) >� at >�org.apache.coyote.http11.Http11Processor.process(Http11Processor. >�java:601) >� at >�org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.p >�rocessConne ction(Http11Protocol.java:392) >� at >�org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint. >�java:565) >� at >�org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(Thr >�eadPool.jav a:619) >� at java.lang.Thread.run(Thread.java:534) >� >� >�Any help would be very much appreciated I am almost out of ideas >�for this one... >� >�cheers, >�Bradley. >� >� >� >� >�----------------------------------------------------------------- >�---- To unsubscribe, e-mail: >[EMAIL PROTECTED] For additional >�commands, e-mail: [EMAIL PROTECTED] >� >�----------------------------------------------------------------- >�---- To unsubscribe, e-mail: >[EMAIL PROTECTED] For additional >�commands, e-mail: [EMAIL PROTECTED] >� --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
