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(CoyoteRequestFacade .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(ApplicationFilterCh ain.java:193) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.ja va:256) at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invok eNext(StandardPipeline.java:643) at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480) at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.ja va:191) at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.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.java:2416) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:180 ) at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invok eNext(StandardPipeline.java:643) at org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve. java:171) at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invok eNext(StandardPipeline.java:641) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:172 ) at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invok eNext(StandardPipeline.java:641) at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480) at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java :174) at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.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.java:223) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:601) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConne ction(Http11Protocol.java:392) at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:565) at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.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]
