[OS-webwork] RE: Problem chaining

[Les Stroud]

OK, well I figured it out and apparently I have been staring at this screen a little too long. J    I turned on jpda in tomcat and debugged through FilterDispatcher and discovered that the code in there would almost always disregard all of my results (except input) if the class was not ServletDispatcher (BTW, this is the part that confuses me since these errors happen at deploy time, not when I execute the action).  This struck me as a little odd.  So, I traced it a little further and found that, in this case, if you did not have an input result that you would always get a NullPointerEx.  In FilterDispatcher, around line 130, the success result is ignored and the input result is queried.  If there is no input result then line 195 will give a NPE.  Now, I haven’t spent the time to determine why I should have never gotten in this section of the code (though I would love to know the function of FilterDispatcher if someone can explain it in less time than it would take me to read J).  So, I stuck an input result in my action and the problem was solved.  Now, I will likely need this result at some point.  However, I’m not sure it’s presence should be a requirement.  Anyway, someone may want to look at this section and at least trap this NPE and provide a slightly more meaningful message (like please include an input result J ) or whether they should check for null of the resultConfig.   Thanx, LES   www.mindmeld.ws [EMAIL PROTECTED]     -----Original Message----- From: Les Stroud [mailto:[EMAIL PROTECTED] Sent: Sunday, June 08, 2003 10:37 PM To: '[EMAIL PROTECTED]' Cc: '[EMAIL PROTECTED]'; '[EMAIL PROTECTED]' Subject: Problem chaining   I’ve run into a problem when trying to chain from one action to another.  Whenever I try to load the following configuration, I get a NullPointerException in the FilterDispatcher(195).  However, when I run the same configuration via unit tests (using ActionProxy) it works fine – chaining the actions correctly.  The stack trace is below the xwork.xml. Can any body help?? <!-- ======================  xwork.xml =================================--> <!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork 1.0//EN" "http://www.opensymphony.com/xwork/xwork-1.0.dtd"> <xwork>        <package name="default">               <result-types>                      <result-type name="dispatcher" class="com.opensymphony.webwork.dispatcher.ServletDispatcherResult"/>                      <result-type name="redirect" class="com.opensymphony.webwork.dispatcher.ServletRedirectResult"/>                      <result-type name="velocity" class="com.opensymphony.webwork.dispatcher.VelocityResult"/>                      <result-type name="chain" class="com.opensymphony.xwork.ActionChainResult"/>               </result-types>               <interceptors>                      <interceptor name="timer" class="com.opensymphony.xwork.interceptor.TimerInterceptor"/>                      <interceptor name="logger" class="com.opensymphony.xwork.interceptor.LoggingInterceptor"/>                      <interceptor name="chain" class="com.opensymphony.xwork.interceptor.ChainingInterceptor"/>                      <interceptor name="static-params" class="com.opensymphony.xwork.interceptor.StaticParametersInterceptor"/>                      <interceptor name="params" class="com.opensymphony.xwork.interceptor.ParametersInterceptor"/>                      <interceptor name="validator" class="com.opensymphony.xwork.validator.ValidationInterceptor"/>                      <interceptor name="component" class="com.opensymphony.xwork.interceptor.component.ComponentInterceptor"/>                      <interceptor name="token" class="com.opensymphony.webwork.interceptor.TokenInterceptor"/>                      <interceptor name="token-session" class="com.opensymphony.webwork.interceptor.TokenSessionStoreInterceptor"/>                      <interceptor-stack name="defaultStack">                            <interceptor-ref name="timer"/>                            <interceptor-ref name="logger"/>                            <interceptor-ref name="component"/>                            <!--                <interceptor-ref name="static-params"/>-->                            <interceptor-ref name="params"/>                            <interceptor-ref name="validator"/>                      </interceptor-stack>               </interceptors>               <action name="ListAllPeople" class="com.les.mydirector.actions.teammanagement.ListAllPeopleAction">                      <result name="success" type="dispatcher">                            <param name="location">teammanagement/listAllPeople.jsp</param>                      </result>                      <interceptor-ref name="defaultStack"/>               </action>                             <action name="AddPerson" class="com.les.mydirector.actions.teammanagement.AddPersonAction">                      <result name="success" type="chain">                            <param name="actionName">ListAllPeople</param>                      </result>                      <interceptor-ref name="defaultStack"/>               </action>        </package> </xwork>   <!-- ============================ Stack Trace ======================================== -->   2003-06-08 22:10:28 StandardContext[/myapp]: Exception starting filter webwork java.lang.NullPointerException                 at com.opensymphony.webwork.dispatcher.FilterDispatcher.getActionResultConfig(FilterDispatcher.java:195)                 at com.opensymphony.webwork.dispatcher.FilterDispatcher.init(FilterDispatcher.java:132)                 at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:266)                 at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:327)                 at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:120)                 at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:3158)                 at org.apache.catalina.core.StandardContext.start(StandardContext.java:3602)                 at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:821)                 at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:807)                 at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:579)                 at org.apache.catalina.core.StandardHostDeployer.install(StandardHostDeployer.java:307)                 at org.apache.catalina.core.StandardHost.install(StandardHost.java:772)                 at org.apache.catalina.servlets.ManagerServlet.deploy(ManagerServlet.java:564)                 at org.apache.catalina.servlets.ManagerServlet.doPut(ManagerServlet.java:413)                 at javax.servlet.http.HttpServlet.service(HttpServlet.java:763)                 at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)                 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)                 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)                 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:256)                 at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)                 at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)                 at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)                 at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)                 at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)                 at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:551)                 at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)                 at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)                 at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)                 at org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2415)                 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:180)                 at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)                 at org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:171)                 at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)                 at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:172)                 at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(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$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)                 at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)                 at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)                 at org.apache.coyote.tomcat4.CoyoteAdapter.service(CoyoteAdapter.java:223)                 at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:594)                 at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:392)                 at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:565)                 at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:619)                 at java.lang.Thread.run(Thread.java:536)