Ich verwende Struts 2.3.16 zusammen mit derselben Version des Convention Plugins. Die Anwendung läuft unter Tomcat 7.0.35 einwandfrei, schlägt jedoch mit der folgenden Ausnahme unter Tomcat 8.0.3.0 fehl.

11-May-2014 06:26:01.421 WARNING [http-nio-8084-exec-5] com.opensymphony.xwork2.util.finder.UrlSet.warn Cannot translate url to external form!
 java.lang.NullPointerException
    at com.opensymphony.xwork2.util.finder.UrlSet.load(UrlSet.java:93)
    at com.opensymphony.xwork2.util.finder.UrlSet.<init>(UrlSet.java:83)
    at org.apache.struts2.convention.PackageBasedActionConfigBuilder.buildUrlSet(PackageBasedActionConfigBuilder.java:415)
    at org.apache.struts2.convention.PackageBasedActionConfigBuilder.readUrls(PackageBasedActionConfigBuilder.java:410)
    at org.apache.struts2.convention.PackageBasedActionConfigBuilder.findActions(PackageBasedActionConfigBuilder.java:389)
    at org.apache.struts2.convention.PackageBasedActionConfigBuilder.buildActionConfigs(PackageBasedActionConfigBuilder.java:347)
    at org.apache.struts2.convention.ClasspathPackageProvider.loadPackages(ClasspathPackageProvider.java:53)
    at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:268)
    at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:67)
    at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:445)
    at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:489)
    at org.apache.struts2.dispatcher.ng.InitOperations.initDispatcher(InitOperations.java:74)
    at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:57)
    at org.apache.catalina.core.ApplicationFilterConfig.initFilter(ApplicationFilterConfig.java:279)
    at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:260)
    at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:105)
    at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4574)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5184)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:726)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:702)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:697)
    at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:579)
    at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:455)
    at org.apache.catalina.startup.HostConfig.check(HostConfig.java:1554)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:300)
    at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
    at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:791)
    at org.apache.catalina.manager.ManagerServlet.check(ManagerServlet.java:1428)
    at org.apache.catalina.manager.ManagerServlet.deploy(ManagerServlet.java:885)
    at org.apache.catalina.manager.ManagerServlet.doGet(ManagerServlet.java:343)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:618)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:301)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.filters.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:108)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:615)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:136)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:74)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:516)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1015)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:652)
    at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:222)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1575)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1533)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
    at java.lang.Thread.run(Thread.java:722)

11-May-2014 06:26:01.453 SEVERE [http-nio-8084-exec-5] org.apache.struts2.convention.PackageBasedActionConfigBuilder.error Unable to scan named packages
 java.lang.NullPointerException
    at com.opensymphony.xwork2.util.finder.UrlSet.includeClassesUrl(UrlSet.java:193)
    at org.apache.struts2.convention.PackageBasedActionConfigBuilder.buildUrlSet(PackageBasedActionConfigBuilder.java:442)
    at org.apache.struts2.convention.PackageBasedActionConfigBuilder.readUrls(PackageBasedActionConfigBuilder.java:410)
    at org.apache.struts2.convention.PackageBasedActionConfigBuilder.findActions(PackageBasedActionConfigBuilder.java:389)
    at org.apache.struts2.convention.PackageBasedActionConfigBuilder.buildActionConfigs(PackageBasedActionConfigBuilder.java:347)
    at org.apache.struts2.convention.ClasspathPackageProvider.loadPackages(ClasspathPackageProvider.java:53)
    at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:268)
    at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:67)
    at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:445)
    at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:489)
    at org.apache.struts2.dispatcher.ng.InitOperations.initDispatcher(InitOperations.java:74)
    at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:57)
    at org.apache.catalina.core.ApplicationFilterConfig.initFilter(ApplicationFilterConfig.java:279)
    at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:260)
    at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:105)
    at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4574)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5184)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:726)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:702)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:697)
    at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:579)
    at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:455)
    at org.apache.catalina.startup.HostConfig.check(HostConfig.java:1554)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:300)
    at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
    at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:791)
    at org.apache.catalina.manager.ManagerServlet.check(ManagerServlet.java:1428)
    at org.apache.catalina.manager.ManagerServlet.deploy(ManagerServlet.java:885)
    at org.apache.catalina.manager.ManagerServlet.doGet(ManagerServlet.java:343)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:618)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:301)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.filters.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:108)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:615)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:136)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:74)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:516)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1015)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:652)
    at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:222)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1575)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1533)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
    at java.lang.Thread.run(Thread.java:722)

Aktionen in zugehörigen Aktionsklassen werden in langen Linien abgebildet.

@InputConfig(methodName="input")
@Action(value = "State",
        results = {
            @Result(name=ActionSupport.SUCCESS, location="State.jsp"),
            @Result(name = ActionSupport.INPUT, location = "State.jsp")},
        interceptorRefs={@InterceptorRef(value="ParamsPrepareParamsStack", params={"params.acceptParamNames", "id, currentPage, rowCount, totalPages", "validation.validateAnnotatedMethodOnly", "true", "validation.excludeMethods", "load"})})
public String load() throws Exception {
    return ActionSupport.SUCCESS;
}

Webseiten werden unter gespeichert/WEB-INF/content und Konfigurationsdateien wiestruts.properties sind gespeichert unter/WEB-INF/classes.

Sind einige neue Änderungen erforderlich, damit Tomcat 8.x ordnungsgemäß funktioniert?