在resin 3.0.9 及以前版本下，下面几种写法都是可以的，而放到Tomcat 5.0 下则抛出这个异常：
严重: Parse error in application web.xml
java.lang.IllegalArgumentException: Invalid <url-pattern> * in filter mapping
at org.apache.commons.digester.Digester.createSAXException(Digester.java:2540)
at org.apache.commons.digester.Digester.createSAXException(Digester.java:2566)
at org.apache.commons.digester.Digester.endElement(Digester.java:1061)
at org.apache.xerces.parsers.AbstractSAXParser.endElement(Unknown Source)
at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanEndElement(Unknown Source)
at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)
at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
at org.apache.commons.digester.Digester.parse(Digester.java:1548)
at org.apache.catalina.startup.ContextConfig.applicationConfig(ContextConfig.java:263)
at org.apache.catalina.startup.ContextConfig.start(ContextConfig.java:624)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:216)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4290)
at org.apache.catalina.core.StandardHostDeployer.start(StandardHostDeployer.java:830)
at org.apache.catalina.core.StandardHost.start(StandardHost.java:991)
at org.apache.catalina.manager.ManagerServlet.start(ManagerServlet.java:1322)
at org.apache.catalina.manager.HTMLManagerServlet.start(HTMLManagerServlet.java:530)
at org.apache.catalina.manager.HTMLManagerServlet.doGet(HTMLManagerServlet.java:104)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
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.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.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:540)
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.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)
必须写成这个：
<filter-mapping>
<filter-name>Set Character Encoding</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
写成这个不行：
<filter-mapping>
<filter-name>Set Character Encoding</filter-name>
<url-pattern>*</url-pattern>
</filter-mapping>
而我改成这样，却是正确的，通过了：
<filter-mapping>
<filter-name>Set Character Encoding</filter-name>
<url-pattern>*.action</url-pattern>
</filter-mapping>
因此，我认为这是个bug。