为什么web.xml错误
<?xml version= "1.0 " encoding= "UTF-8 "?>
<web-app xmlns= "http://java.sun.com/xml/ns/j2ee " xmlns:xsi= "http://www.w3.org/2001/XMLSchema-instance " version= "2.4 " xsi:schemaLocation= "http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd ">

<!-- Standard Action Servlet Configuraction -->
<servlet>
<servlet-name> action </servlet-name>
<servlet-class> org.apache.struts.action.ActionServlet </servlet-class>

<init-param>
<param-name> config </param-name>
<param-value> /WEB-INF/struts-config.xml </param-value>
</init-param>
<load-on-startup> 2 </load-on-startup>
</servlet>

<!-- Standard Action Servlet Mapping -->
<servlet-mapping>
<servlet-name> action </servlet-name>
<url-pattern> *.do </url-pattern>
</servlet-mapping>

<!-- The Usual Welcome File List -->
<welcome-file-list>
<welcome-file> hello.jsp </welcome-file>
</welcome-file-list>

<!-- Struts Tag Library Descriptors -->
<taglib>
<taglib-url> /WEB-INF/tld/struts-bean.tld </taglib-url>
<taglib-location> /WEB-INF/struts-bean.tld </taglib-location>
</taglib>

<taglib>
<taglib-url> /WEB-INF/tld/struts-html.tld </taglib-url>
<taglib-location> /WEB-INF/struts-html.tld </taglib-location>
</taglib>

<taglib>
<taglib-url> /WEB-INF/tld/struts-logic.tld </taglib-url>
<taglib-location> /WEB-INF/struts-logic.tld </taglib-location>
</taglib>
</web-app>


提示这里错误
<taglib>
<taglib-url> /WEB-INF/tld/struts-bean.tld </taglib-url>
<taglib-location> /WEB-INF/struts-bean.tld </taglib-location>
</taglib>


java.lang.IllegalArgumentException: Can 't convert argument: null
at org.apache.tomcat.util.IntrospectionUtils.convert(IntrospectionUtils.java:975)
at org.apache.tomcat.util.digester.CallMethodRule.end(CallMethodRule.java:522)
at org.apache.tomcat.util.digester.Rule.end(Rule.java:228)
at org.apache.tomcat.util.digester.Digester.endElement(Digester.java:1057)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.endElement(AbstractSAXParser.java:633)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanEndElement(XMLDocumentFragmentScannerImpl.java:1241)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(XMLDocumentFragmentScannerImpl.java:1685)

at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:368)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:834)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:764)
at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:148)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1242)
at org.apache.tomcat.util.digester.Digester.parse(Digester.java:1561)
at org.apache.catalina.startup.ContextConfig.applicationWebConfig(ContextConfig.java:351)
at org.apache.catalina.startup.ContextConfig.start(ContextConfig.java:1041)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:260)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4143)
at org.apache.catalina.startup.HostConfig.checkResources(HostConfig.java:1089)
at org.apache.catalina.startup.HostConfig.check(HostConfig.java:1187)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:292)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
at org.apache.catalina.core.ContainerBase.backgroundProcess(ContainerBase.java:1305)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1569)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1578)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.run(ContainerBase.java:1558)
at java.lang.Thread.run(Thread.java:595)
2007-3-15 15:31:22 org.apache.catalina.startup.ContextConfig applicationWebConfig
严重: Parse error in application web.xml file at jndi:/localhost/lcWeb/WEB-INF/web.xml
java.lang.IllegalArgumentException: Can 't convert argument: null
at org.apache.tomcat.util.digester.Digester.createSAXException(Digester.java:2725)
at org.apache.tomcat.util.digester.Digester.createSAXException(Digester.java:2751)
at org.apache.tomcat.util.digester.Digester.endElement(Digester.java:1060)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.endElement(AbstractSAXParser.java:633)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanEndElement(XMLDocumentFragmentScannerImpl.java:1241)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(XMLDocumentFragmentScannerImpl.java:1685)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:368)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:834)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:764)
at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:148)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1242)
at org.apache.tomcat.util.digester.Digester.parse(Digester.java:1561)
at org.apache.catalina.startup.ContextConfig.applicationWebConfig(ContextConfig.java:351)
at org.apache.catalina.startup.ContextConfig.start(ContextConfig.java:1041)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:260)

at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4143)
at org.apache.catalina.startup.HostConfig.checkResources(HostConfig.java:1089)
at org.apache.catalina.startup.HostConfig.check(HostConfig.java:1187)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:292)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
at org.apache.catalina.core.ContainerBase.backgroundProcess(ContainerBase.java:1305)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1569)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1578)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.run(ContainerBase.java:1558)
at java.lang.Thread.run(Thread.java:595)
2007-3-15 15:31:22 org.apache.catalina.startup.ContextConfig applicationWebConfig
严重: Occurred at line 31 column 13
2007-3-15 15:31:22 org.apache.catalina.startup.ContextConfig start
严重: Marking this application unavailable due to previous error(s)
2007-3-15 15:31:22 org.apache.catalina.core.StandardContext start
严重: Error getConfigured
2007-3-15 15:31:22 org.apache.catalina.core.StandardContext start
严重: Context [/lcWeb] startup failed due to previous errors

[解决办法]
刚才打错了，是 <taglib-uri> 不是 <taglib-url>
<jsp-config>
<taglib>
<taglib-uri> /WEB-INF/tld/struts-bean.tld </taglib-url>
<taglib-location> /WEB-INF/struts-bean.tld </taglib-location>
</taglib>
<taglib>
..................
</taglib>
</jsp-config>