请教Struts2.0配置问题
web.xml

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

<filter>
  <filter-name>struts2</filter-name>
  <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
  </filter>
  <filter-mapping>
  <filter-name>struts2</filter-name>
  <url-pattern>/*</url-pattern>
  </filter-mapping>
   
  <welcome-file-list>
  <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>
------------------------------------------------------
struts.xml

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

<filter>
  <filter-name>struts2</filter-name>
  <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
  </filter>
  <filter-mapping>
  <filter-name>struts2</filter-name>
  <url-pattern>/*</url-pattern>
  </filter-mapping>
   
  <welcome-file-list>
  <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>

----------------------------------------------------

lib中有
commons-fileupload-1.2.2.jar
commons-logging-1.1.1.jar
freemarker-2.3.16.jar
ognl-3.0.1.jar
struts2-core-2.2.3.jar
xwork-core-2.2.3.jar

----------------------------------------------------
出错信息
警告: Could not create JarEntryRevision for [jar:file:/F:/Java/Tomcat%206.0/webapps/Struts/WEB-INF/lib/struts2-core-2.2.3.jar]!
java.lang.NoClassDefFoundError: org/apache/commons/io/FileUtils
at com.opensymphony.xwork2.util.FileManager$JarEntryRevision.build(FileManager.java:307)
at com.opensymphony.xwork2.util.FileManager.loadFile(FileManager.java:145)
at com.opensymphony.xwork2.util.FileManager.loadFile(FileManager.java:105)
at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadConfigurationFiles(XmlConfigurationProvider.java:898)
at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadDocuments(XmlConfigurationProvider.java:154)
at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.init(XmlConfigurationProvider.java:121)
at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:179)
at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:66)
at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:380)
at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:424)
at org.apache.struts2.dispatcher.ng.InitOperations.initDispatcher(InitOperations.java:69)
at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:51)
at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:295)
at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:422)