struts-2.3.1.2 web.xml中应该怎么配置
<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>
我是这么配置的 

启动tomcat报错

2012-4-26 20:54:29 org.apache.catalina.core.AprLifecycleListener init
信息: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: C:\Common\binary\com.sun.java.jdk.win32.x86_1.6.0.013\bin;D:\apache-tomcat-6.0.30\bin
2012-4-26 20:54:29 org.apache.coyote.http11.Http11Protocol init
信息: Initializing Coyote HTTP/1.1 on http-8080
2012-4-26 20:54:29 org.apache.catalina.startup.Catalina load
信息: Initialization processed in 645 ms
2012-4-26 20:54:29 org.apache.catalina.core.StandardService start
信息: Starting service Catalina
2012-4-26 20:54:29 org.apache.catalina.core.StandardEngine start
信息: Starting Servlet Engine: Apache Tomcat/6.0.30
2012-4-26 20:54:29 org.apache.catalina.startup.HostConfig deployDescriptor
信息: Deploying configuration descriptor host-manager.xml
2012-4-26 20:54:30 org.apache.catalina.startup.HostConfig deployDescriptor
信息: Deploying configuration descriptor manager.xml
2012-4-26 20:54:30 org.apache.catalina.startup.HostConfig deployDirectory
信息: Deploying web application directory docs
2012-4-26 20:54:30 org.apache.catalina.startup.HostConfig deployDirectory
信息: Deploying web application directory examples
2012-4-26 20:54:30 org.apache.catalina.core.ApplicationContext log
信息: ContextListener: contextInitialized()
2012-4-26 20:54:30 org.apache.catalina.core.ApplicationContext log
信息: SessionListener: contextInitialized()
2012-4-26 20:54:30 org.apache.catalina.startup.HostConfig deployDirectory
信息: Deploying web application directory ROOT
2012-4-26 20:54:30 org.apache.catalina.startup.HostConfig deployDirectory
信息: Deploying web application directory struts2
2012-4-26 20:54:31 com.opensymphony.xwork2.util.logging.commons.CommonsLogger info
信息: Parsing configuration file [struts-default.xml]
2012-4-26 20:54:31 com.opensymphony.xwork2.util.logging.commons.CommonsLogger info
信息: Unable to locate configuration files of the name struts-plugin.xml, skipping
2012-4-26 20:54:31 com.opensymphony.xwork2.util.logging.commons.CommonsLogger info
信息: Parsing configuration file [struts-plugin.xml]
2012-4-26 20:54:31 com.opensymphony.xwork2.util.logging.commons.CommonsLogger info
信息: Parsing configuration file [struts.xml]
2012-4-26 20:54:31 com.opensymphony.xwork2.util.logging.commons.CommonsLogger info
信息: Overriding property struts.i18n.reload - old value: false new value: true
2012-4-26 20:54:31 com.opensymphony.xwork2.util.logging.commons.CommonsLogger info
信息: Overriding property struts.configuration.xml.reload - old value: false new value: true
2012-4-26 20:54:32 org.apache.catalina.startup.HostConfig deployDirectory
信息: Deploying web application directory TestStruts2
2012-4-26 20:54:32 com.opensymphony.xwork2.util.logging.commons.CommonsLogger info
信息: Parsing configuration file [struts-default.xml]
2012-4-26 20:54:32 org.apache.catalina.core.StandardContext filterStart
严重: Exception starting filter struts2
java.lang.NoClassDefFoundError: org/apache/commons/lang/StringUtils
at 怎么将俩个十六字节拼接后转换成一个字符