启动服务器报错，求解决

2012-10-21 14:41:14 org.apache.catalina.core.StandardContext filterStart
严重: Exception starting filter struts2
Unable to load configuration. - bean - jar:file:/E:/apache-tomcat-6.0.18/webapps/gwap3/WEB-INF/lib/struts2-core-2.2.1.jar!/struts-default.xml:29:72
 at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:58)
 at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:360)
 at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:403)
 at org.apache.struts2.dispatcher.FilterDispatcher.init(FilterDispatcher.java:190)
 at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:275)
 at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:397)
 at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:108)
 at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:3709)
 at org.apache.catalina.core.StandardContext.start(StandardContext.java:4363)
 at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:791)
 at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:771)
 at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:525)
 at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:926)
 at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:889)
 at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:492)
 at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1149)
 at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:311)
 at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
 at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1053)
 at org.apache.catalina.core.StandardHost.start(StandardHost.java:719)
 at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
 at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443)
 at org.apache.catalina.core.StandardService.start(StandardService.java:516)
 at org.apache.catalina.core.StandardServer.start(StandardServer.java:710)
 at org.apache.catalina.startup.Catalina.start(Catalina.java:578)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
 at java.lang.reflect.Method.invoke(Method.java:597)
 at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:288)
 at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:413)
Caused by: Unable to load bean: type: class:com.opensymphony.xwork2.ObjectFactory - bean - jar:file:/E:/apache-tomcat-6.0.18/webapps/gwap3/WEB-INF/lib/struts2-core-2.2.1.jar!/struts-default.xml:29:72
 at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.register(XmlConfigurationProvider.java:222)
 at org.apache.struts2.config.StrutsXmlConfigurationProvider.register(StrutsXmlConfigurationProvider.java:101)
 at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:165)
 at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:55)
 ... 30 more
Caused by: Bean type class com.opensymphony.xwork2.ObjectFactory with the name xwork has already been loaded by bean - jar:file:/E:/apache-tomcat-6.0.18/webapps/gwap3/WEB-INF/lib/struts2-core-2.1.6.jar!/struts-default.xml:29:72 - bean - jar:file:/E:/apache-tomcat-6.0.18/webapps/gwap3/WEB-INF/lib/struts2-core-2.2.1.jar!/struts-default.xml:29:72
 at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.register(XmlConfigurationProvider.java:206)
 ... 33 more
2012-10-21 14:41:14 org.apache.catalina.core.StandardContext start
严重: Error filterStart
2012-10-21 14:41:14 org.apache.catalina.core.StandardContext start
严重: Context [/gwap3] startup failed due to previous errors