我新搭起一个struts框架，环境配置好了进行测试，启动tomcat的时候出现了以下异常，google了下，好多高人说是配置问题，我检查了struts-config.xml文件，在能力范围之内没有发现问题，web.xml也一样，还请高人指点是不是配置造成的异常？
另外，java.lang.UnsupportedClassVersionError: Bad version number in .class file
这句话的意思怎么理解呢？？
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.apache.commons.beanutils.PropertyUtilsBean.invokeMethod(PropertyUtilsBean.java:2155)
at org.apache.commons.beanutils.PropertyUtilsBean.setSimpleProperty(PropertyUtilsBean.java:2141)
at org.apache.commons.beanutils.PropertyUtilsBean.setNestedProperty(PropertyUtilsBean.java:1948)
at org.apache.commons.beanutils.PropertyUtilsBean.setProperty(PropertyUtilsBean.java:2054)
at org.apache.commons.beanutils.BeanUtilsBean.setProperty(BeanUtilsBean.java:1015)
at org.apache.commons.beanutils.BeanUtilsBean.populate(BeanUtilsBean.java:830)
at org.apache.commons.beanutils.BeanUtils.populate(BeanUtils.java:433)
at org.apache.commons.digester.SetPropertiesRule.begin(SetPropertiesRule.java:252)
at org.apache.commons.digester.Rule.begin(Rule.java:175)
at org.apache.commons.digester.Digester.startElement(Digester.java:1453)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.startElement(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.AbstractXMLDocumentParser.emptyElement(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.dtd.XMLDTDValidator.emptyElement(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanStartElement(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(Unknown Source)
at org.apache.commons.digester.Digester.parse(Digester.java:1827)
at org.apache.struts.action.ActionServlet.parseModuleConfigFile(ActionServlet.java:740)
at org.apache.struts.action.ActionServlet.initModuleConfig(ActionServlet.java:689)
at org.apache.struts.action.ActionServlet.init(ActionServlet.java:356)
at javax.servlet.GenericServlet.init(GenericServlet.java:212)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1139)
at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:966)
at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:3956)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4230)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:760)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:740)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:544)
at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:626)
at org.apache.catalina.startup.HostConfig.deployDescriptors(HostConfig.java:553)
at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:488)
at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1150)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:311)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:120)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1022)