我已经使用 eclipse 在我的本地机器上编写了几个 servlet。我已经在我的本地机器上对它们进行了测试，一切正常。
然后，我将我的项目导出为 .war 文件，并将其放在我只能通过 ssh 访问的另一台机器中我的 tomcat 的 webapps 目录下。我重新启动了我的 tomcat 服务器，在查看日志文件后，我发现它抛出了以下异常：
java.lang.NoSuchMethodException: org.apache.catalina.deploy.WebXml addServlet
at org.apache.tomcat.util.IntrospectionUtils.callMethod1(IntrospectionUtils.java:855)
at org.apache.tomcat.util.digester.SetNextRule.end(SetNextRule.java:201)
at org.apache.tomcat.util.digester.Digester.endElement(Digester.java:1051)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.endElement(AbstractSAXParser.java:604)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanEndElement(XMLDocumentFragmentScannerImpl.java:1759)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2915)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:625)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:488)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:819)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:748)
at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:123)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1208)
at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:525)
at org.apache.tomcat.util.digester.Digester.parse(Digester.java:1537)
at org.apache.catalina.startup.ContextConfig.parseWebXml(ContextConfig.java:1875)
at org.apache.catalina.startup.ContextConfig.getDefaultWebXmlFragment(ContextConfig.java:1472)
at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1250)
at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:878)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:369)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5173)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:633)
at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:968)
at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1646)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
at java.util.concurrent.FutureTask.run(FutureTask.java:166)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:679)
不知道这意味着什么？