在eclipse 启动tomcat 时候， 控制台给出这样的错误：
2007-5-13 21:57:52 org.apache.coyote.http11.Http11Protocol init
信息: Initializing Coyote HTTP/1.1 on http-8080
Starting service Tomcat-Standalone
Apache Tomcat/4.1.31
2007-5-13 21:57:53 org.apache.struts.util.PropertyMessageResources <init>
信息: Initializing, config= 'org.apache.struts.util.LocalStrings ', returnNull=true
2007-5-13 21:57:53 org.apache.struts.util.PropertyMessageResources <init>
信息: Initializing, config= 'org.apache.struts.action.ActionResources ', returnNull=true
2007-5-13 21:57:54 org.apache.struts.util.PropertyMessageResources <init>
信息: Initializing, config= 'org.apache.webapp.admin.ApplicationResources ', returnNull=true
2007-5-13 21:57:55 org.apache.commons.digester.Digester error
严重: Parse Error at line 6 column 52: Document root element "web-app ", must match DOCTYPE root "null ".
org.xml.sax.SAXParseException: Document root element "web-app ", must match DOCTYPE root "null ".
at org.apache.xerces.util.ErrorHandlerWrapper.createSAXParseException(Unknown Source)
at org.apache.xerces.util.ErrorHandlerWrapper.error(Unknown Source)
at org.apache.xerces.impl.XMLErrorReporter.reportError(Unknown Source)
at org.apache.xerces.impl.XMLErrorReporter.reportError(Unknown Source)
at org.apache.xerces.impl.dtd.XMLDTDValidator.rootElementSpecified(Unknown Source)
at org.apache.xerces.impl.dtd.XMLDTDValidator.handleStartElement(Unknown Source)
at org.apache.xerces.impl.dtd.XMLDTDValidator.startElement(Unknown Source)
at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanStartElement(Unknown Source)
at org.apache.xerces.impl.XMLDocumentScannerImpl$ContentDispatcher.scanRootElementHook(Unknown Source)
at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)
at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
at org.apache.xerces.parsers.DTDConfiguration.parse(Unknown Source)
at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
at org.apache.commons.digester.Digester.parse(Digester.java:1548)
at org.apache.catalina.startup.ContextConfig.applicationConfig(ContextConfig.java:220)
at org.apache.catalina.startup.ContextConfig.start(ContextConfig.java:579)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:181)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:3523)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:774)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:760)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:548)
at org.apache.catalina.core.StandardHostDeployer.install(StandardHostDeployer.java:260)
at org.apache.catalina.core.StandardHost.install(StandardHost.java:741)