tomcat无法启动

2010-6-25 20:36:25 org.apache.tomcat.util.digester.Digester startElement
严重: Begin event threw error
java.lang.NoClassDefFoundError: javax/servlet/http/HttpServletRequest
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(Unknown Source)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.access$000(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Unknown Source)
at java.lang.Class.privateGetPublicMethods(Unknown Source)
at java.lang.Class.getMethods(Unknown Source)
at org.apache.tomcat.util.IntrospectionUtils.findMethods(IntrospectionUtils.java:812)
at org.apache.tomcat.util.IntrospectionUtils.setProperty(IntrospectionUtils.java:268)
at org.apache.catalina.startup.SetAllPropertiesRule.begin(SetAllPropertiesRule.java:59)
at org.apache.tomcat.util.digester.Digester.startElement(Digester.java:1276)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.startElement(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanStartElement(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(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 com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source)
at org.apache.tomcat.util.digester.Digester.parse(Digester.java:1562)
at org.apache.catalina.startup.Catalina.load(Catalina.java:490)
at org.apache.catalina.startup.Catalina.load(Catalina.java:524)
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.catalina.startup.Bootstrap.load(Bootstrap.java:267)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:432)
Caused by: java.lang.ClassNotFoundException: javax.servlet.http.HttpServletRequest
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 38 more
tomcat无法启动了，怎么办。急，在线等。