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问题： 修改类文件，tomcat自动重启报错，请教高手描述:
2009-12-14 14:55:15 org.apache.catalina.loader.WebappClassLoader modified
信息: Additional JARs have been added : 'xercesImpl.jar'
2009-12-14 14:55:15 org.apache.catalina.core.StandardContext reload
信息: 已开始刷新这个上下文（Context）
2009-12-14 14:55:16 org.apache.catalina.loader.WebappClassLoader validateJarFile
信息: validateJarFile(E:\mailSHR\WebRoot\WEB-INF\lib\servlet.jar) - jar not loaded. See Servlet Spec 2.3, section 9.7.2. Offending class: javax/servlet/Servlet.class
2009-12-14 14:55:16 org.apache.catalina.startup.ContextConfig applicationWebConfig
严重: Parse error in application web.xml file at jndi:/localhost/WEB-INF/web.xml
java.lang.NullPointerException
at org.apache.xerces.impl.dtd.models.DFAContentModel.buildDFA(Unknown Source)
at org.apache.xerces.impl.dtd.models.DFAContentModel.
at org.apache.xerces.impl.dtd.DTDGrammar.createChildModel(Unknown Source)
at org.apache.xerces.impl.dtd.DTDGrammar.getElementContentModelValidator(Unknown Source)
at org.apache.xerces.impl.dtd.DTDGrammar.getElementDecl(Unknown Source)
at org.apache.xerces.impl.dtd.XMLDTDValidator.getContentSpecType(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.DTDConfiguration.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.tomcat.util.digester.Digester.parse(Digester.java:1561)
at org.apache.catalina.startup.ContextConfig.applicationWebConfig(ContextConfig.java:351)
at org.apache.catalina.startup.ContextConfig.start(ContextConfig.java:1041)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:260)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4143)
at org.apache.catalina.core.StandardContext.reload(StandardContext.java:3024)
at org.apache.catalina.loader.WebappLoader.backgroundProcess(WebappLoader.java:432)
at org.apache.catalina.core.ContainerBase.backgroundProcess(ContainerBase.java:1277)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1569)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1578)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1578)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.run(ContainerBase.java:1558)
at java.lang.Thread.run(Thread.java:595)
2009-12-14 14:55:16 org.apache.catalina.startup.ContextConfig start
严重: Marking this application unavailable due to previous error(s)
2009-12-14 14:55:16 org.apache.catalina.core.StandardContext start
严重: Error getConfigured
2009-12-14 14:55:16 org.apache.catalina.core.StandardContext start
严重: 因为前面的错误无法启动上下文
解决方案1:
xml解析包xerces.jar存在冲突，试试看你自己的lib里面的这个包删除它。
解决方案2: xerces
又看到这个包了。。。是不是用SPRING了
这个包有很大的兼容性问题，去掉再运行试试看
还有，竟然不要用自动重启，停掉服务 - 部属 - 启动服务