SEVERE: End event threw exception java.lang.NoSuchMethodException: org.apache.catalina.deploy.WebXml addFilter 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:1063) at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.endElement(AbstractSAXParser.java:606) at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanEndElement(XMLDocumentFragmentScannerImpl.java:1742) at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2900) at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:607) at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:489) at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:835) at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:764) at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:123) at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1210) at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:568) at org.apache.tomcat.util.digester.Digester.parse(Digester.java:1561) at org.apache.catalina.startup.ContextConfig.parseWebXml(ContextConfig.java:1809) at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1247) at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:873) at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:371) at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117) at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5355) 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:632) at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1229) at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1875) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334) at java.util.concurrent.FutureTask.run(FutureTask.java:166) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at java.lang.Thread.run(Thread.java:722) 六月 12, 2014 7:22:06 下午 org.apache.catalina.startup.ContextConfig parseWebXml SEVERE: Parse error in application web.xml file at jndi:/localhost/carManager/WEB-INF/web.xml org.xml.sax.SAXParseException; systemId: jndi:/localhost/carManager/WEB-INF/web.xml; lineNumber: 33; columnNumber: 11; Error at (33, 11) : org.apache.catalina.deploy.WebXml addFilter at org.apache.tomcat.util.digester.Digester.createSAXException(Digester.java:2711) at org.apache.tomcat.util.digester.Digester.createSAXException(Digester.java:2743) at org.apache.tomcat.util.digester.Digester.endElement(Digester.java:1066) at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.endElement(AbstractSAXParser.java:606) at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanEndElement(XMLDocumentFragmentScannerImpl.java:1742) at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2900) at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:607) at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:489) at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:835) at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:764) at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:123) at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1210) at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:568) at org.apache.tomcat.util.digester.Digester.parse(Digester.java:1561) at org.apache.catalina.startup.ContextConfig.parseWebXml(ContextConfig.java:1809) at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1247) at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:873) at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:371) at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117) at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5355) 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:632) at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1229) at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1875) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334) at java.util.concurrent.FutureTask.run(FutureTask.java:166) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at java.lang.Thread.run(Thread.java:722) Caused by: java.lang.NoSuchMethodException: org.apache.catalina.deploy.WebXml addFilter 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:1063) ... 30 more 六月 12, 2014 7:22:06 下午 org.apache.catalina.startup.ContextConfig parseWebXml SEVERE: Occurred at line 33 column 11 六月 12, 2014 7:22:06 下午 org.apache.catalina.startup.ContextConfig configureStart SEVERE: Marking this application unavailable due to previous error(s) 六月 12, 2014 7:22:06 下午 org.apache.catalina.core.StandardContext startInternal SEVERE: Error getConfigured 六月 12, 2014 7:22:06 下午 org.apache.catalina.core.StandardContext startInternal SEVERE: Context [/carManager] startup failed due to previous errors
解决办法:
在tomacat的配置文件context.xml里加上<Loader delegate="true"/>
<Loader delegate="true"/>此参数的作用:
首先,你需要了解一下JVM的Classloader机制(详细请自行google之)。
简而言之,JVM的classloader加载继承关系分为BootstarpClassLoader --> ExtClassLoader --> SystemClassLoader,应用的WebAppClassLoader继承自SystemClassLoader,在加载具体某个类时,一般会先委托给父类ClassLoader,当父类ClassLoader无法加载成功时,才会再由子类ClassLoader尝试加载,这就是所谓的delegate机制。
其次,Tomcat在jvm的ClassLoader机制上增加了几个继承层次。
SystemClassLoader --> CommonClassLoader -->(ServerClassLoader | SharedClassLoader --> WebAppClassLoader)。
CommonClassLoader用来加载${CATALINA_HOME}/conf/catalina.properties中common.loader配置目录下的类文件,一般是用来加载${CATALINA_HOME}/lib下的文件。该loader加载的类为tomcat服务器和tomcat下面的所有webApp所共享。
ServerClassLoader用来加载${CATALINA_HOME}/conf/catalina.properties中server.loader配置目录下的类文件,一般是用来加载${CATALINA_HOME}/server下的文件。该loader加载的类为tomcat服务器所独有核心类,tomcat下面的WebApp无法访问。
SharedClassLoader用来加载${CATALINA_HOME}/conf/catalina.properties中shared.loader配置目录下的类文件,一般是用来加载${CATALINA_HOME}/shared下的文件。该loader加载的类为tomcat下面的所有webApp所共享。
WebAppClassLoader用来加载${CATALINA_HOME}/webapps/目录下每个WebApp应用的/WEB-INF/class,/WEB-INF/lib的类文件,每个WebApp对应一个WebAppClassLoader,用来加载其所需要的类文件。
最后,说一下delegate配置的意义。
True,表示tomcat将遵循JVM的delegate机制,即一个WebAppClassLoader在加载类文件时,会先递交给SharedClassLoader加载,SharedClassLoader无法加载成功,会继续向自己的父类委托,一直到BootstarpClassLoader,如果都没有加载成功,则最后由WebAppClassLoader自己进行加载。
False,表示将不遵循这个delegate机制,即WebAppClassLoader在加载类文件时,会优先自己尝试加载,如果加载失败,才会沿着继承链,依次委托父类加载。
在此说一下配置为False需要注意的问题:一旦配置为False,如果你在WebApp中自己定义了一个java.lang.String,则这个String类会有可能覆盖掉jdk中的String类,这也许不是你想要的结果。另外对于多个WebApp公用jar包,你可能会放到${CATALINA_HOME}/shared目录中共享,但是一不小心在应用的/WEB-INF/lib中也包含了一个同名的但版本不一致的jar的话,这就有可能会导致很多奇怪的问题。