struts2

问题：

严重: 文档无效: 找不到语法。 at (null:3:8)
org.xml.sax.SAXParseException; systemId: file:/D:/project/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/Web/WEB-INF/classes/struts.xml; lineNumber: 3; columnNumber: 8; 文档无效: 找不到语法。
 at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(Unknown Source)
 at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.error(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanStartElement(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl$NSContentDriver.scanRootElementHook(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
 at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown Source)
 at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown Source)
 at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(Unknown Source)
 at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(Unknown Source)
 at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source)
 at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl.parse(Unknown Source)
 at com.opensymphony.xwork2.util.DomHelper.parse(DomHelper.java:117)
 at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadConfigurationFiles(XmlConfigurationProvider.java:1021)
 at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadDocuments(XmlConfigurationProvider.java:167)
 at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.init(XmlConfigurationProvider.java:134)
 at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:239)
 at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:67)
 at org.apache.struts2.dispatcher.Dispatcher.getContainer(Dispatcher.java:978)
 at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:446)
 at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:490)
 at org.apache.struts2.dispatcher.ng.InitOperations.initDispatcher(InitOperations.java:74)
 at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:57)
 at org.apache.catalina.core.ApplicationFilterConfig.initFilter(ApplicationFilterConfig.java:281)
 at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:262)
 at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:107)
 at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4775)
 at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5452)
 at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
 at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
 at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
 at java.util.concurrent.FutureTask.run(Unknown Source)
 at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
 at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
 at java.lang.Thread.run(Unknown Source)

九月 18, 2017 11:45:03 下午 com.opensymphony.xwork2.util.logging.jdk.JdkLogger error
严重: Dispatcher initialization failed
Unable to load configuration. - file:/D:/project/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/Web/WEB-INF/classes/struts.xml:3:8
 at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:70)
 at org.apache.struts2.dispatcher.Dispatcher.getContainer(Dispatcher.java:978)
 at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:446)
 at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:490)
 at org.apache.struts2.dispatcher.ng.InitOperations.initDispatcher(InitOperations.java:74)
 at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:57)
 at org.apache.catalina.core.ApplicationFilterConfig.initFilter(ApplicationFilterConfig.java:281)
 at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:262)
 at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:107)
 at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4775)
 at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5452)
 at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
 at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
 at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
 at java.util.concurrent.FutureTask.run(Unknown Source)
 at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
 at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
 at java.lang.Thread.run(Unknown Source)
Caused by: Unable to load file:/D:/project/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/Web/WEB-INF/classes/struts.xml - file:/D:/project/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/Web/WEB-INF/classes/struts.xml:3:8
 at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadConfigurationFiles(XmlConfigurationProvider.java:1027)
 at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadDocuments(XmlConfigurationProvider.java:167)
 at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.init(XmlConfigurationProvider.java:134)
 at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:239)
 at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:67)
 ... 17 more
Caused by: 文档无效: 找不到语法。 - file:/D:/project/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/Web/WEB-INF/classes/struts.xml:3:8
 at com.opensymphony.xwork2.util.DomHelper.parse(DomHelper.java:119)
 at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadConfigurationFiles(XmlConfigurationProvider.java:1021)
 ... 21 more
Caused by: org.xml.sax.SAXParseException; systemId: file:/D:/project/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/Web/WEB-INF/classes/struts.xml; lineNumber: 3; columnNumber: 8; 文档无效: 找不到语法。
 at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(Unknown Source)
 at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.error(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanStartElement(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl$NSContentDriver.scanRootElementHook(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.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 com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl.parse(Unknown Source)
 at com.opensymphony.xwork2.util.DomHelper.parse(DomHelper.java:117)
 ... 22 more

九月 18, 2017 11:45:03 下午 org.apache.catalina.core.StandardContext filterStart
严重: Exception starting filter Struts2
Unable to load configuration. - file:/D:/project/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/Web/WEB-INF/classes/struts.xml:3:8
 at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:504)
 at org.apache.struts2.dispatcher.ng.InitOperations.initDispatcher(InitOperations.java:74)
 at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:57)
 at org.apache.catalina.core.ApplicationFilterConfig.initFilter(ApplicationFilterConfig.java:281)
 at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:262)
 at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:107)
 at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4775)
 at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5452)
 at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
 at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
 at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
 at java.util.concurrent.FutureTask.run(Unknown Source)
 at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
 at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
 at java.lang.Thread.run(Unknown Source)
Caused by: Unable to load configuration. - file:/D:/project/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/Web/WEB-INF/classes/struts.xml:3:8
 at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:70)
 at org.apache.struts2.dispatcher.Dispatcher.getContainer(Dispatcher.java:978)
 at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:446)
 at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:490)
 ... 14 more
Caused by: Unable to load file:/D:/project/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/Web/WEB-INF/classes/struts.xml - file:/D:/project/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/Web/WEB-INF/classes/struts.xml:3:8
 at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadConfigurationFiles(XmlConfigurationProvider.java:1027)
 at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadDocuments(XmlConfigurationProvider.java:167)
 at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.init(XmlConfigurationProvider.java:134)
 at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:239)
 at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:67)
 ... 17 more
Caused by: 文档无效: 找不到语法。 - file:/D:/project/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/Web/WEB-INF/classes/struts.xml:3:8
 at com.opensymphony.xwork2.util.DomHelper.parse(DomHelper.java:119)
 at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadConfigurationFiles(XmlConfigurationProvider.java:1021)
 ... 21 more
Caused by: org.xml.sax.SAXParseException; systemId: file:/D:/project/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/Web/WEB-INF/classes/struts.xml; lineNumber: 3; columnNumber: 8; 文档无效: 找不到语法。
 at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(Unknown Source)
 at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.error(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanStartElement(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl$NSContentDriver.scanRootElementHook(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(Unknown Source)
 at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.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 com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl.parse(Unknown Source)
 at com.opensymphony.xwork2.util.DomHelper.parse(DomHelper.java:117)
 ... 22 more

九月 18, 2017 11:45:03 下午 org.apache.catalina.core.StandardContext startInternal
严重: Error filterStart
九月 18, 2017 11:45:03 下午 org.apache.catalina.core.StandardContext startInternal
严重: Context [/Web] startup failed due to previous errors
九月 18, 2017 11:45:03 下午 org.apache.coyote.AbstractProtocol start
信息: Starting ProtocolHandler ["http-bio-8080"]
九月 18, 2017 11:45:03 下午 org.apache.coyote.AbstractProtocol start
信息: Starting ProtocolHandler ["ajp-bio-8009"]
九月 18, 2017 11:45:03 下午 org.apache.catalina.startup.Catalina start
信息: Server startup in 1510 ms

解决方法：

   在struts.xml中添加：

        <!DOCTYPE struts PUBLIC
   "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
   "http://struts.apache.org//dtds/struts-2.3dtd">