无意间struts应用在有网络的情况下启动正常，在断网的情况下启动报错，报错代码如下图所示：

SEVERE: Exception starting filter struts2Class: java.net.AbstractPlainSocketImplFile: AbstractPlainSocketImpl.javaMethod: connectLine: 178 - java/net/AbstractPlainSocketImpl.java:178:-1    at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadConfigurationFiles(XmlConfigurationProvider.java:835)    at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadDocuments(XmlConfigurationProvider.java:131)    at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.init(XmlConfigurationProvider.java:100)    at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reload(DefaultConfiguration.java:130)    at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:52)    at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:395)    at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:452)    at org.apache.struts2.dispatcher.FilterDispatcher.init(FilterDispatcher.java:201)    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.
     
      (ApplicationFilterConfig.java:107)    at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4746)    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5399)    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:633)    at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:657)    at org.apache.catalina.startup.HostConfig$DeployDescriptor.run(HostConfig.java:1636)    at java.util.concurrent.Executors$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: struts.apache.org - Class: java.net.AbstractPlainSocketImplFile: AbstractPlainSocketImpl.javaMethod: connectLine: 178 - java/net/AbstractPlainSocketImpl.java:178:-1    at com.opensymphony.xwork2.util.DomHelper.parse(DomHelper.java:123)    at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadConfigurationFiles(XmlConfigurationProvider.java:830)    ... 24 moreCaused by: java.net.UnknownHostException: struts.apache.org    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:178)    at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:157)    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:391)    at java.net.Socket.connect(Socket.java:579)    at java.net.Socket.connect(Socket.java:528)    at sun.net.NetworkClient.doConnect(NetworkClient.java:180)    at sun.net.www.http.HttpClient.openServer(HttpClient.java:378)    at sun.net.www.http.HttpClient.openServer(HttpClient.java:473)    at sun.net.www.http.HttpClient.
      
       (HttpClient.java:203)    at sun.net.www.http.HttpClient.New(HttpClient.java:290)    at sun.net.www.http.HttpClient.New(HttpClient.java:306)    at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(HttpURLConnection.java:995)    at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:931)    at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:849)    at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1299)    at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.setupCurrentEntity(XMLEntityManager.java:632)    at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.startEntity(XMLEntityManager.java:1270)    at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.startDTDEntity(XMLEntityManager.java:1237)    at com.sun.org.apache.xerces.internal.impl.XMLDTDScannerImpl.setInputSource(XMLDTDScannerImpl.java:260)    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.dispatch(XMLDocumentScannerImpl.java:1153)    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.next(XMLDocumentScannerImpl.java:1049)    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:962)    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:607)    at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:116)    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:489)    at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:835)    at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:764)    at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:123)    at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1210)    at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:568)    at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl.parse(SAXParserImpl.java:302)    at com.opensymphony.xwork2.util.DomHelper.parse(DomHelper.java:121)    ... 25 more三月 20, 2014 9:25:36 上午 org.apache.catalina.core.StandardContext startInternal
      
     

查看struts.xml文件的DOCTYPE定义如下：

1 

再查看xwork的jar包是2.0的，所以将DOCTYPE的定义也改成2.0的即可

1