caused by:java.net.UnknownHostException:struts.apache.org

Start the project and report the mistake.

Line:184-java/net/abstractplainsocketimpl.java:184:-1
At Com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration (configurationmanager.java:70)
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:279)
At Org.apache.catalina.core.ApplicationFilterConfig.getFilter (applicationfilterconfig.java:260)
At Org.apache.catalina.core.applicationfilterconfig.<init> (applicationfilterconfig.java:105)
At Org.apache.catalina.core.StandardContext.filterStart (standardcontext.java:4809)
At Org.apache.catalina.core.StandardContext.startInternal (standardcontext.java:5485)
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 (futuretask.java:266)
At Java.util.concurrent.ThreadPoolExecutor.runWorker (threadpoolexecutor.java:1142)
At Java.util.concurrent.threadpoolexecutor$worker.run (threadpoolexecutor.java:617)
At Java.lang.Thread.run (thread.java:745)
caused By:unable to load File:/d:/apache-tomcat-7.0.52/webapps/graduatephotos/web-inf/classes/struts.xml-class : Java.net.AbstractPlainSocketImpl
File:AbstractPlainSocketImpl.java
Method:connect
Line:184-java/net/abstractplainsocketimpl.java:184:-1
At Com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadConfigurationFiles ( xmlconfigurationprovider.java:1022)
At Com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadDocuments ( xmlconfigurationprovider.java:165)
At Com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.init (xmlconfigurationprovider.java:132)
At Com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer (defaultconfiguration.java:225)
At Com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration (configurationmanager.java:67)
... More
caused By:struts.apache.org-class:java.net.abstractplainsocketimpl
File:AbstractPlainSocketImpl.java
Method:connect
Line:184-java/net/abstractplainsocketimpl.java:184:-1
At Com.opensymphony.xwork2.util.DomHelper.parse (domhelper.java:119)
At Com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadConfigurationFiles ( XMLCONFIGURATIONPROVIDER.JAVA:1017)
... More
caused by:java.net.UnknownHostException:struts.apache.org
At Java.net.AbstractPlainSocketImpl.connect (abstractplainsocketimpl.java:184)
At Java.net.PlainSocketImpl.connect (plainsocketimpl.java:172)
At Java.net.SocksSocketImpl.connect (sockssocketimpl.java:392)
At Java.net.Socket.connect (socket.java:589)
At Java.net.Socket.connect (socket.java:538)

The cause of the error is because there is no internet connection, it can not load "Http://struts.apache.org/dtds/struts-2.5.dtd This DTD file, so error, the solution in addition to the computer connected to the Internet, is to modify the"/HTTP STRUTS.APACHE.ORG/DTDS/STRUTS-2.5.DTD the corresponding file location, let it go from the local to find the DTD file, instead of loading the file online, as follows:

　　

DTD file in struts address: struts-2.3.15.3-all\src\core\src\main\resources

URL Address:

When this is set up, the DTD file can be loaded properly even without networking

caused by:java.net.UnknownHostException:struts.apache.org