Unable to load configuration.-Class: java.net. plainsocketimpl

When Tomcat is started, an error is reported:

Severe: exception starting filter struts2
Unable to load configuration.-Class: java.net. plainsocketimpl
File: plainsocketimpl. Java
Method: connect
Line: 177-Java/NET/plainsocketimpl. Java: 177:-1
At com. opensymphony. xwork2.config. configurationmanager. getconfiguration (configurationmanager. Java
At org. Apache. struts2.dispatcher. Dispatcher. init_preloadconfiguration (dispatcher. Java: 371)
At org. Apache. struts2.dispatcher. Dispatcher. INIT (dispatcher. Java: 424)
At org. Apache. struts2.dispatcher. filterdispatcher. INIT (filterdispatcher. Java: 213)
At org. Apache. Catalina. Core. applicationfilterconfig. getfilter (applicationfilterconfig. Java: 275)
At org. Apache. Catalina. Core. applicationfilterconfig. setfilterdef (applicationfilterconfig. Java: 397)
At org. Apache. Catalina. Core. applicationfilterconfig. <init> (applicationfilterconfig. Java
At org. Apache. Catalina. Core. standardcontext. filterstart (standardcontext. Java: 3709)
At org. Apache. Catalina. Core. standardcontext. Start (standardcontext. Java: 4356)
At org. Apache. Catalina. Core. containerbase. Start (containerbase. Java: 1045)
At org. Apache. Catalina. Core. standardhost. Start (standardhost. Java: 719)
At org. Apache. Catalina. Core. containerbase. Start (containerbase. Java: 1045)
At org. Apache. Catalina. Core. standardengine. Start (standardengine. Java: 443)
At org. Apache. Catalina. Core. standardservice. Start (standardservice. Java: 516)
At org. Apache. Catalina. Core. standardserver. Start (standardserver. Java: 710)
At org. Apache. Catalina. startup. Catalina. Start (Catalina. Java: 578)
At sun. Reflect. nativemethodaccessorimpl. invoke0 (native method)
At sun. Reflect. nativemethodaccessorimpl. Invoke (nativemethodaccessorimpl. Java
At sun. Reflect. delegatingmethodaccessorimpl. Invoke (delegatingmethodaccessorimpl. Java
At java. Lang. Reflect. method. Invoke (method. Java: 597)
At org. Apache. Catalina. startup. Bootstrap. Start (Bootstrap. Java: 288)
At org. Apache. Catalina. startup. Bootstrap. Main (Bootstrap. Java: 413)
Caused by: Unable to Load file:/D:/eclipsework/langsin/flextdemotest2/webcontent/WEB-INF/classes/struts. XML-class: java.net. plainsocketimpl
File: plainsocketimpl. Java
Method: connect
Line: 177-Java/NET/plainsocketimpl. Java: 177:-1
At com. opensymphony. xwork2.config. providers. xmlconfigurationprovider. loadconfigurationfiles (xmlconfigurationprovider. Java: 875)
At com. opensymphony. xwork2.config. providers. xmlconfigurationprovider. loadconfigurents (xmlconfigurationprovider. Java: 161)
At com. opensymphony. xwork2.config. providers. xmlconfigurationprovider. INIT (xmlconfigurationprovider. Java: 130)
At com. opensymphony. xwork2.config. impl. defaultconfiguration. reloadcontainer (defaultconfiguration. Java: 155)
At com. opensymphony. xwork2.config. configurationmanager. getconfiguration (configurationmanager. Java
... 21 more
Caused by: struts.apache.org-class: java.net. plainsocketimpl
File: plainsocketimpl. Java
Method: connect
Line: 177-Java/NET/plainsocketimpl. Java: 177:-1
At com. opensymphony. xwork2.util. domhelper. parse (domhelper. Java: 122)
At com. opensymphony. xwork2.config. providers. xmlconfigurationprovider. loadconfigurationfiles (xmlconfigurationprovider. Java: 870)
... 25 more
Caused by: java.net. unknownhostexception: struts.apache.org
At java.net. plainsocketimpl. Connect (plainsocketimpl. Java: 177)
At java.net. Socket. Connect (socket. Java: 519)
At java.net. Socket. Connect (socket. Java: 469)
At sun.net. networkclient. doconnect (networkclient. Java: 157)
At sun.net. www. http. httpclient. openserver (httpclient. Java: 394)
At sun.net. www. http. httpclient. openserver (httpclient. Java: 529)
At sun.net. www. http. httpclient. <init> (httpclient. Java: 233)
At sun.net. www. http. httpclient. New (httpclient. Java: 306)
At sun.net. www. http. httpclient. New (httpclient. Java: 323)
At sun.net. www. Protocol. http. httpurlconnection. getnewhttpclient (httpurlconnection. Java: 788)
At sun.net. www. Protocol. http. httpurlconnection. plainconnect (httpurlconnection. Java: 729)
At sun.net. www. Protocol. http. httpurlconnection. Connect (httpurlconnection. Java: 654)
At sun.net. www. Protocol. http. httpurlconnection. getinputstream (httpurlconnection. Java: 977)
At com.sun.org. Apache. xerces. Internal. impl. xmlentitymanager. setupcurrententity (xmlentitymanager. Java: 677)
At com.sun.org. Apache. xerces. Internal. impl. xmlentitymanager. startentity (xmlentitymanager. Java: 1315)
At com.sun.org. Apache. xerces. Internal. impl. xmlentitymanager. startdtdentity (xmlentitymanager. Java: 1282)
At com.sun.org. Apache. xerces. Internal. impl. xmldtdscannerimpl. setinputsource (xmldtdscannerimpl. Java: 283)
At com.sun.org. Apache. xerces. Internal. impl. xmldocumentscannerimpl $ dtddriver. Dispatch (xmldocumentscannerimpl. Java: 1176)
At com.sun.org. Apache. xerces. Internal. impl. xmldocumentscannerimpl $ dtddriver. Next (xmldocumentscannerimpl. Java: 1075)
At com.sun.org. Apache. xerces. Internal. impl. xmldocumentscannerimpl $ prologdriver. Next (xmldocumentscannerimpl. Java: 993)
At com.sun.org. Apache. xerces. Internal. impl. xmldocumentscannerimpl. Next (xmldocumentscannerimpl. Java: 647)
At com.sun.org. Apache. xerces. Internal. impl. xmlnsdocumentscannerimpl. Next (xmlnsdocumentscannerimpl. Java: 140)
At com.sun.org. Apache. xerces. Internal. impl. xmldocumentfragmentscannerimpl. scandocument (xmldocumentfragmentscannerimpl. Java: 508)
At com.sun.org. Apache. xerces. Internal. parsers. xml11configuration. parse (xml11configuration. Java: 807)
At com.sun.org. Apache. xerces. Internal. parsers. xml11configuration. parse (xml11configuration. Java: 737)
At com.sun.org. Apache. xerces. Internal. parsers. xmlparser. parse (xmlparser. Java
At com.sun.org. Apache. xerces. Internal. parsers. abstractsaxparser. parse (abstractsaxparser. Java: 1205)
At com.sun.org. Apache. xerces. Internal. JAXP. saxparserimpl $ jaxpsaxparser. parse (saxparserimpl. Java: 522)
At javax. xml. parsers. saxparser. parse (saxparser. Java: 395)
At com. opensymphony. xwork2.util. domhelper. parse (domhelper. Java
... 26 more
2009-5-9 15:56:51 org. Apache. Catalina. Core. standardcontext start

 

Cause and solution:

If it is good to connect to the Internet and run again after the network is disconnected, the above problem will occur.

Therefore, the Internet connection problem is solved.