Caused by: java.net.UnknownHostException: mybatis.org        at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:178)        at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)        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:432)        at sun.net.www.http.HttpClient.openServer(HttpClient.java:527)        at sun.net.www.http.HttpClient.
    
     (HttpClient.java:211)        at sun.net.www.http.HttpClient.New(HttpClient.java:308)        at sun.net.www.http.HttpClient.New(HttpClient.java:326)        at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(HttpURLConnection.java:997)        at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:933)        at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:851)        at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1301)        at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.setupCurrentEntity(XMLEntityManager.java:643)        at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.startEntity(XMLEntityManager.java:1297)        at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.startDTDEntity(XMLEntityManager.java:1264)        at com.sun.org.apache.xerces.internal.impl.XMLDTDScannerImpl.setInputSource(XMLDTDScannerImpl.java:263)        at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.dispatch(XMLDocumentScannerImpl.java:1164)        at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.next(XMLDocumentScannerImpl.java:1050)        at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:964)        at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:606)        at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:510)        at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:848)        at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:777)        at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141)        at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:243)        at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:347)        at org.springframework.beans.factory.xml.DefaultDocumentLoader.loadDocument(DefaultDocumentLoader.java:75)        at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:388)
    

原因：

服务器部署内网，不连网.

mybatis-config.xml配置头为：

内网找不到

http://mybatis.org/dtd/mybatis-3-config.dtd

这个dtd文件，先下载下来，然后放到mybatis-config.xml同路径下，然后修改头为：

问题解决。