读取mybatis xml文件时会出现“java.net.UnknownHostException”
我喜欢通过java代码从mybatis xml文件中读取数据。 （不是mybatis映射，只是想从应用程序外部读取数据。）
SELECT id,name,standard,age,sex FROM user; 所以我尝试使用xml阅读器如下：
File fXmlFile = new File("c:\\mybatis.xml"); DocumentBuilderFactory dbFactory = DocumentBuilderFactory .newInstance(); DocumentBuilder dBuilder = dbFactory.newDocumentBuilder(); Document doc = dBuilder.parse(fXmlFile); doc.getDocumentElement().normalize(); NodeList nList = doc.getElementsByTagName("mapper"); . . .
但是，当我运行此代码时，我得到了以下错误
java.net.UnknownHostException: mybatis.org at java.net.AbstractPlainSocketImpl.connect(Unknown Source) at java.net.PlainSocketImpl.connect(Unknown Source) at java.net.SocksSocketImpl.connect(Unknown Source) at java.net.Socket.connect(Unknown Source) at java.net.Socket.connect(Unknown Source) at sun.net.NetworkClient.doConnect(Unknown Source) at sun.net.www.http.HttpClient.openServer(Unknown Source) at sun.net.www.http.HttpClient.openServer(Unknown Source) at sun.net.www.http.HttpClient.(Unknown Source) at sun.net.www.http.HttpClient.New(Unknown Source) at sun.net.www.http.HttpClient.New(Unknown Source) at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(Unknown Source) at sun.net.www.protocol.http.HttpURLConnection.plainConnect(Unknown Source) at sun.net.www.protocol.http.HttpURLConnection.connect(Unknown Source) at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source) at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.setupCurrentEntity(Unknown Source) at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.startEntity(Unknown Source) at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.startDTDEntity(Unknown Source) at com.sun.org.apache.xerces.internal.impl.XMLDTDScannerImpl.setInputSource(Unknown Source) at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.dispatch(Unknown Source) at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.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.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.DOMParser.parse(Unknown Source) at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(Unknown Source) at javax.xml.parsers.DocumentBuilder.parse(Unknown Source) at xmlReader.main(xmlReader.java:37)
由于这个陈述，我发现了错误的过程。
当我删除此语句时，我的所有代码都正常工作。 让我知道，我怎样才能克服这个问题。
可以通过在DocumentBuilderFactory上设置以下function来实现：
dbFactory.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);
例如：
File fXmlFile = new File("c:\\mybatis.xml"); DocumentBuilderFactory dbFactory = DocumentBuilderFactory .newInstance(); dbFactory.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false); DocumentBuilder dBuilder = dbFactory.newDocumentBuilder(); Document doc = dBuilder.parse(fXmlFile); doc.getDocumentElement().normalize();