未连接到 Internet 时的 Jetty http 查找

Question

我有一个嵌入式码头服务器，它使用码头 9。我正在尝试使用主机 = localhost 和端口 = 8080 运行它的本地实例，现在当我的机器连接到互联网时它运行良好。但是如果不是，它会引发异常 - 知道如何解决这个问题吗？

java.net.UnknownHostException: java.sun.com
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.<init>(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:996)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:932)
at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:850)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1300)
at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.setupCurrentEntity(XMLEntityManager.java:637)
at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.startEntity(XMLEntityManager.java:1290)
at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.startDTDEntity(XMLEntityManager.java:1257)
at com.sun.org.apache.xerces.internal.impl.XMLDTDScannerImpl.setInputSource(XMLDTDScannerImpl.java:262)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.dispatch(XMLDocumentScannerImpl.java:1162)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.next(XMLDocumentScannerImpl.java:1050)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:964)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:606)
at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:117)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:510)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:848)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:777)
at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1213)
at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:649)
at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl.parse(SAXParserImpl.java:333)
at org.eclipse.jetty.xml.XmlParser.parse(XmlParser.java:246)
at org.eclipse.jetty.webapp.Descriptor.parse(Descriptor.java:65)
at org.eclipse.jetty.webapp.WebDescriptor.parse(WebDescriptor.java:181)
at org.eclipse.jetty.webapp.MetaData.setWebXml(MetaData.java:172)
at org.eclipse.jetty.webapp.WebXmlConfiguration.preConfigure(WebXmlConfiguration.java:60)
at org.eclipse.jetty.webapp.WebAppContext.preConfigure(WebAppContext.java:455)
at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:491)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:69)
at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:117)
at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:99)
at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:60)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:69)
at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:117)
at org.eclipse.jetty.server.Server.start(Server.java:355)
at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:99)
at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:60)
at org.eclipse.jetty.server.Server.doStart(Server.java:324)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:69)

Answer 1

添加

<dependency>
   <groupId>org.eclipse.jetty.toolchain</groupId>
    <artifactId>jetty-schemas</artifactId>
    <version>3.1</version>
</dependency>

为我解决了问题。

见：https://issues.apache.org/jira/browse/BROOKLYN-197

Answer 2

可能您在 XML 文件中有一些配置。 XML 可以是格式良好的，甚至可以根据DTD 检查。如果 DTD 位于 Internet 上并且您没有连接，则 XMLParser 可能会失败。

可能是您的 XML 配置文件中的拼写错误，因为 DTD 通常包含在 JAR 中。

Answer 3

从 web.xml 中删除以下 dtd 解决了这个问题。

<!DOCTYPE web-app PUBLIC "-//Sun Microsystems, 

Inc.//DTD Web 应用程序 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd">