我认为这是一个典型的用例。我正在使用Apache HttpClient对远程（内部）服务器进行POST。服务器的响应是XML。
我从实体获得响应作为流并将其直接解析为XML文档。此代码段显示了我正在做的事情。
HttpResponse response = httpClient.execute(request);
int code = response.getStatusLine().getStatusCode();
if(code != 200) {
returnValue.addParameter("msg", "Recieved invalid status code '" + code + "'");
}
else {
HttpEntity entity = response.getEntity();
if (entity != null) {
InputStream iStream = entity.getContent();
try {
DocumentBuilder db = DocumentBuilderFactory.newInstance().newDocumentBuilder();
Document doc = db.parse(iStream);
在我的开发箱上运行时，一切正常。但是，当我将其部署到我们的某个内部服务器时，我的代码段db.parse(iStream)的最后一行会出现连接超时异常。
为什么？
我的理解（和Fiddler）说，当我向实体询问内容时，请求已完成。因此，输入流不会通过网络传输，因此应该非常快！
任何人都有想法会发生什么事情？
非常感谢提前
更新，这是我得到的堆栈跟踪
java.net.ConnectException: Connection timed out: connect
at java.net.DualStackPlainSocketImpl.connect0(Native Method) ~[?:1.7.0_80]
at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:79) ~[?:1.7.0_80]
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339) ~[?:1.7.0_80]
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200) ~[?:1.7.0_80]
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182) ~[?:1.7.0_80]
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172) ~[?:1.7.0_80]
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) ~[?:1.7.0_80]
at java.net.Socket.connect(Socket.java:579) ~[?:1.7.0_80]
at java.net.Socket.connect(Socket.java:528) ~[?:1.7.0_80]
at sun.net.NetworkClient.doConnect(NetworkClient.java:180) ~[?:1.7.0_80]
at sun.net.www.http.HttpClient.openServer(HttpClient.java:432) ~[?:1.7.0_80]
at sun.net.www.http.HttpClient.openServer(HttpClient.java:527) ~[?:1.7.0_80]
at sun.net.www.http.HttpClient.<init>(HttpClient.java:211) ~[?:1.7.0_80]
at sun.net.www.http.HttpClient.New(HttpClient.java:308) ~[?:1.7.0_80]
at sun.net.www.http.HttpClient.New(HttpClient.java:326) ~[?:1.7.0_80]
at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(HttpURLConnection.java:997) ~[?:1.7.0_80]
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:933) ~[?:1.7.0_80]
at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:851) ~[?:1.7.0_80]
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1301) ~[?:1.7.0_80]
at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.setupCurrentEntity(XMLEntityManager.java:643) ~[?:1.7.0_80]
at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.startEntity(XMLEntityManager.java:1297) ~[?:1.7.0_80]
at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.startDTDEntity(XMLEntityManager.java:1264) ~[?:1.7.0_80]
at com.sun.org.apache.xerces.internal.impl.XMLDTDScannerImpl.setInputSource(XMLDTDScannerImpl.java:263) ~[?:1.7.0_80]
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.dispatch(XMLDocumentScannerImpl.java:1164) ~[?:1.7.0_80]
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.next(XMLDocumentScannerImpl.java:1050) ~[?:1.7.0_80]
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:964) ~[?:1.7.0_80]
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:606) ~[?:1.7.0_80]
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:510) ~[?:1.7.0_80]
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:848) ~[?:1.7.0_80]
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:777) ~[?:1.7.0_80]
at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141) ~[?:1.7.0_80]
at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:243) ~[?:1.7.0_80]
at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:347) ~[?:1.7.0_80]
at javax.xml.parsers.DocumentBuilder.parse(DocumentBuilder.java:121) ~[?:1.7.0_80]
at com.XXXXXX.YYYYY.harness.server.Api.postCxml(Api.java:183) [classes/:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.7.0_80]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) ~[?:1.7.0_80]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.7.0_80]
at java.lang.reflect.Method.invoke(Method.java:606) ~[?:1.7.0_80]
at org.glassfish.jersey.server.model.internal.ResourceMethodInvocationHandlerFactory$1.invoke(ResourceMethodInvocationHandlerFactory.java:81) [jersey-server-2.22.2.jar:?]
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher$1.run(AbstractJavaResourceMethodDispatcher.java:144) [jersey-server-2.22.2.jar:?]
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.invoke(AbstractJavaResourceMethodDispatcher.java:161) [jersey-server-2.22.2.jar:?]
at org.glassfish.jersey.server.model.internal.JavaResourceMethodDispatcherProvider$ResponseOutInvoker.doDispatch(JavaResourceMethodDispatcherProvider.java:160) [jersey-server-2.22.2.jar:?]
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.dispatch(AbstractJavaResourceMethodDispatcher.java:99) [jersey-server-2.22.2.jar:?]
at org.glassfish.jersey.server.model.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:389) [jersey-server-2.22.2.jar:?]
at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:347) [jersey-server-2.22.2.jar:?]
at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:102) [jersey-server-2.22.2.jar:?]
at org.glassfish.jersey.server.ServerRuntime$2.run(ServerRuntime.java:326) [jersey-server-2.22.2.jar:?]
at org.glassfish.jersey.internal.Errors$1.call(Errors.java:271) [jersey-common-2.22.2.jar:?]
at org.glassfish.jersey.internal.Errors$1.call(Errors.java:267) [jersey-common-2.22.2.jar:?]
at org.glassfish.jersey.internal.Errors.process(Errors.java:315) [jersey-common-2.22.2.jar:?]
at org.glassfish.jersey.internal.Errors.process(Errors.java:297) [jersey-common-2.22.2.jar:?]
at org.glassfish.jersey.internal.Errors.process(Errors.java:267) [jersey-common-2.22.2.jar:?]
at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:317) [jersey-common-2.22.2.jar:?]
at org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:305) [jersey-server-2.22.2.jar:?]
at org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:1154) [jersey-server-2.22.2.jar:?]
at org.glassfish.jersey.servlet.WebComponent.serviceImpl(WebComponent.java:473) [jersey-container-servlet-core-2.22.2.jar:?]
at org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:427) [jersey-container-servlet-core-2.22.2.jar:?]
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:388) [jersey-container-servlet-core-2.22.2.jar:?]
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:341) [jersey-container-servlet-core-2.22.2.jar:?]
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:228) [jersey-container-servlet-core-2.22.2.jar:?]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291) [catalina.jar:8.0.30]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) [catalina.jar:8.0.30]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) [tomcat-websocket.jar:8.0.30]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) [catalina.jar:8.0.30]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) [catalina.jar:8.0.30]
at org.apache.logging.log4j.web.Log4jServletFilter.doFilter(Log4jServletFilter.java:71) [log4j-web-2.5.jar:2.5]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) [catalina.jar:8.0.30]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) [catalina.jar:8.0.30]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212) [catalina.jar:8.0.30]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106) [catalina.jar:8.0.30]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502) [catalina.jar:8.0.30]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141) [catalina.jar:8.0.30]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) [catalina.jar:8.0.30]
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616) [catalina.jar:8.0.30]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) [catalina.jar:8.0.30]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:521) [catalina.jar:8.0.30]
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1096) [tomcat-coyote.jar:8.0.30]
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:674) [tomcat-coyote.jar:8.0.30]
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2500) [tomcat-coyote.jar:8.0.30]
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2489) [tomcat-coyote.jar:8.0.30]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [?:1.7.0_80]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [?:1.7.0_80]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-util.jar:8.0.30]
at java.lang.Thread.run(Thread.java:745) [?:1.7.0_80]
答案 0 :(得分：2)
您是否可以发布确切的错误消息，并且可以发布回复的内容以查看其中的内容吗？
但对我而言，这听起来像是网络/安全设置中的一个问题。
或许DocumentBuilder尝试通过XML文档的网络套接字访问DTD失败了吗？如果XML文档中有DTD引用，请尝试编辑它们以证明原因。
答案 1 :(得分：2)
正如KilleKat指出这是由于DocumentBuilder试图验证外部DTD。我用过这篇文章
Make DocumentBuilder.parse ignore DTD references
并将我的代码修改为
HttpResponse response = httpClient.execute(request);
int code = response.getStatusLine().getStatusCode();
if(code != 200) {
returnValue.addParameter("msg", "Recieved invalid status code '" + code + "'");
}
else {
HttpEntity entity = response.getEntity();
if (entity != null) {
InputStream iStream = entity.getContent();
try {
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
dbf.setValidating(false);
dbf.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);
DocumentBuilder db = dbf.newDocumentBuilder();
Document doc = db.parse(iStream);