我使用HtmlUnit从网站获取一些信息。当我不在代理后面时它会起作用。在代理后面工作时，我使用此代码来设置配置：
WebClient webClient = new WebClient(BrowserVersion.FIREFOX_45);
ProxyConfig proxyConfig = new ProxyConfig();
proxyConfig.setProxyAutoConfigUrl(proxyAutoConfigUrl);
webClient.getOptions().setProxyConfig(proxyConfig);
HtmlPage page = webClient.getPage(config.read().getString("homepage.url"));
FrameWindow fw = page.getFrameByName("mainDataIframe");
...
但我总是收到错误：
ERROR AWT-EventQueue-0 com.gargoylesoftware.htmlunit.html.HtmlPage - Error loading JavaScript from [some website].
java.io.IOException: Unable to download JavaScript from 'some website' (status 404).
at com.gargoylesoftware.htmlunit.html.HtmlPage.loadJavaScriptFromUrl(HtmlPage.java:1040)
at com.gargoylesoftware.htmlunit.html.HtmlPage.loadExternalJavaScriptFile(HtmlPage.java:967)
at com.gargoylesoftware.htmlunit.html.HtmlScript.executeScriptIfNeeded(HtmlScript.java:352)
at com.gargoylesoftware.htmlunit.html.HtmlScript$2.execute(HtmlScript.java:238)
at com.gargoylesoftware.htmlunit.html.HtmlScript.onAllChildrenAddedToPage(HtmlScript.java:257)
at com.gargoylesoftware.htmlunit.html.HTMLParser$HtmlUnitDOMBuilder.endElement(HTMLParser.java:772)
at org.apache.xerces.parsers.AbstractSAXParser.endElement(Unknown Source)
at com.gargoylesoftware.htmlunit.html.HTMLParser$HtmlUnitDOMBuilder.endElement(HTMLParser.java:729)
at net.sourceforge.htmlunit.cyberneko.HTMLTagBalancer.callEndElement(HTMLTagBalancer.java:1209)
at net.sourceforge.htmlunit.cyberneko.HTMLTagBalancer.endElement(HTMLTagBalancer.java:1111)
at net.sourceforge.htmlunit.cyberneko.filters.DefaultFilter.endElement(DefaultFilter.java:207)
at net.sourceforge.htmlunit.cyberneko.filters.NamespaceBinder.endElement(NamespaceBinder.java:337)
at net.sourceforge.htmlunit.cyberneko.HTMLScanner$ContentScanner.scanEndElement(HTMLScanner.java:3137)
at net.sourceforge.htmlunit.cyberneko.HTMLScanner$ContentScanner.scan(HTMLScanner.java:2100)
at net.sourceforge.htmlunit.cyberneko.HTMLScanner.scanDocument(HTMLScanner.java:927)
at net.sourceforge.htmlunit.cyberneko.HTMLConfiguration.parse(HTMLConfiguration.java:506)
at net.sourceforge.htmlunit.cyberneko.HTMLConfiguration.parse(HTMLConfiguration.java:459)
at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
at com.gargoylesoftware.htmlunit.html.HTMLParser$HtmlUnitDOMBuilder.parse(HTMLParser.java:979)
at com.gargoylesoftware.htmlunit.html.HTMLParser.parse(HTMLParser.java:241)
at com.gargoylesoftware.htmlunit.html.HTMLParser.parseHtml(HTMLParser.java:187)
at com.gargoylesoftware.htmlunit.DefaultPageCreator.createHtmlPage(DefaultPageCreator.java:269)
at com.gargoylesoftware.htmlunit.DefaultPageCreator.createPage(DefaultPageCreator.java:157)
at com.gargoylesoftware.htmlunit.WebClient.loadWebResponseInto(WebClient.java:511)
at com.gargoylesoftware.htmlunit.WebClient.getPage(WebClient.java:385)
at com.gargoylesoftware.htmlunit.WebClient.getPage(WebClient.java:303)
at com.gargoylesoftware.htmlunit.WebClient.getPage(WebClient.java:450)
at com.gargoylesoftware.htmlunit.WebClient.getPage(WebClient.java:435)
at com.bayer.elwasweb.PageReader.messstellenDurchlaufen(PageReader.java:99)
at com.bayer.elwasweb.PageReader.start(PageReader.java:70)
at com.bayer.elwasweb.Gui.actionPerformed(Gui.java:211)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$500(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
ERROR AWT-EventQueue-0 PageReader - com.gargoylesoftware.htmlunit.ElementNotFoundException: elementName=[frame or iframe] attributeName=[name] attributeValue=[mainDataIframe]
如果没有代理或在浏览器中，此错误永远不会发生。是否有人有想法，为什么会发生这种错误？或者也许有人知道如何在代理背后工作时找到差异？
答案 0 :(得分：1)
我们想通了！异常/错误具有误导性。
错误消息导致我们得出结论，问题是没有加载引发异常的JavaScript文件。实际上整个页面都没有加载。
代理只需要一些凭据。我们添加了
final DefaultCredentialsProvider credentialsProvider =
(DefaultCredentialsProvider) webClient.getCredentialsProvider();
credentialsProvider.addCredentials(username, password);
到WebClient configuartaions。