java – Selenium：http：// localhost：4444 / wd / hub返回Nul

var url = new Uri("http://localhost:4444/wd/hub");
var wd = new RemoteWebDriver(url,DesiredCapabilities.Chrome());

上面的新RemoteWebDriver代码在超时后才会响应…

更多细节

我已经使用这些参数启动了我的Hub到Selenium Server：

-jar "C:SomeFolderselenium-server-standalone-3.0.1.jar" -port 4444 -role hub

并使用这些parms注册了一个节点..

-jar "C:SomeFolderselenium-server-standalone-3.0.1.jar" -role node -hub http://localhost:4444/grid/register -port 9662

调试

如果我在启动集线器后输入此URL,则表明存在已注册的节点：

http://location:4444/grid/console

但是在启动Hub后输入此URL时

http://localhost:4444/wd/hub

浏览器显示指向ExternalSessionKey.java的此java(json)堆栈跟踪

{"status":13,"value":{"class":"java.lang.NullPointerException","stackTrace":[{"fileName":"ExternalSessionKey.java","className":"org.openqa.grid.internal.ExternalSessionKey","methodName":"fromWebDriverRequest","lineNumber":77},{"fileName":"WebDriverRequest.java","className":"org.openqa.grid.web.servlet.handler.WebDriverRequest","methodName":"extractSession","lineNumber":62},{"fileName":"RequestHandler.java","className":"org.openqa.grid.web.servlet.handler.RequestHandler","methodName":"getSession","lineNumber":231},"methodName":"process","lineNumber":118},{"fileName":"DriverServlet.java","className":"org.openqa.grid.web.servlet.DriverServlet","lineNumber":83},"methodName":"doGet","lineNumber":61},{"fileName":"HttpServlet.java","className":"javax.servlet.http.HttpServlet","methodName":"service","lineNumber":687},"lineNumber":790},{"fileName":"ServletHolder.java","className":"org.seleniumhq.jetty9.servlet.ServletHolder","methodName":"handle","lineNumber":808},{"fileName":"ServletHandler.java","className":"org.seleniumhq.jetty9.servlet.ServletHandler","methodName":"doHandle","lineNumber":587},{"fileName":"SessionHandler.java","className":"org.seleniumhq.jetty9.server.session.SessionHandler","lineNumber":221},{"fileName":"ContextHandler.java","className":"org.seleniumhq.jetty9.server.handler.ContextHandler","lineNumber":1127},"methodName":"doScope","lineNumber":515},"lineNumber":185},"lineNumber":1061},{"fileName":"ScopedHandler.java","className":"org.seleniumhq.jetty9.server.handler.ScopedHandler","lineNumber":141},{"fileName":"HandlerWrapper.java","className":"org.seleniumhq.jetty9.server.handler.HandlerWrapper","lineNumber":97},{"fileName":"Server.java","className":"org.seleniumhq.jetty9.server.Server","lineNumber":499},{"fileName":"HttpChannel.java","className":"org.seleniumhq.jetty9.server.HttpChannel","lineNumber":310},{"fileName":"HttpConnection.java","className":"org.seleniumhq.jetty9.server.HttpConnection","methodName":"onFillable","lineNumber":257},{"fileName":"AbstractConnection.java","className":"org.seleniumhq.jetty9.io.AbstractConnection$2","methodName":"run","lineNumber":540},{"fileName":"QueuedThreadPool.java","className":"org.seleniumhq.jetty9.util.thread.QueuedThreadPool","methodName":"runJob","lineNumber":635},"className":"org.seleniumhq.jetty9.util.thread.QueuedThreadPool$3","lineNumber":555},{"className":"java.lang.Thread","lineNumber":-1}]}}

任何人都可以为我解释Stack Trace,以及如何使其工作？

谢谢！