错误E：使用HtmlUnit执行javascript

我正在尝试在以下url上执行javascript： http://steamcommunity.com/id/bobcatchris/inventory#730 ： http://steamcommunity.com/id/bobcatchris/inventory#730 。 我可以通过按ctrl + shift + j并粘贴以下脚本打开控制台，使用谷歌浏览器：

 var list = []; var size = Object.keys(g_ActiveInventory.rgInventory).size(); var counter = 0; while (counter < size) { list.push(g_ActiveInventory.rgInventory[Object.keys(g_ActiveInventory.rgInventory)[counter]].market_name); counter +=1; } 

它返回：150然后在下一行，我写： >list ，它返回一个长度为150的数组。

当我尝试在HtmlUnit执行此操作时：

  public static void main(String[] args) throws IOException { WebClient webClient=new WebClient(BrowserVersion.FIREFOX_17); HtmlPage page=webClient.getPage("http://steamcommunity.com/id/bobcatchris/inventory#730"); String script="var list = [];\n" + "\n" + "\n" + "var size = Object.keys(g_ActiveInventory.rgInventory).size();\n" + "\n" + "\n" + "\n" + "var counter = 0;\n" + "\n" + "while (counter < size) {\n" + " list.push(g_ActiveInventory.rgInventory[Object.keys(g_ActiveInventory.rgInventory)[counter]].market_name);\n" + " counter +=1;\n" + "}"; Object result = page.executeJavaScript(script).getJavaScriptResult(); System.out.println(result); } 

我收到以下exception：

 Exception in thread "main" ======= EXCEPTION START ======== EcmaError: lineNumber=[4] column=[0] lineSource=[] name=[TypeError] sourceName=[injected script] message=[TypeError: Expected argument of type object, but instead had type object (injected script#4)] com.gargoylesoftware.htmlunit.ScriptException: TypeError: Expected argument of type object, but instead had type object (injected script#4) at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine$HtmlUnitContextAction.run(JavaScriptEngine.java:684) at net.sourceforge.htmlunit.corejs.javascript.Context.call(Context.java:602) at net.sourceforge.htmlunit.corejs.javascript.ContextFactory.call(ContextFactory.java:507) at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine.execute(JavaScriptEngine.java:570) at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine.execute(JavaScriptEngine.java:545) at com.gargoylesoftware.htmlunit.html.HtmlPage.executeJavaScriptIfPossible(HtmlPage.java:959) at com.gargoylesoftware.htmlunit.html.HtmlPage.executeJavaScript(HtmlPage.java:927) at Scraper.main(Scraper.java:32) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:601) at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120) Caused by: net.sourceforge.htmlunit.corejs.javascript.EcmaError: TypeError: Expected argument of type object, but instead had type object (injected script#4) at net.sourceforge.htmlunit.corejs.javascript.ScriptRuntime.constructError(ScriptRuntime.java:3603) at net.sourceforge.htmlunit.corejs.javascript.ScriptRuntime.constructError(ScriptRuntime.java:3587) at net.sourceforge.htmlunit.corejs.javascript.ScriptRuntime.typeError(ScriptRuntime.java:3608) at net.sourceforge.htmlunit.corejs.javascript.ScriptRuntime.typeError1(ScriptRuntime.java:3618) at net.sourceforge.htmlunit.corejs.javascript.ScriptableObject.ensureScriptable(ScriptableObject.java:2095) at net.sourceforge.htmlunit.corejs.javascript.NativeObject.execIdCall(NativeObject.java:287) at net.sourceforge.htmlunit.corejs.javascript.IdFunctionObject.call(IdFunctionObject.java:89) at net.sourceforge.htmlunit.corejs.javascript.Interpreter.interpretLoop(Interpreter.java:1531) at net.sourceforge.htmlunit.corejs.javascript.Interpreter.interpret(Interpreter.java:798) at net.sourceforge.htmlunit.corejs.javascript.InterpretedFunction.call(InterpretedFunction.java:105) at net.sourceforge.htmlunit.corejs.javascript.ContextFactory.doTopCall(ContextFactory.java:405) at com.gargoylesoftware.htmlunit.javascript.HtmlUnitContextFactory.doTopCall(HtmlUnitContextFactory.java:309) at net.sourceforge.htmlunit.corejs.javascript.ScriptRuntime.doTopCall(ScriptRuntime.java:3031) at net.sourceforge.htmlunit.corejs.javascript.InterpretedFunction.exec(InterpretedFunction.java:115) at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine$3.doRun(JavaScriptEngine.java:561) at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine$HtmlUnitContextAction.run(JavaScriptEngine.java:669) ... 12 more Enclosed exception: net.sourceforge.htmlunit.corejs.javascript.EcmaError: TypeError: Expected argument of type object, but instead had type object (injected script#4) at net.sourceforge.htmlunit.corejs.javascript.ScriptRuntime.constructError(ScriptRuntime.java:3603) at net.sourceforge.htmlunit.corejs.javascript.ScriptRuntime.constructError(ScriptRuntime.java:3587) at net.sourceforge.htmlunit.corejs.javascript.ScriptRuntime.typeError(ScriptRuntime.java:3608) at net.sourceforge.htmlunit.corejs.javascript.ScriptRuntime.typeError1(ScriptRuntime.java:3618) at net.sourceforge.htmlunit.corejs.javascript.ScriptableObject.ensureScriptable(ScriptableObject.java:2095) at net.sourceforge.htmlunit.corejs.javascript.NativeObject.execIdCall(NativeObject.java:287) at net.sourceforge.htmlunit.corejs.javascript.IdFunctionObject.call(IdFunctionObject.java:89) at net.sourceforge.htmlunit.corejs.javascript.Interpreter.interpretLoop(Interpreter.java:1531) at script(injected script:4) at net.sourceforge.htmlunit.corejs.javascript.Interpreter.interpret(Interpreter.java:798) at net.sourceforge.htmlunit.corejs.javascript.InterpretedFunction.call(InterpretedFunction.java:105) at net.sourceforge.htmlunit.corejs.javascript.ContextFactory.doTopCall(ContextFactory.java:405) at com.gargoylesoftware.htmlunit.javascript.HtmlUnitContextFactory.doTopCall(HtmlUnitContextFactory.java:309) at net.sourceforge.htmlunit.corejs.javascript.ScriptRuntime.doTopCall(ScriptRuntime.java:3031) at net.sourceforge.htmlunit.corejs.javascript.InterpretedFunction.exec(InterpretedFunction.java:115) at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine$3.doRun(JavaScriptEngine.java:561) at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine$HtmlUnitContextAction.run(JavaScriptEngine.java:669) at net.sourceforge.htmlunit.corejs.javascript.Context.call(Context.java:602) at net.sourceforge.htmlunit.corejs.javascript.ContextFactory.call(ContextFactory.java:507) at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine.execute(JavaScriptEngine.java:570) at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine.execute(JavaScriptEngine.java:545) at com.gargoylesoftware.htmlunit.html.HtmlPage.executeJavaScriptIfPossible(HtmlPage.java:959) at com.gargoylesoftware.htmlunit.html.HtmlPage.executeJavaScript(HtmlPage.java:927) at Scraper.main(Scraper.java:32) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:601) at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120) ======= EXCEPTION END ======== 

造成例外的一行是：

 Object result = page.executeJavaScript(script).getJavaScriptResult(); 

那么我应该如何从谷歌Chrome控制台那样从HtmlUnit执行这个脚本呢？

Answer 1

这些是您的框架错误转换为Java exceptions的javascript脚本错误。

那是因为您没有将WebClient的setThrowExceptionOnScriptError选项显式设置为false 。

除非js中绝对没有错误，否则始终将此值设置为false非常有用，除非它干扰您正在查找的结果。

通常，这些是我通过HtmlUnit处理js和ajax时的webclient设置。

 final WebClient webClient = new WebClient(BrowserVersion.FIREFOX_17, PROXY_HOST, PROXY_PORT); WebRequest request = new WebRequest(new URL( "http://steamcommunity.com/id/bobcatchris/inventory#730")); webClient.getOptions().setThrowExceptionOnScriptError(false); webClient.setJavaScriptTimeout(10000); webClient.getOptions().setJavaScriptEnabled(true); webClient.setAjaxController(new NicelyResynchronizingAjaxController()); webClient.getOptions().setTimeout(10000); HtmlPage page = webClient.getPage(request); String script="var list = [];\n" + "\n" + "\n" + "var size = Object.keys(g_ActiveInventory.rgInventory).size();\n" + "\n" + "\n" + "\n" + "var counter = 0;\n" + "\n" + "while (counter < size) {\n" + " list.push(g_ActiveInventory.rgInventory[Object.keys(g_ActiveInventory.rgInventory)[counter]].market_name);\n" + " counter +=1;\n" + "}"; Object result = page.executeJavaScript(script).getJavaScriptResult(); System.out.println(result); 

如果我尝试你的代码，使用上面的设置我得到150.0打印到控制台，我认为这是按预期工作。

编辑：

遍历完整的数组list ：

 String script="var list = [];\n" + "\n" + "\n" + "var size = Object.keys(g_ActiveInventory.rgInventory).size();\n" + "\n" + "\n" + "\n" + "var counter = 0;\n" + "\n" + "while (counter < size) {\n" + " list.push(g_ActiveInventory.rgInventory[Object.keys(g_ActiveInventory.rgInventory)[counter]].market_name);\n" + " counter +=1;\n" + "}" + "list"; Object result = page.executeJavaScript(script).getJavaScriptResult(); if (result instanceof NativeArray) { for (Object obj : (NativeArray)result) { System.out.println(obj); } } 

上面，我已经将js更改为包含list作为返回参数，并迭代NativeArray以获取每个元素。

输出：

 P2000 | Scorpion (Factory New) AK-47 | Black Laminate (Field-Tested) ★ StatTrak™ Karambit | Case Hardened (Minimal Wear) CS:GO Case Key CS:GO Case Key 

您可以在他们的常见问题解答中阅读他们的ajax设置 - 这里 。