一个爬虫方法报错了，

Question

com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine handleJavaScriptException
信息: Caught script exception
======= EXCEPTION START ========
Exception class=[net.sourceforge.htmlunit.corejs.javascript.EvaluatorException]
com.gargoylesoftware.htmlunit.ScriptException: Invalid negative index: -1 (http://www.youdao.com/scripts/tgl.js#1)
	at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine$HtmlUnitContextAction.run(JavaScriptEngine.java:669)
	at net.sourceforge.htmlunit.corejs.javascript.Context.call(Context.java:601)
	at net.sourceforge.htmlunit.corejs.javascript.ContextFactory.call(ContextFactory.java:507)
	at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine.execute(JavaScriptEngine.java:555)
	at com.gargoylesoftware.htmlunit.html.HtmlPage.loadExternalJavaScriptFile(HtmlPage.java:1082)
	at com.gargoylesoftware.htmlunit.html.HtmlScript.executeScriptIfNeeded(HtmlScript.java:399)
	at com.gargoylesoftware.htmlunit.html.HtmlScript$3.execute(HtmlScript.java:260)
	at com.gargoylesoftware.htmlunit.html.HtmlScript.onAllChildrenAddedToPage(HtmlScript.java:276)
	at com.gargoylesoftware.htmlunit.html.HTMLParser$HtmlUnitDOMBuilder.endElement(HTMLParser.java:680)
	at org.apache.xerces.parsers.AbstractSAXParser.endElement(Unknown Source)
	at com.gargoylesoftware.htmlunit.html.HTMLParser$HtmlUnitDOMBuilder.endElement(HTMLParser.java:639)
	at org.cyberneko.html.HTMLTagBalancer.callEndElement(HTMLTagBalancer.java:1170)
	at org.cyberneko.html.HTMLTagBalancer.endElement(HTMLTagBalancer.java:1072)
	at org.cyberneko.html.filters.DefaultFilter.endElement(DefaultFilter.java:206)
	at org.cyberneko.html.filters.NamespaceBinder.endElement(NamespaceBinder.java:330)
	at org.cyberneko.html.HTMLScanner$ContentScanner.scanEndElement(HTMLScanner.java:3074)
	at org.cyberneko.html.HTMLScanner$ContentScanner.scan(HTMLScanner.java:2041)
	at org.cyberneko.html.HTMLScanner.scanDocument(HTMLScanner.java:918)
	at org.cyberneko.html.HTMLConfiguration.parse(HTMLConfiguration.java:499)
	at org.cyberneko.html.HTMLConfiguration.parse(HTMLConfiguration.java:452)
	at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
	at com.gargoylesoftware.htmlunit.html.HTMLParser$HtmlUnitDOMBuilder.parse(HTMLParser.java:897)
	at com.gargoylesoftware.htmlunit.html.HTMLParser.parse(HTMLParser.java:243)
	at com.gargoylesoftware.htmlunit.html.HTMLParser.parseHtml(HTMLParser.java:188)
	at com.gargoylesoftware.htmlunit.DefaultPageCreator.createHtmlPage(DefaultPageCreator.java:268)
	at com.gargoylesoftware.htmlunit.DefaultPageCreator.createPage(DefaultPageCreator.java:156)
	at com.gargoylesoftware.htmlunit.WebClient.loadWebResponseInto(WebClient.java:434)
	at com.gargoylesoftware.htmlunit.WebClient.getPage(WebClient.java:309)
	at com.gargoylesoftware.htmlunit.WebClient.getPage(WebClient.java:374)
	at org.openqa.selenium.htmlunit.HtmlUnitDriver.get(HtmlUnitDriver.java:363)
	at org.openqa.selenium.htmlunit.HtmlUnitDriver.get(HtmlUnitDriver.java:350)
	at com.spider.main.web.EmailSpder.main(EmailSpder.java:92)
Caused by: net.sourceforge.htmlunit.corejs.javascript.EvaluatorException: Invalid negative index: -1 (http://www.youdao.com/scripts/tgl.js#1)
	at com.gargoylesoftware.htmlunit.javascript.StrictErrorReporter.runtimeError(StrictErrorReporter.java:81)
	at net.sourceforge.htmlunit.corejs.javascript.Context.reportRuntimeError(Context.java:1028)
	at net.sourceforge.htmlunit.corejs.javascript.Context.reportRuntimeError(Context.java:1075)
	at com.gargoylesoftware.htmlunit.javascript.host.css.StyleSheetList.item(StyleSheetList.java:118)
	at com.gargoylesoftware.htmlunit.javascript.host.css.StyleSheetList.get(StyleSheetList.java:145)
	at net.sourceforge.htmlunit.corejs.javascript.ScriptableObject.getProperty(ScriptableObject.java:2358)
	at net.sourceforge.htmlunit.corejs.javascript.ScriptRuntime.getObjectIndex(ScriptRuntime.java:1518)
	at net.sourceforge.htmlunit.corejs.javascript.ScriptRuntime.getObjectIndex(ScriptRuntime.java:1509)
	at net.sourceforge.htmlunit.corejs.javascript.Interpreter.doGetElem(Interpreter.java:2302)
	at net.sourceforge.htmlunit.corejs.javascript.Interpreter.interpretLoop(Interpreter.java:1267)
	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:275)
	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$3.doRun(JavaScriptEngine.java:546)
	at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine$HtmlUnitContextAction.run(JavaScriptEngine.java:654)
	... 31 more
Enclosed exception: 
net.sourceforge.htmlunit.corejs.javascript.EvaluatorException: Invalid negative index: -1 (http://www.youdao.com/scripts/tgl.js#1)
	at com.gargoylesoftware.htmlunit.javascript.StrictErrorReporter.runtimeError(StrictErrorReporter.java:81)
	at net.sourceforge.htmlunit.corejs.javascript.Context.reportRuntimeError(Context.java:1028)
	at net.sourceforge.htmlunit.corejs.javascript.Context.reportRuntimeError(Context.java:1075)
	at com.gargoylesoftware.htmlunit.javascript.host.css.StyleSheetList.item(StyleSheetList.java:118)
	at com.gargoylesoftware.htmlunit.javascript.host.css.StyleSheetList.get(StyleSheetList.java:145)
	at net.sourceforge.htmlunit.corejs.javascript.ScriptableObject.getProperty(ScriptableObject.java:2358)
	at net.sourceforge.htmlunit.corejs.javascript.ScriptRuntime.getObjectIndex(ScriptRuntime.java:1518)
	at net.sour

Answer 1

写爬虫的童鞋可以试试神箭手云爬虫，自带JS渲染、代理ip、验证码识别等功能，还可以发布和导出爬取的数据，生成图表等，都在云端进行，不需要安装开发环境。