HtmlUnit click() 事件不起作用并在 Java 中触发 ClassCastException答案

【问题标题】：HtmlUnit click() event does not work and triggers ClassCastException in JavaHtmlUnit click() 事件不起作用并在 Java 中触发 ClassCastException
【发布时间】：2017-09-09 16:58:22
【问题描述】：

我在 Java 应用程序中使用 HtmlUnit 来加载网页并提交其表单。我毫无问题地获得了表单和提交输入，但是当我在该元素上调用函数 click() 时，它触发了 Cast Exception 并且似乎没有执行 click 事件。这是我的 webClient 配置：

this.webClient = new WebClient(BrowserVersion.CHROME);

webClient.getOptions().setJavaScriptEnabled(true);
webClient.getOptions().setThrowExceptionOnScriptError(true);
webClient.getOptions().setCssEnabled(false);
webClient.setAjaxController(new NicelyResynchronizingAjaxController());
webClient.getOptions().setThrowExceptionOnScriptError(false);
webClient.getOptions().setRedirectEnabled(true);

final HtmlPage jobPage = webClient.getPage("https://mySite/j#edit-job?id="+job.getJobID());
webClient.waitForBackgroundJavaScript(15000);

这是页面加载和输入选择的代码：

HtmlForm form = jobPage.getFormByName("");
HtmlSubmitInput submit = null;
final List<HtmlInput> inputs = form.getInputsByName("");

for(HtmlInput input : inputs){

    if(input.getAttribute("id").equals("postFormSubmit")){
        submit = (HtmlSubmitInput)input;
        break;
    }
}


if(submit != null){
    try {
        HtmlPage confirmUpdate = submit.click();
        webClient.waitForBackgroundJavaScript(15000);

        System.out.println("response : \n\n");
        System.out.println(confirmUpdate.asText());
        System.out.println("end response");

    }
    catch(Exception e){
        e.printStackTrace();
    }
}
else {
    System.out.println("submit input non trouvé");
}

我还尝试通过以下方式手动执行一些 javascript：

jobPage.executeJavascript("javascript:document.getElementById('postFormSubmit').click();");

但我得到了同样的例外：

INFOS: Caught script exception
======= EXCEPTION START ========
Exception class=[java.lang.ClassCastException]
com.gargoylesoftware.htmlunit.ScriptException: com.gargoylesoftware.htmlunit.javascript.host.html.HTMLInputElement cannot be cast to com.gargoylesoftware.htmlunit.html.HtmlElement
    at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine$HtmlUnitContextAction.run(JavaScriptEngine.java:898)
    at net.sourceforge.htmlunit.corejs.javascript.Context.call(Context.java:637)
    at net.sourceforge.htmlunit.corejs.javascript.ContextFactory.call(ContextFactory.java:518)
    at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine.callFunction(JavaScriptEngine.java:827)
    at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine.callFunction(JavaScriptEngine.java:799)
    at com.gargoylesoftware.htmlunit.html.HtmlPage.executeJavaScriptFunctionIfPossible(HtmlPage.java:2470)
    at com.gargoylesoftware.htmlunit.javascript.host.event.EventListenersContainer.executeEventListeners(EventListenersContainer.java:259)
    at com.gargoylesoftware.htmlunit.javascript.host.event.EventListenersContainer.executeBubblingListeners(EventListenersContainer.java:325)
    at com.gargoylesoftware.htmlunit.javascript.host.event.EventTarget.fireEvent(EventTarget.java:188)
    at com.gargoylesoftware.htmlunit.html.DomElement$2.run(DomElement.java:1389)
    at net.sourceforge.htmlunit.corejs.javascript.Context.call(Context.java:637)
    at net.sourceforge.htmlunit.corejs.javascript.ContextFactory.call(ContextFactory.java:518)
    at com.gargoylesoftware.htmlunit.html.DomElement.fireEvent(DomElement.java:1394)
    at com.gargoylesoftware.htmlunit.html.DomElement.fireEvent(DomElement.java:1362)
    at com.gargoylesoftware.htmlunit.html.HtmlForm.submit(HtmlForm.java:116)
    at com.gargoylesoftware.htmlunit.html.HtmlSubmitInput.doClickStateUpdate(HtmlSubmitInput.java:90)
    at com.gargoylesoftware.htmlunit.html.DomElement.click(DomElement.java:999)
    at com.gargoylesoftware.htmlunit.html.DomElement.click(DomElement.java:944)
    at com.gargoylesoftware.htmlunit.html.DomElement.click(DomElement.java:884)
    at com.gargoylesoftware.htmlunit.html.DomElement.click(DomElement.java:865)
    at model.IndeedManip$2.run(IndeedManip.java:309)
    at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
    at java.util.concurrent.FutureTask.runAndReset(Unknown Source)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(Unknown Source)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.ClassCastException: com.gargoylesoftware.htmlunit.javascript.host.html.HTMLInputElement cannot be cast to com.gargoylesoftware.htmlunit.html.HtmlElement
    at com.gargoylesoftware.htmlunit.javascript.host.dom.AbstractList.addElementIds(AbstractList.java:541)
    at com.gargoylesoftware.htmlunit.javascript.host.dom.AbstractList.getIds(AbstractList.java:523)
    at net.sourceforge.htmlunit.corejs.javascript.ScriptRuntime.enumChangeObject(ScriptRuntime.java:2235)
    at net.sourceforge.htmlunit.corejs.javascript.ScriptRuntime.enumInit(ScriptRuntime.java:2136)
    at net.sourceforge.htmlunit.corejs.javascript.Interpreter.interpretLoop(Interpreter.java:1740)
    at net.sourceforge.htmlunit.corejs.javascript.Interpreter.interpret(Interpreter.java:800)
    at net.sourceforge.htmlunit.corejs.javascript.InterpretedFunction.call(InterpretedFunction.java:105)
    at net.sourceforge.htmlunit.corejs.javascript.NativeArray.iterativeMethod(NativeArray.java:1694)
    at net.sourceforge.htmlunit.corejs.javascript.NativeArray.execIdCall(NativeArray.java:405)
    at net.sourceforge.htmlunit.corejs.javascript.IdFunctionObject.call(IdFunctionObject.java:94)
    at net.sourceforge.htmlunit.corejs.javascript.ScriptRuntime.applyOrCall(ScriptRuntime.java:2575)
    at net.sourceforge.htmlunit.corejs.javascript.BaseFunction.execIdCall(BaseFunction.java:321)
    at net.sourceforge.htmlunit.corejs.javascript.IdFunctionObject.call(IdFunctionObject.java:94)
    at net.sourceforge.htmlunit.corejs.javascript.Interpreter.interpretLoop(Interpreter.java:1540)
    at net.sourceforge.htmlunit.corejs.javascript.Interpreter.interpret(Interpreter.java:800)
    at net.sourceforge.htmlunit.corejs.javascript.InterpretedFunction.call(InterpretedFunction.java:105)
    at net.sourceforge.htmlunit.corejs.javascript.NativeArray.iterativeMethod(NativeArray.java:1694)
    at net.sourceforge.htmlunit.corejs.javascript.NativeArray.execIdCall(NativeArray.java:405)
    at net.sourceforge.htmlunit.corejs.javascript.IdFunctionObject.call(IdFunctionObject.java:94)
    at net.sourceforge.htmlunit.corejs.javascript.ScriptRuntime.applyOrCall(ScriptRuntime.java:2575)
    at net.sourceforge.htmlunit.corejs.javascript.BaseFunction.execIdCall(BaseFunction.java:321)
    at net.sourceforge.htmlunit.corejs.javascript.IdFunctionObject.call(IdFunctionObject.java:94)
    at net.sourceforge.htmlunit.corejs.javascript.Interpreter.interpretLoop(Interpreter.java:1540)
    at net.sourceforge.htmlunit.corejs.javascript.Interpreter.interpret(Interpreter.java:800)
    at net.sourceforge.htmlunit.corejs.javascript.InterpretedFunction.call(InterpretedFunction.java:105)
    at net.sourceforge.htmlunit.corejs.javascript.ContextFactory.doTopCall(ContextFactory.java:416)
    at com.gargoylesoftware.htmlunit.javascript.HtmlUnitContextFactory.doTopCall(HtmlUnitContextFactory.java:292)
    at net.sourceforge.htmlunit.corejs.javascript.ScriptRuntime.doTopCall(ScriptRuntime.java:3264)
    at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine$4.doRun(JavaScriptEngine.java:820)
    at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine$HtmlUnitContextAction.run(JavaScriptEngine.java:883)
    ... 27 more
Enclosed exception: 
java.lang.ClassCastException: com.gargoylesoftware.htmlunit.javascript.host.html.HTMLInputElement cannot be cast to com.gargoylesoftware.htmlunit.html.HtmlElement
    at com.gargoylesoftware.htmlunit.javascript.host.dom.AbstractList.addElementIds(AbstractList.java:541)
    at com.gargoylesoftware.htmlunit.javascript.host.dom.AbstractList.getIds(AbstractList.java:523)
    at net.sourceforge.htmlunit.corejs.javascript.ScriptRuntime.enumChangeObject(ScriptRuntime.java:2235)
    at net.sourceforge.htmlunit.corejs.javascript.ScriptRuntime.enumInit(ScriptRuntime.java:2136)
    at net.sourceforge.htmlunit.corejs.javascript.Interpreter.interpretLoop(Interpreter.java:1740)
    at net.sourceforge.htmlunit.corejs.javascript.Interpreter.interpret(Interpreter.java:800)
    at net.sourceforge.htmlunit.corejs.javascript.InterpretedFunction.call(InterpretedFunction.java:105)
    at net.sourceforge.htmlunit.corejs.javascript.NativeArray.iterativeMethod(NativeArray.java:1694)
    at net.sourceforge.htmlunit.corejs.javascript.NativeArray.execIdCall(NativeArray.java:405)
    at net.sourceforge.htmlunit.corejs.javascript.IdFunctionObject.call(IdFunctionObject.java:94)
    at net.sourceforge.htmlunit.corejs.javascript.ScriptRuntime.applyOrCall(ScriptRuntime.java:2575)
    at net.sourceforge.htmlunit.corejs.javascript.BaseFunction.execIdCall(BaseFunction.java:321)
    at net.sourceforge.htmlunit.corejs.javascript.IdFunctionObject.call(IdFunctionObject.java:94)
    at net.sourceforge.htmlunit.corejs.javascript.Interpreter.interpretLoop(Interpreter.java:1540)
    at net.sourceforge.htmlunit.corejs.javascript.Interpreter.interpret(Interpreter.java:800)
    at net.sourceforge.htmlunit.corejs.javascript.InterpretedFunction.call(InterpretedFunction.java:105)
    at net.sourceforge.htmlunit.corejs.javascript.NativeArray.iterativeMethod(NativeArray.java:1694)
    at net.sourceforge.htmlunit.corejs.javascript.NativeArray.execIdCall(NativeArray.java:405)
    at net.sourceforge.htmlunit.corejs.javascript.IdFunctionObject.call(IdFunctionObject.java:94)
    at net.sourceforge.htmlunit.corejs.javascript.ScriptRuntime.applyOrCall(ScriptRuntime.java:2575)
    at net.sourceforge.htmlunit.corejs.javascript.BaseFunction.execIdCall(BaseFunction.java:321)
    at net.sourceforge.htmlunit.corejs.javascript.IdFunctionObject.call(IdFunctionObject.java:94)
    at net.sourceforge.htmlunit.corejs.javascript.Interpreter.interpretLoop(Interpreter.java:1540)
    at net.sourceforge.htmlunit.corejs.javascript.Interpreter.interpret(Interpreter.java:800)
    at net.sourceforge.htmlunit.corejs.javascript.InterpretedFunction.call(InterpretedFunction.java:105)
    at net.sourceforge.htmlunit.corejs.javascript.ContextFactory.doTopCall(ContextFactory.java:416)
    at com.gargoylesoftware.htmlunit.javascript.HtmlUnitContextFactory.doTopCall(HtmlUnitContextFactory.java:292)
    at net.sourceforge.htmlunit.corejs.javascript.ScriptRuntime.doTopCall(ScriptRuntime.java:3264)
    at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine$4.doRun(JavaScriptEngine.java:820)
    at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine$HtmlUnitContextAction.run(JavaScriptEngine.java:883)
    at net.sourceforge.htmlunit.corejs.javascript.Context.call(Context.java:637)
    at net.sourceforge.htmlunit.corejs.javascript.ContextFactory.call(ContextFactory.java:518)
    at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine.callFunction(JavaScriptEngine.java:827)
    at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine.callFunction(JavaScriptEngine.java:799)
    at com.gargoylesoftware.htmlunit.html.HtmlPage.executeJavaScriptFunctionIfPossible(HtmlPage.java:2470)
    at com.gargoylesoftware.htmlunit.javascript.host.event.EventListenersContainer.executeEventListeners(EventListenersContainer.java:259)
    at com.gargoylesoftware.htmlunit.javascript.host.event.EventListenersContainer.executeBubblingListeners(EventListenersContainer.java:325)
    at com.gargoylesoftware.htmlunit.javascript.host.event.EventTarget.fireEvent(EventTarget.java:188)
    at com.gargoylesoftware.htmlunit.html.DomElement$2.run(DomElement.java:1389)
    at net.sourceforge.htmlunit.corejs.javascript.Context.call(Context.java:637)
    at net.sourceforge.htmlunit.corejs.javascript.ContextFactory.call(ContextFactory.java:518)
    at com.gargoylesoftware.htmlunit.html.DomElement.fireEvent(DomElement.java:1394)
    at com.gargoylesoftware.htmlunit.html.DomElement.fireEvent(DomElement.java:1362)
    at com.gargoylesoftware.htmlunit.html.HtmlForm.submit(HtmlForm.java:116)
    at com.gargoylesoftware.htmlunit.html.HtmlSubmitInput.doClickStateUpdate(HtmlSubmitInput.java:90)
    at com.gargoylesoftware.htmlunit.html.DomElement.click(DomElement.java:999)
    at com.gargoylesoftware.htmlunit.html.DomElement.click(DomElement.java:944)
    at com.gargoylesoftware.htmlunit.html.DomElement.click(DomElement.java:884)
    at com.gargoylesoftware.htmlunit.html.DomElement.click(DomElement.java:865)
    at model.IndeedManip$2.run(IndeedManip.java:309)
    at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
    at java.util.concurrent.FutureTask.runAndReset(Unknown Source)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(Unknown Source)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
== CALLING JAVASCRIPT ==
  function (c) {
      return a.call(b.src, b.Mh, c);
  }
======= EXCEPTION END ========

据说这是一个强制转换异常，但我没有进行任何强制转换，错误位于click() 事件的行。

如果您知道使用 HtmlUnit 触发点击事件的另一种方法，请告诉我。

【问题讨论】：

在哪一行代码上抛出异常？
这个：HtmlPage confirmUpdate = submit.click();
在您使用它的页面上，该按钮如何提交？它是调用 Javascript 函数还是通过 HTML 提交？
请使用最新版本，并提供您的完整案例（附网址）
请阅读Under what circumstances may I add “urgent” or other similar phrases to my question, in order to obtain faster answers? - 总结是这不是解决志愿者的理想方式，并且可能会适得其反。请不要将此添加到您的问题中。

标签： java webclient htmlunit

【解决方案1】：

这刚刚通过提交 14092 和 14093 修复。

您可以从here 获取最新版本。

测试用例是：

/**
 * @throws Exception on test failure
 */
@Test
@Alerts(DEFAULT = "0,1,2,3,4,5,entries,forEach,item,keys,length,values",
        IE = "0,1,2,3,4,5,item,length")
public void iterator() throws Exception {
    final String html = "<html><head><title>test</title>\n"
            + "<script>\n"
            + "  function test() {\n"
            + "    var all = [];\n"
            + "    for (var i in document.querySelectorAll('*')) {\n"
            + "      all.push(i);\n"
            + "    }\n"
            + "    all.sort(sortFunction);\n"
            + "    alert(all);\n"
            + "  }\n"
            + "  function sortFunction(s1, s2) {\n"
            + "    return s1.toLowerCase() > s2.toLowerCase() ? 1 : -1;\n"
            + "  }\n"
            + "</script>\n"
            + "</head><body onload='test()'>\n"
            + "  <div>/div>\n"
            + "</body></html>";

    loadPageWithAlerts2(html);
}

【讨论】：

非常感谢！不再抛出异常，但由于某些原因，我的表单仍未提交......当我执行click() 事件时，它只会刷新页面......你知道这可能来自哪里吗？如果网站检测到我们正在使用 java，或者 java 无法编译每个异步调用？
顺便说一下，我在网页上检测到一条消息，告诉我“正在加载...服务器错误，请稍后再试抱歉！您似乎处于隐私浏览模式，这不支持。请切换浏览器模式。”。你知道为什么吗？提前致谢

【解决方案2】：

感谢 Ahmed Ashour，此函数不再触发异常，但 HtmlUnit 从未提交过我的表单。

最后我改用 Selenium，它对 javascript 的执行效率更高。我建议任何从事 Web 抓取应用程序的人，该应用程序提交 ajax 驱动的表单以使用 Selenium

【讨论】：