我已经用Java中的Selenium库编写了一些逻辑，以执行一些简单的Web抓取（该逻辑对这个问题并不重要），当从我的Java Web项目中的简单测试文件的main（）函数运行时，这些抓取可以工作。当我尝试移动此逻辑代码，甚至只是从我的实际servlet或JSP文件中调用此代码时，服务器会因以下异常而崩溃：
java.lang.NoSuchMethodError: com.google.common.base.Preconditions.checkState(ZLjava/lang/String;Ljava/lang/Object;)V
at org.openqa.selenium.remote.service.DriverService.checkExecutable(DriverService.java:136)
at org.openqa.selenium.firefox.GeckoDriverService.access$000(GeckoDriverService.java:41)
at org.openqa.selenium.firefox.GeckoDriverService$Builder.usingFirefoxBinary(GeckoDriverService.java:108)
at org.openqa.selenium.firefox.FirefoxDriver.toExecutor(FirefoxDriver.java:204)
at org.openqa.selenium.firefox.FirefoxDriver.<init>(FirefoxDriver.java:103)
at org.openqa.selenium.firefox.FirefoxDriver.<init>(FirefoxDriver.java:99)
at scraping.OneCardScraper.<init>(OneCardScraper.java:41)
at org.apache.jsp.Home_jsp._jspService(Home_jsp.java:212)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:111)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:411)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:473)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:377)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:416)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:283)
at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:206)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:180)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:283)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:200)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:132)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:111)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:536)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:591)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:571)
at java.lang.Thread.run(Thread.java:745)
错误指向此行：
driver = new FirefoxDriver();我在这里做错了什么？
我对为什么Selenium依赖关系可能在Web平台上而不是在典型的测试运行中遇到麻烦感到困惑，因为依赖关系应该继续存在。
我试过了：
多次重新启动IDE
清洁，建筑等
将整个项目迁移到基于Maven的依赖系统
更改硒中的浏览器类型（PhantomJS，HTMLUnit，Chrome，FireFox）
将Webdriver位置变量添加到web.xml上下文参数中
我在用：
Netbeans 8.2
Java EE 7
硒3.5.3
最佳答案
这基本上意味着番石榴依赖关系中的冲突。
您可能要检查此硒commit和这些番石榴21 release notes。最新的Selenium版本需要Guava 21+，而Guava 21+需要Java8。因此，您必须降级Selenium或升级Java以避免此类问题。