我是硒自動化的新手，我已經遵循了網站的說明，并且使用了gecko驅動程序，但是它顯示以下消息。 64位），Selenium 3.12和gecko驅動程序20.1。Exception in thread "main" java.lang.IllegalStateException: The path to the driver executable must be set by the webdriver.gecko.driver system property; for more information, see https://github.com/mozilla/geckodriver. The latest version can be downloaded from https://github.com/mozilla/geckodriver/releases    at com.google.common.base.Preconditions.checkState(Preconditions.java:847)這是我的代碼包裝自動化框架;導入org.openqa.selenium.WebDriver; 導入org.openqa.selenium.firefox.FirefoxDriver;公共類userLogin {public static void main(String[] args){    System.setProperty("webdriver.gecko.driver ","E:\\\\Selenium\\\\geckodriver-v0.21.0-win64\\\\geckodriver.exe");    WebDriver driver = new FirefoxDriver();    driver.get("https://www.facebook.com/");}