我觉得这不起作用的原因是我错误地导入selenium-server-standalone-3.9.1.jar，但我不确定如何解决这个问题。
bash命令：

java -cp "byte-buddy-1.8.15.jar:commons-exec-1.3.jar:guava-25.0-jre.jar:okhttp-3.11.0.jar:okio-1.14.0.jar:selenium-server-standalone-3.9.1.jar:client-combined-3.141.59.jar:client-combined-3.141.59.jar" launchBrowser.java

终端出错：

launchBrowser.java:3: error: package org.openqa.selenium does not exist
import org.openqa.selenium.By;

launchBrowser.java:4: error: package org.openqa.selenium does not exist
import org.openqa.selenium.WebDriver;

launchBrowser.java:5: error: package org.openqa.selenium.chrome does not exist
import org.openqa.selenium.chrome.ChromeDriver;

launchBrowser.java:12: error: cannot find symbol
        WebDriver driver = new ChromeDriver();

  symbol:   class WebDriver
  location: class launchBrowser
launchBrowser.java:12: error: cannot find symbol
        WebDriver driver = new ChromeDriver();

  symbol:   class ChromeDriver
  location: class launchBrowser
launchBrowser.java:15: error: cannot find symbol
        driver.findElement(By.id("identifierId")).sendKeys("@gmail.com");

  symbol:   variable By
  location: class launchBrowser
launchBrowser.java:16: error: cannot find symbol
        driver.findElement(By.className("dwads")).click();

  symbol:   variable By
  location: class launchBrowser
7 errors
error: compilation failed

我的代码：

package selenium.webdriver;
import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;

public class launchBrowser {
    public static void main(String [] args) {
        System.setProperty("webdriver.chrome.driver", "/chromedriver_main/");
        WebDriver driver = new ChromeDriver();
        driver.get("https://www.gmail.com");
        driver.manage().window().maximize();
        driver.findElement(By.id("identifierId")).sendKeys("@gmail.com");
        driver.findElement(By.className("VfPpkd-RLmnJb")).click();
        String at = driver.getTitle();
        String et = "gmail";
        driver.close();
    }
}