Java代码如下(环境：eclipse Oxygen+JDK1.8+selenium3.8.1+Junit5+firefox48.0.2)

1.报错信息如下

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
1 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 fromhttps://github.com/mozilla/geckodriver/releases
2 at com.google.common.base.Preconditions.checkState(Preconditions.java:754)3 at org.openqa.selenium.remote.service.DriverService.findExecutable(DriverService.java:124)4 at org.openqa.selenium.firefox.GeckoDriverService.access$100(GeckoDriverService.java:41)5 at org.openqa.selenium.firefox.GeckoDriverService$Builder.findDefaultExecutable(GeckoDriverService.java:141)6 at org.openqa.selenium.remote.service.DriverService$Builder.build(DriverService.java:339)7 at org.openqa.selenium.firefox.FirefoxDriver.toExecutor(FirefoxDriver.java:158)8 at org.openqa.selenium.firefox.FirefoxDriver.(FirefoxDriver.java:120)9 at org.openqa.selenium.firefox.FirefoxDriver.(FirefoxDriver.java:98)…………

部分源码如下：

@Testpublic void setUp() throwsException {try{
driver= newFirefoxDriver();
driver.get("https://www.baidu.com/");
System.out.print(driver.getTitle());
driver.quit();
}catch(Exception e) {//TODO Auto-generated catch block
e.printStackTrace();
}
}

2.解决方法如下：

根据报错提示意为，缺少驱动。

(1)根据提示链接：https://github.com/mozilla/geckodriver/releases

下载最新驱动

火狐浏览器支持java插件下载地址 火狐浏览器java不能激活_firefox

(2)解压下载文件，把解压后的文件放入firefox.exe的同目录，默认为 C:\Program Files (x86)\Mozilla Firefox

(3)在源码中的加入

System.setProperty("webdriver.firefox.marionette",
"C:\\Program Files (x86)\\Mozilla Firefox\\geckodriver.exe")；

如下：

1 @Test2 public void setUp() throwsException {3
4 try{5 System.setProperty("webdriver.firefox.marionette",
6 "C:\\Program Files (x86)\\Mozilla Firefox\\geckodriver.exe");
7 driver = newFirefoxDriver();8 driver.get("https://www.baidu.com/");9 System.out.print(driver.getTitle());10 driver.quit();11 } catch(Exception e) {12 //TODO Auto-generated catch block
13 e.printStackTrace();14 }15 }

3.ok，解决了！(其他问题待补充)