出现 java.lang.NullPointerException

Question

我是自动化领域的新手。这是我的简单 TestNG 登录代码，当我以 TestNG 身份运行该代码时，它会出现 java.lang.NullPointerException，双击它会突出显示我导航到 URL 的位置。这是我的代码。

enter code here

package Day5pkg;

import java.util.concurrent.TimeUnit;

import org.openqa.selenium.By;

import org.openqa.selenium.WebDriver;

import org.openqa.selenium.firefox.FirefoxDriver;

import org.openqa.selenium.firefox.FirefoxDriver;

import org.openqa.selenium.firefox.FirefoxOptions;

import org.testng.annotations.AfterMethod;

import org.testng.annotations.BeforeTest;

import org.testng.annotations.Test;

public class Day5 {

    public WebDriver driver;

@BeforeTest

      public void beforeTest() {

          System.setProperty("webdriver.firefox.driver","C:\\Users\\Nabila\\Downloads\\geckodriver-v0.26.0-win64\\geckodriver.exe");

          FirefoxOptions options = new FirefoxOptions();

            driver.navigate().to("http://www.demo.guru99.com/V4/");

            driver.manage().timeouts().implicitlyWait(300, TimeUnit.SECONDS);

            options.addArguments("test-type");

            options.addArguments("start-maximized");

            options.addArguments("--js-flags=--expose-gc");  

            options.addArguments("--enable-precise-memory-info"); 

            options.addArguments("--disable-popup-blocking");

            options.addArguments("--disable-default-apps");

            options.addArguments("test-type=browser");

            options.addArguments("disable-infobars");

      }

  @Test  (priority = 0)

    public void login(){

      driver = new FirefoxDriver();

         driver.findElement(By.name("uid")).sendKeys("mngr231");

         driver.findElement(By.name("password")).click();

         driver.findElement(By.name("password")).sendKeys("ehyjusu");

         driver.findElement(By.name("btnLogin")).click();

            System.out.println("Manger Id : mngr230");

      }

Answer 1

您仅将WebDriver实例声明为：public WebDriver driver;您还需要对其进行初始化，如下所示：driver = new FirefoxDriver();您的有效代码块的实例FirefoxOptions()将是：System.setProperty("webdriver.firefox.driver","C:\\Users\\Nabila\\Downloads\\geckodriver-v0.26.0-win64\\geckodriver.exe");FirefoxOptions options = new FirefoxOptions();options.addArguments("test-type");options.addArguments("start-maximized");options.addArguments("--js-flags=--expose-gc");  options.addArguments("--enable-precise-memory-info"); options.addArguments("--disable-popup-blocking");options.addArguments("--disable-default-apps");options.addArguments("test-type=browser");options.addArguments("disable-infobars");driver = new FirefoxDriver(options);driver.navigate().to("http://www.demo.guru99.com/V4/");driver.manage().timeouts().implicitlyWait(300, TimeUnit.SECONDS);