Question

我的代码是：

package ant;

import java.util.concurrent.TimeUnit;
import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.openqa.selenium.interactions.Actions;
import org.testng.annotations.Test;
import org.testng.annotations.BeforeMethod;

public class NewTestNG {
    public WebDriver driver; 

    @BeforeMethod
    public void LAunchbrowser() {
        WebDriver driver = new FirefoxDriver();
        driver.get("https://www.google.co.in/");
        driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);
    }

    @Test
    public void main() {
        Actions action = new Actions(driver);
        WebElement a=   driver.findElement(By.xpath(".//*[@id='gs_htif0']"));
        action.moveToElement(a).click().sendKeys("Shirt").build().perform();    
        driver.findElement(By.xpath("//div[@value='Search']")).click();
    }
}

我得到NullPointerException：

FAILED: main

    java.lang.NullPointerException
    at org.openqa.selenium.interactions.Actions.<init>(Actions.java:44)
    at ant.NewTestNG.main(NewTestNG.java:25)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:108)
    at org.testng.internal.Invoker.invokeMethod(Invoker.java:661)
    at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:869)
    at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1193)
    at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:126)
    at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:109)
    at org.testng.TestRunner.privateRun(TestRunner.java:744)
    at org.testng.TestRunner.run(TestRunner.java:602)
    at org.testng.SuiteRunner.runTest(SuiteRunner.java:380)
    at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:375)
    at org.testng.SuiteRunner.privateRun(SuiteRunner.java:340)
    at org.testng.SuiteRunner.run(SuiteRunner.java:289)
    at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
    at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
    at org.testng.TestNG.runSuitesSequentially(TestNG.java:1301)
    at org.testng.TestNG.runSuitesLocally(TestNG.java:1226)
    at org.testng.TestNG.runSuites(TestNG.java:1144)
    at org.testng.TestNG.run(TestNG.java:1115)
    at org.testng.remote.AbstractRemoteTestNG.run(AbstractRemoteTestNG.java:132)
    at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:230)
    at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:76)


===============================================
    Default test
    Tests run: 1, Failures: 1, Skips: 0
===============================================


===============================================
Default suite
Total tests run: 1, Failures: 1, Skips: 0
===============================================

我的代码出了什么问题？

Answer 1

在LaunchBrowser()中，您再次声明driver而不是使用类实例。将其更改为

@BeforeMethod
public void LaunchBrowser() {
    driver = new FirefoxDriver();
    driver.get("https://www.google.co.in/");
    driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);
}

它应该有效。问题是，当您在driver中声明LaunchBrowser()时，该变量的范围仅在方法内部，因此类变量driver不会被使用。因此，当您在方法之外并尝试引用driver时，它会null ...因此例外。

您真的需要花些时间学习如何调试自己的程序。如果你在脚本的开头加上一个断点并逐步完成它，你应该能够自己找到它。

TestNG中的空指针异常

1 个答案: