如何在selenium-java中调试NullPointerException

Question

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FAILED CONFIGURATION: @BeforeMethod setUp
java.lang.NullPointerException
    at com.ecinteractive.base.TestBase.initialization(TestBase.java:50)
    at com.ecinteractive.testcases.LoginPageTest.setUp(LoginPageTest.java:32)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:80)
    at org.testng.internal.Invoker.invokeConfigurationMethod(Invoker.java:564)
    at org.testng.internal.Invoker.invokeConfigurations(Invoker.java:213)
    at org.testng.internal.Invoker.invokeMethod(Invoker.java:653)
    at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:901)
    at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1231)
    at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:127)
    at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:111)
    at org.testng.TestRunner.privateRun(TestRunner.java:767)
    at org.testng.TestRunner.run(TestRunner.java:617)
    at org.testng.SuiteRunner.runTest(SuiteRunner.java:334)
    at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:329)
    at org.testng.SuiteRunner.privateRun(SuiteRunner.java:291)
    at org.testng.SuiteRunner.run(SuiteRunner.java:240)
    at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
    at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
    at org.testng.TestNG.runSuitesSequentially(TestNG.java:1198)
    at org.testng.TestNG.runSuitesLocally(TestNG.java:1123)
    at org.testng.TestNG.run(TestNG.java:1031)
    at org.testng.remote.AbstractRemoteTestNG.run(AbstractRemoteTestNG.java:115)
    at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:251)
    at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:77)

SKIPPED CONFIGURATION: @AfterMethod tearDown
SKIPPED CONFIGURATION: @BeforeMethod setUp
SKIPPED CONFIGURATION: @AfterMethod tearDown
SKIPPED CONFIGURATION: @BeforeMethod setUp
SKIPPED CONFIGURATION: @AfterMethod tearDown
SKIPPED: loginPageTitleTest
SKIPPED: logoImageTest
SKIPPED: loginTest

===============================================
    Default test
    Tests run: 3, Failures: 0, Skips: 3
    Configuration Failures: 1, Skips: 5
===============================================


===============================================
Default suite
Total tests run: 3, Failures: 0, Skips: 3
Configuration Failures: 1, Skips: 5
===============================================

[TestNG] Time taken by org.testng.reporters.EmailableReporter@2d127a61: 0 ms
[TestNG] Time taken by org.testng.reporters.XMLReporter@290dbf45: 16 ms
[TestNG] Time taken by [FailedReporter passed=0 failed=0 skipped=0]: 15 ms
[TestNG] Time taken by org.testng.reporters.JUnitReportReporter@4e41089d: 0 ms
[TestNG] Time taken by org.testng.reporters.SuiteHTMLReporter@7181ae3f: 32 ms
[TestNG] Time taken by org.testng.reporters.jq.Main@4e4aea35: 31 ms

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

<#>LoginPageTest类

package com.ecinteractive.testcases;

import org.testng.Assert;
import org.testng.annotations.AfterClass;
import org.testng.annotations.AfterMethod;
import org.testng.annotations.AfterTest;
import org.testng.annotations.BeforeClass;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.BeforeTest;
import org.testng.annotations.Test;

import com.ecinteractive.base.TestBase;
import com.ecinteractive.pages.HomePage;
import com.ecinteractive.pages.LoginPage;

public class LoginPageTest extends TestBase {
    LoginPage loginPage;
    HomePage homePage;



    public LoginPageTest() {
        super();


    }

    @BeforeMethod

    public void setUp() {
        initialization();
        this.loginPage = new LoginPage();


    }

@Test (priority=1)
public void loginPageTitleTest() {
    String title = loginPage.validateLoginPageTitle();
    Assert.assertEquals(title, "Login | ECi - QA Site 1");

}
@Test(priority=2)
public void logoImageTest() {
    boolean flag =loginPage.validateLogo() ;
    Assert.assertTrue(flag);

}

@Test(priority=3)
public void loginTest() {
    homePage= loginPage.login(prop.getProperty("username"), prop.getProperty("password"));

}






@AfterMethod

public void tearDown() {
    driver.quit();

}
}
+++++++++++++++++++++++++++++++++++++++++++++++++++

Test基类

package com.ecinteractive.base;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Properties;
import java.util.concurrent.TimeUnit;

import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.firefox.FirefoxDriver;

import com.ecinteractive.util.TestUtil;

public class TestBase {

    public static WebDriver driver;
    public static Properties prop;

    public TestBase() {

        try {

            prop = new Properties();
            FileInputStream ip = new FileInputStream(
                    System.getProperty("user.dir") + "/src/main/java/com/ecinteractive" + "/config/config.properties");
            prop.load(ip);

        } catch (FileNotFoundException e) {
            e.printStackTrace();

        } catch (IOException e) {
            e.printStackTrace();
        }

    }

    public static void initialization() {
        String browserName = prop.getProperty("browser");

        if (browserName.equals("chrome")) {
            System.setProperty("webdriver.chrome.driver", "/Drivers/chromedriver.exe");
            driver = new ChromeDriver();

        } else if (browserName.equals("FF")) {
            System.setProperty("webdriver.gecko.driver", "/Drivers/geckodriver.exe");
            driver = new FirefoxDriver();

        }
        driver.manage().window().maximize();
        driver.manage().deleteAllCookies();
        driver.manage().timeouts().pageLoadTimeout(TestUtil.PAGE_LOAD_TIMEOUT, TimeUnit.SECONDS);
        driver.manage().timeouts().implicitlyWait(TestUtil.PAGE_LOAD_TIMEOUT, TimeUnit.SECONDS);

        driver.get(prop.getProperty("url"));

}
}
++++++++++++++++++++++++++++

属性

url =

用户名=密码=

browser =铬

LoginPage.java

package com.ecinteractive.pages;

import org.openqa.selenium.WebElement;
import org.openqa.selenium.support.FindBy;
import org.openqa.selenium.support.PageFactory;

import com.ecinteractive.base.TestBase;

public class LoginPage extends TestBase {

    //Page Factory -OR

    @FindBy(id="UserName")
    WebElement UserName;


    @FindBy(id="Request_Password")
    WebElement Request_Password;

    @FindBy(xpath="//span[contains(text(),'Login')]")
    WebElement loginBtn;

    @FindBy(xpath="//div[@class='logo']")
    WebElement logo;


    //Now we need to initialize all the OR so we create a Constructor
    // this is current class 

    public LoginPage() {
        PageFactory.initElements(driver, this);

    }

    //Actions
    public String validateLoginPageTitle () {
        return driver.getTitle();

    }
    public boolean validateLogo() {
        return logo.isDisplayed();      
    }
    public HomePage login(String un, String pwd) {
        UserName.sendKeys(un);
        Request_Password.sendKeys(pwd);
        loginBtn.click();


        return new HomePage();

    }
}

Answer 1

所显示的例外是：

FAILED CONFIGURATION: @BeforeMethod setUp
java.lang.NullPointerException
    at com.ecinteractive.base.TestBase.initialization(TestBase.java:50)

因此，在(TestBase.java:50)中，可以说异常是在TestBase类的line 50处抛出的。

在分析TestBase的第50行时，我们可以看到抛出错误的代码如下：

driver.manage().window().maximize();

这表明驱动程序对象未正确初始化，

<#>so试图打印browserName并查看您是否实际获得了所需的值，因为代码似乎没有输入任何if语句。

我硬编码了值browsername="chrome“，一切都很好。所以看起来prop.getproperty(“浏览器”)没有给出铬，试着在if语句之前打印它。确保没有空格或字符

并查看是否有任何尾随或前导空格fpr browserName值。在比较之前删除它，或者使用browserName.contains("chrome")代替browserName.equals("chrome")