IntelliJエラー：java.lang.NullPointerException

Question

私はセレニウム、WebDriver、Intellij、Junit4、ChromeDriver、PageObject、PageFactoryを使用します。

私はここの指示に従っています： https://www.youtube.com/watch?v=pO5Ry_GLC60&t=582s このビデオに従うと、プロジェクトが動作します。 ビデオの後にPageFactoryを使用しました。 私はBasePageクラスを記述したAbstractクラスではなく、@ Before、@ After、webdriverのメソッドを含む新しいクラスを作成しました。 テストエラーを実行すると、java.lang.NullPointerEkceptionが発生します。 問題を解決する方法がわかりません。 お願いします。

これは私のホームページのページです：

package PageObjectPage; 


import org.openqa.selenium.By; 
import org.openqa.selenium.WebDriver; 
import org.openqa.selenium.WebElement; 
import org.openqa.selenium.support.CacheLookup; 
import org.openqa.selenium.support.FindBy; 
import org.openqa.selenium.support.How; 
import org.openqa.selenium.support.PageFactory; 

public class HomePage extends BasePage { 

    @FindBy(how = How.NAME, using = "account_icon") 
    @CacheLookup 
    WebElement button_my_accout; 


    public HomePage(WebDriver driver){ 

     super(driver); 
    } 

    public MyAccount clickOnMyAccount(){ 
     //Click on My Account 
     button_my_accout.click(); 

     return PageFactory.initElements(getDriver(), MyAccount.class); 
    } 

    } 

This is MyAccount page: 

package PageObjectPage; 

import org.openqa.selenium.By; 
import org.openqa.selenium.WebDriver; 
import org.openqa.selenium.WebElement; 
import org.openqa.selenium.support.CacheLookup; 
import org.openqa.selenium.support.FindBy; 
import org.openqa.selenium.support.How; 


public class MyAccount extends BasePage { 

    @FindBy(id = "log") 
    @CacheLookup 
    WebElement username; 

    @FindBy(how = How.ID, using = "pwd") 
    @CacheLookup 
    WebElement password; 

    @FindBy(how = How.ID, using = "login") 
    @CacheLookup 
    WebElement login_button; 


    public MyAccount(WebDriver driver){ 

     super(driver); 
    } 

    public MyAccount LogIn(){ 
     //Fill in the text box username 
     username.sendKeys("Dragana"); 
     //Fill in the text box password 
     password.sendKeys("123456"); 

     return new MyAccount(driver); 
    } 
    public LogInResultPage submitForm() { 
     //Click on button Log in 
     login_button.click(); 

     return new LogInResultPage(driver); 
    } 
} 

これはLogInResultPageです：

package PageObjectPage; 

import org.openqa.selenium.By; 
import org.openqa.selenium.WebDriver; 


public class LogInResultPage extends BasePage{ 

    public LogInResultPage(WebDriver driver){ 

     super(driver); 
    } 
    public String getMessage(){ 
     //Printing message 
     return driver.findElement(By.tagName("p")).getText(); 

    } 

} 

これはBasePageクラスのページです：

package PageObjectPage; 


import org.openqa.selenium.WebDriver; 

public class BasePage { 

    protected WebDriver driver; 

    public BasePage (WebDriver driver){ 
     this.driver = driver; 
    } 

    public WebDriver getDriver() { 
     return this.driver; 
    } 

    } 

これはTestBaseページです：

package TestBaseSetup; 

import org.junit.After; 
import org.junit.Before; 
import org.openqa.selenium.WebDriver; 
import org.openqa.selenium.chrome.ChromeDriver; 
import org.openqa.selenium.chrome.ChromeOptions; 


public class TestBase { 

    WebDriver driver; 

    public WebDriver getDriver() { 

     return driver; 
    } 

    @Before 
    public void testSetUp(){ 
     System.setProperty("webdriver.chrome.driver", "C:\\Users\\Dragana\\Desktop\\chromedriver.exe "); 

     ChromeOptions options = new ChromeOptions(); 
     options.addArguments("--start-maximized", "--disable-cache"); 
     driver = new ChromeDriver(options); 

     driver.navigate().to("http://store.demoqa.com/"); 
    } 

    @After 
    public void testTearDown(){ 

     driver.close(); 
    } 

} 

これは私のテストページです：

package test; 

import PageObjectPage.HomePage; 
import PageObjectPage.LogInResultPage; 
import PageObjectPage.MyAccount; 
import TestBaseSetup.TestBase; 
import org.junit.Assert; 
import org.junit.Test; 
import org.openqa.selenium.WebDriver; 


public class AccountTest extends TestBase { 

    public WebDriver getDriver() { 

     return driver; 
    } 

    WebDriver driver; 

    @Test 
    public void shouldLogIn() { 

     HomePage onHomePage = PageFactory.initElements(driver, HomePage.class); 
     System.out.println("Step 1 "); 
     MyAccount onMyAccount = onHomePage.clickOnMyAccount(); 
     System.out.println("Step 2"); 
     LogInResultPage onResultPage = onMyAccount.LogIn().submitForm(); 
     System.out.println("Step 3"); 
     wait(2000); 
     Assert.assertTrue(onResultPage.getMessage().contains("ERROR")); 
    } 

    public void wait(int seconds){ 
     try { 
      Thread.sleep(2000); 
     } catch (final InterruptedException e) { 
      e.printStackTrace(); 
     } 
    } 
} 

エラー：

java.lang.NullPointerException 
    at org.openqa.selenium.support.pagefactory.DefaultElementLocator.findElement(DefaultElementLocator.java:69) 
    at org.openqa.selenium.support.pagefactory.internal.LocatingElementHandler.invoke(LocatingElementHandler.java:38) 
    at com.sun.proxy.$Proxy8.click(Unknown Source) 
    at PageObjectPage.HomePage.clickOnMyAccount(HomePage.java:26) 
    at test.AccountTest.shouldLogIn(AccountTest.java:31) 
    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.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50) 
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) 
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47) 
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) 
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26) 
    at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27) 
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325) 
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78) 
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57) 
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290) 
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71) 
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288) 
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58) 
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268) 
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363) 
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137) 
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:117) 
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:42) 
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:262) 
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:84) 
    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 com.intellij.rt.execution.application.AppMain.main(AppMain.java:147) 

Answer 1

1 .Delete：それはTestBaseからwebdriverをより優先されますbeacuse AccountTestから

public WebDriver getDriver() { 

    return driver; 
} 

WebDriver driver; 

。

1. webdriverをドライバがAccountTest例えばにおけるTestBase

protected WebDriver driver;

OR getDriverを（使用）で保護してくださいHomePage onHomePage = PageFactory.initElements(getDriver(), HomePage.class);