无法在 selenium webdriver java 中使用 @FindBy 进行初始化

Question

I am trying to perform basic selenium operations using page object pattern. However, when I run the test, I see browser being opened along with given url, but fails the test by complaining it couldn't initialise the declared web element. Can some one please help me to understand what I'm missing here. Below are my base class, page object class and test class.

BasePage

public class Basepage {

public static WebDriver driver;

public Basepage(){}

public Basepage(WebDriver driver){
    this.driver = driver;
    PageFactory.initElements(driver,this);
}

public void OpenBrowser(){
    System.setProperty("webdriver.chrome.driver", 
"C:\\SeleniumWork\\chromedriver_win32\\chromedriver.exe");
    driver = new ChromeDriver();
    driver.navigate().to("https://www.google.com");
}

Page object class

public class SecurityMainPage extends Basepage{

public SecurityMainPage(WebDriver driver){
    this.driver = driver;
    PageFactory.initElements(driver,this);
}

@FindBy( xpath = "//a[text()='What We Do']")
WebElement dropdown;

public void selectOption(String option){
    Actions actions = new Actions(driver);
    actions.moveToElement(dropdown).click().build().perform();  //dropdown element is returning null 
}

TestClass

public class SecurityMainPageTests extends Basepage {

protected static SecurityMainPage sec = new SecurityMainPage(driver);
public SecurityMainPageTests(){}

@BeforeTest
public void setup(){
    OpenBrowser();
}
@Test
public void selectOptionTest(){
    sec.selectOption("Networking");
}
@AfterTest
public void tearDown(){
    closeBrowser();
}

Log

org.openqa.selenium.json.JsonException: java.lang.reflect.InvocationTargetException
Build info: version: '3.13.0', revision: '2f0d292', time: '2018-06-25T15:24:21.231Z'
System info: host: 'LAPTOP-5J2KPMM3', ip: '192.168.0.36', os.name: 'Windows 10', os.arch: 'amd64', os.version: '10.0', java.version: '11.0.7'
Driver info: driver.version: RemoteWebDriver

    at org.openqa.selenium.json.JsonOutput.convertUsingMethod(JsonOutput.java:302)
    at org.openqa.selenium.json.JsonOutput.lambda$new$13(JsonOutput.java:139)
    at org.openqa.selenium.json.JsonOutput$SafeBiConsumer.accept(JsonOutput.java:394)
    at org.openqa.selenium.json.JsonOutput.write(JsonOutput.java:248)
    at org.openqa.selenium.json.JsonOutput.lambda$null$18(JsonOutput.java:152)
    at java.base/java.lang.Iterable.forEach(Iterable.java:75)
    at org.openqa.selenium.json.JsonOutput.lambda$new$19(JsonOutput.java:152)
    at org.openqa.selenium.json.JsonOutput$SafeBiConsumer.accept(JsonOutput.java:394)
    at org.openqa.selenium.json.JsonOutput.write(JsonOutput.java:248)
    at org.openqa.selenium.json.JsonOutput.lambda$null$20(JsonOutput.java:161)
    at com.google.common.collect.SingletonImmutableBiMap.forEach(SingletonImmutableBiMap.java:65)
    at org.openqa.selenium.json.JsonOutput.lambda$new$21(JsonOutput.java:160)
    at org.openqa.selenium.json.JsonOutput$SafeBiConsumer.accept(JsonOutput.java:394)
    at org.openqa.selenium.json.JsonOutput.write(JsonOutput.java:248)
    at org.openqa.selenium.json.JsonOutput.write(JsonOutput.java:239)
    at org.openqa.selenium.json.Json.toJson(Json.java:42)
    at org.openqa.selenium.remote.http.AbstractHttpCommandCodec.encode(AbstractHttpCommandCodec.java:227)
    at org.openqa.selenium.remote.http.AbstractHttpCommandCodec.encode(AbstractHttpCommandCodec.java:117)
    at org.openqa.selenium.remote.HttpCommandExecutor.execute(HttpCommandExecutor.java:152)
    at org.openqa.selenium.remote.service.DriverCommandExecutor.execute(DriverCommandExecutor.java:83)
    at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:548)
    at org.openqa.selenium.remote.RemoteWebDriver.perform(RemoteWebDriver.java:614)
    at org.openqa.selenium.interactions.Actions$BuiltAction.perform(Actions.java:638)
    at test.java.SecurityMainPage.selectOption(SecurityMainPage.java:37)
    at test.java.SecurityMainPageTests.selectOptionTest(SecurityMainPageTests.java:28)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:85)
    at org.testng.internal.Invoker.invokeMethod(Invoker.java:639)
    at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:816)
    at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1124)
    at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:125)
    at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:108)
    at org.testng.TestRunner.privateRun(TestRunner.java:774)
    at org.testng.TestRunner.run(TestRunner.java:624)
    at org.testng.SuiteRunner.runTest(SuiteRunner.java:359)
    at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:354)
    at org.testng.SuiteRunner.privateRun(SuiteRunner.java:312)
    at org.testng.SuiteRunner.run(SuiteRunner.java:261)
    at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
    at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
    at org.testng.TestNG.runSuitesSequentially(TestNG.java:1191)
    at org.testng.TestNG.runSuitesLocally(TestNG.java:1116)
    at org.testng.TestNG.run(TestNG.java:1024)
    at com.intellij.rt.testng.IDEARemoteTestNG.run(IDEARemoteTestNG.java:66)
    at com.intellij.rt.testng.RemoteTestNGStarter.main(RemoteTestNGStarter.java:110)
    Suppressed: org.openqa.selenium.json.JsonException: Attempting to close incomplete json stream
Build info: version: '3.13.0', revision: '2f0d292', time: '2018-06-25T15:24:21.231Z'

Driver info: driver.version: RemoteWebDriver
        at org.openqa.selenium.json.JsonOutput.close(JsonOutput.java:263)
        at org.openqa.selenium.json.Json.toJson(Json.java:44)
        ... 32 more
Caused by: java.lang.reflect.InvocationTargetException
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.openqa.selenium.json.JsonOutput.convertUsingMethod(JsonOutput.java:298)
    ... 47 more
Caused by: 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.$Proxy9.getWrappedElement(Unknown Source)
    at org.openqa.selenium.interactions.PointerInput$Origin.asArg(PointerInput.java:203)
    at org.openqa.selenium.interactions.PointerInput$Move.encode(PointerInput.java:154)
    at org.openqa.selenium.interactions.Sequence.encode(Sequence.java:75)
    at org.openqa.selenium.interactions.Sequence.toJson(Sequence.java:84)
    ... 52 more

Answer 1

For easy understanding, I split the driver initiation and navigation to url to two methods in Basepage . And you haven't declared the closeBrowser() method.

Base Class

public class Basepage {

    public static WebDriver driver;

    public Basepage(){}
 
    public Basepage(WebDriver driver){
        this.driver = driver;
        PageFactory.initElements(driver,this);
    }

    public WebDriver initiateDriver(){
        System.setProperty("webdriver.chrome.driver", 
        "C:\\SeleniumWork\\chromedriver_win32\\chromedriver.exe");
        driver = new ChromeDriver();
        return driver;
    }

    public void openBrowser(String url){
        driver.navigate().to(url);
    }
}

Test Class

public class SecurityMainPageTests extends Basepage {

    WebDriver driver = null;
    protected static SecurityMainPage sec = null;
    String url = "https://www.google.com";

    public SecurityMainPageTests(){}

    @BeforeTest
    public void setup(){
        driver = initiateDriver();
        openBrowser(String url);
        sec = new SecurityMainPage(driver);
    }

    @Test
    public void selectOptionTest(){
        sec.selectOption("Networking");
    }

    @AfterTest
    public void tearDown(){
        closeBrowser();
    }
}