Java – Getting java.lang.NullPointerException for selenium webdriver class

javanullpointerexceptionseleniumselenium-webdrivertestng

I am quite new to Selenium WebDriver. A java.lang.NullPointerException has been troubling me for sometime now, and I cannot understand why. Following are my classes which are quite simple actually:

suiteBase.java

package utilities.suiteBase;

import org.openqa.selenium.WebDriver;

import actions.testPage1.testPage1Actions;
import ui_map.testPage1.TestPage1UI;

public class suiteBase {
    public WebDriver driver;

    protected static TestPage1UI tpui = new TestPage1UI();
    protected static testPage1Actions tpa = new testPage1Actions();
}

testPage1Actions.java

package actions.testPage1;

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

import utilities.suiteBase.suiteBase;

public class testPage1Actions extends suiteBase {

    public WebDriver driver;
    public void test(WebDriver driver){
        WebElement loc1 = driver.findElement(By.xpath("id('email')"));
        loc1.sendKeys("testing");
        System.out.println("done...");  
    }    
}

TestPage1.java

package testPage1;

import org.openqa.selenium.WebDriver;
import org.testng.annotations.Parameters;
import org.testng.annotations.Test;

import utilities.suiteBase.BrowserOpen;

import utilities.suiteBase.suiteBase;

public class TestPage1 extends suiteBase{
    public WebDriver driver;
    BrowserOpen browse = new BrowserOpen();

    @Parameters({ "browserType", "appURL" })
    @Test(priority = 1)
    public void openBrowser(String browserType,  String appURL){
        browse.setUp(browserType, appURL);  
        System.out.println("Done....");
    }

    @Test(priority = 2)
    public void testCase1() throws InterruptedException{
        driver.wait(1000);
        tpa.test(driver);           
    }
}

I run the TestPage1.java file using XML, where I encounter following error:

java.lang.NullPointerException at
testPage1.TestPage1.testCase1(TestPage1.java:28) 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:497) at
org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:80)
at org.testng.internal.Invoker.invokeMethod(Invoker.java:714) 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:126)
at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:137)
at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:58)

Also I have browserOpen class which I run before TestPage1, in which I declare the WebDriver

package utilities.suiteBase;

import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.testng.annotations.AfterClass;
import org.testng.annotations.BeforeClass;
import org.testng.annotations.Parameters;
import org.testng.annotations.Test;

import utilities.suiteBase.BrowserOpen;

public class BrowserOpen {

    public WebDriver driver;
    static String driverPath = "E:\\Selenium\\";

    public void setUp(String browserType, String appURL) {
        try {
            setDriver(browserType, appURL);

        } catch (Exception e) {
            System.out.println("Error....." + e.getStackTrace());
        }
    }

    @AfterClass
    public void tearDown() {
        driver.quit();
    }

private void setDriver(String browserType, String appURL) {
    switch (browserType) {
    case "chrome":
        driver = initChromeDriver(appURL);
        break;
    case "firefox":
        driver = initFirefoxDriver(appURL);
        break;
    default:
        System.out.println("browser : " + browserType
                + " is invalid, Launching Firefox as browser of choice..");
        driver = initFirefoxDriver(appURL);
    }
}

private static WebDriver initChromeDriver(String appURL) {
    System.out.println("Launching google chrome with new profile..");
    System.setProperty("webdriver.chrome.driver", driverPath + "chromedriver.exe");
    WebDriver driver = new ChromeDriver();
    driver.manage().window().maximize();
    driver.navigate().to(appURL);
    System.out.println("URL inserted");
//  driver.get(appURL);
    return driver;
}

private static WebDriver initFirefoxDriver(String appURL) {
    System.out.println("Launching Firefox browser..");
    WebDriver driver = new FirefoxDriver();
    driver.manage().window().maximize();
    driver.navigate().to(appURL);
    return driver;
}
}

Best Answer

I never used this technology before, but I see not inited elements.

public WebDriver driver;

WebDriver was not initialized.
You need to initialize them before using. Like:

WebDriver driver = new FirefoxDriver();

Or something else. Check this out: http://www.seleniumhq.org/docs/03_webdriver.jsp

-- UPD: Exception is probably throwing at testCase1() tpa.test(WebDriver). tpa is probably null.

Related Solutions

Selenium – null pointer exception_using java selenium webdriver with TestNG

This isn't hard to explain. The default constructor of your test class MainHerokuapp will be called as soon as it is run, i.e. when driver is still null - before your @BeforeTest method, where driver gets set.

MainHerokuapp and TestBase seem to be mixed-up rather than having a clear separation, so you'd be better off merging them back into one.

Another way is to restore control to the child class by dropping the constructor, moving the @BeforeTest there, and calling up to the parent. This definitely works:

public class MainHerokuapp extends TestBase {
    Pom_MainHerokuapp mainHerokuappObject;

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    public void setup() {
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        mainHerokuappObject = new Pom_MainHerokuapp(driver);
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    @Test(priority = 0)
    public void TestMainpagetitle() {
        mainHerokuappObject.VerifyTitles();
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    @Test(priority = 1)
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        mainHerokuappObject.VerifyTextOfABTesting();
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public class TestBase {
    public WebDriver driver;

    // @BeforeTest
    public void setup() {
        driver = new FirefoxDriver();
        driver.get("https://the-internet.herokuapp.com/");
        driver.manage().window().maximize();
        driver.manage().timeouts().implicitlyWait(30, TimeUnit.SECONDS);
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Java – Data provider mismatch in Selenium with TestNG

The only problem I see is this, You are reading from excel so may be all the values are coming in String, unless you are converting that to Integer. However, in your test you expect third argument age to be Integer

Changing type to String should resolve the issue

@Test(dataProvider = "newdata")
public void testData(String username, String password, String age) {
        System.out.println(username + " - " + password + " - " + age);
}

The following code would raise the same error.

@DataProvider(name = "newdata")
public static Object[][] getData() {
    return new Object[][]{
            {"20"},
            {"30"}
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}

@Test(dataProvider = "newdata")
public void testData(Integer age) {

    System.out.println(age);

}