NullPointerException in Selenium WebDriver using TestNg and Maven - eclipse

Question

I am currently building a Maven Project which also includes the TestNg Library within Eclipse. I am running on Java 8 (having switched from Java 9 as I've heard this has caused issues with others) using the latest Selenium release, 3.8.1. My project was working smoothly with no issues, tests were running great and then it began to throw NullPointerExceptions. I have tried building the project again to no avail.
Here is my set up:
Here is the TestBase class where I use #BeforeSuite and #AfterSuite to instantiate WebDriver. This launches with no issues.
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Properties;
import org.apache.log4j.Logger;
import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.openqa.selenium.ie.InternetExplorerDriver;
import org.openqa.selenium.remote.DesiredCapabilities;
import org.testng.annotations.AfterSuite;
import org.testng.annotations.BeforeSuite;
public class TestBaseMaven {
public WebDriver driver;
public static FileInputStream fis;
public static FileInputStream fis1;
public static Properties config = new Properties();
public static Properties OR = new Properties();
public static Logger log;
#BeforeSuite
public void setUp() throws IOException, InterruptedException {
fis = new FileInputStream("C:\\Users\\Kohout\\eclipse-workspace\\MavenProjects\\MavenProject2\\src\\test\\resources\\properties\\Config.properties");
config.load(fis);
fis1 = new FileInputStream("C:\\Users\\Kohout\\eclipse-workspace\\MavenProjects\\MavenProject2\\src\\test\\resources\\properties\\OR.properties");
OR.load(fis1);
if(driver==null) {
if(config.getProperty("browser").equals("chrome")) {
System.setProperty("webdriver.chrome.driver", "C:\\Users\\Kohout\\eclipse-workspace\\MavenProjects\\MavenProject2\\src\\test\\resources\\executables\\chromedriver.exe");
driver = new ChromeDriver();
} else if(config.getProperty("browser").equals("firefox")) {
System.setProperty("webdriver.gecko.driver", "C:\\Users\\Kohout\\eclipse-workspace\\MavenProjects\\MavenProject2\\src\\test\\resources\\executables\\geckodriver.exe");
DesiredCapabilities dc = DesiredCapabilities.firefox();
dc.setCapability("marionette", true);
driver=new FirefoxDriver();
} else if(config.getProperty("browser").equals("ie")) {
System.setProperty("webdriver.ie.driver", "C:\\Users\\Kohout\\eclipse-workspace\\MavenProjects\\MavenProject2\\src\\test\\resources\\executables\\IEDriverServer.exe");
driver = new InternetExplorerDriver();
}
}
driver.get(config.getProperty("testUrl"));
driver.manage().window().maximize();
Thread.sleep(2000);
}
public boolean isElementPresent(By by) {
try {
driver.findElement(by);
return true;
} catch(Throwable t) {
return false;
}
}
#AfterSuite
public void tearDown() {
if(driver!=null) {
driver.quit();
}
}
}
Here is my first Test, which also runs fine and is passing. Though at times this will also throw a NullPointerException where I use Webdriver, such as in driver.findElement...
import org.openqa.selenium.By;
import org.testng.Assert;
import org.testng.annotations.Test;
import com.kohout.base.TestBaseMaven;
public class ManagerLoginTest extends TestBaseMaven {
#Test
public void managerLoginTest() throws InterruptedException {
driver.findElement(By.cssSelector(config.getProperty("managerLogin"))).click();
Thread.sleep(2000);
Assert.assertTrue(isElementPresent(By.cssSelector(OR.getProperty("addCust"))));
}
}
Here is my second Test. Now for whatever reason, this one ALWAYS throws a NullPointerException whenever I use my instantiated driver variable (instantiated in #BeforeSuite).
import org.openqa.selenium.By;
import org.openqa.selenium.WebElement;
import org.testng.annotations.Test;
import com.kohout.base.TestBaseMaven;
public class AddCustomerTest extends TestBaseMaven {
#Test
public void addCustomerTest() {
driver.findElement(By.xpath("/html/body/div[3]/div/div[2]/div/div[1]/button[1]"));
}
}
Here is my stack trace:
java.lang.NullPointerException
at com.kohout.testcases.AddCustomerTest.addCustomerTest(AddCustomerTest.java:14)
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:124)
at org.testng.internal.Invoker.invokeMethod(Invoker.java:571)
at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:707)
at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:979)
at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:125)
at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:109)
at org.testng.TestRunner.privateRun(TestRunner.java:648)
at org.testng.TestRunner.run(TestRunner.java:505)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:455)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:450)
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:415)
at org.testng.SuiteRunner.run(SuiteRunner.java:364)
at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:84)
at org.testng.TestNG.runSuitesSequentially(TestNG.java:1187)
at org.testng.TestNG.runSuitesLocally(TestNG.java:1116)
at org.testng.TestNG.runSuites(TestNG.java:1028)
at org.testng.TestNG.run(TestNG.java:996)
at org.testng.remote.AbstractRemoteTestNG.run(AbstractRemoteTestNG.java:114)
at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:251)
at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:77)
I also want to include my testng.xml, which I am also calling in my pom.xml:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE suite SYSTEM "http://testng.org/testng-1.0.dtd">
<suite name="Bank Suite">
<test name="Login Test">
<classes>
<class name="com.kohout.testcases.ManagerLoginTest"/>
<class name="com.kohout.testcases.AddCustomerTest"/>
</classes>
</test> <!-- Test -->
</suite> <!-- Suite -->
Here is my POM.xml too:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.kohout</groupId>
<artifactId>MavenProject2</artifactId>
<version>0.0.1-SNAPSHOT</version>
<dependencies>
<!-- https://mvnrepository.com/artifact/org.seleniumhq.selenium/selenium-java -->
<dependency>
<groupId>org.seleniumhq.selenium</groupId>
<artifactId>selenium-java</artifactId>
<version>3.8.1</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.testng/testng -->
<dependency>
<groupId>org.testng</groupId>
<artifactId>testng</artifactId>
<version>6.13.1</version>
<scope>test</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.poi/poi -->
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>3.6</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.poi/poi-ooxml -->
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>3.6</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.poi/poi-ooxml-schemas -->
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml-schemas</artifactId>
<version>3.6</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.xmlbeans/xmlbeans -->
<dependency>
<groupId>org.apache.xmlbeans</groupId>
<artifactId>xmlbeans</artifactId>
<version>2.6.0</version>
</dependency>
</dependencies>
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.20.1</version>
<configuration>
<suiteXmlFiles>
<suitXmlFile>C:\Users\Kohout\eclipse-workspace\MavenProjects\MavenProject2\testng.xml</suitXmlFile>
</suiteXmlFiles>
</configuration>
</plugin>
</plugins>
</pluginManagement>
</build>
</project>
Thank you for the time and the help.

Answer 1

The problem is in your test code. You are making use of a #BeforeSuite annotation in your base class to initialise the WebDriver instance.
TestNG executes a #BeforeSuite annotated method only once per <suite> tag.
Both your test classes have the same base class and so the initialising method setUp() is called only for your test class com.kohout.testcases.ManagerLoginTest and it wont get called for com.kohout.testcases.AddCustomerTest.
Please change it to start using #BeforeClass (or) #BeforeMethod annotation if your test class has exactly just one #Test method.
If your test classes have more than one #Test methods, then you should basically make use of a ThreadLocal variant (or) you should make use of a TestNG listener to initialise the webdriver and then query the webdriver instance.
You can refer to my blog post here to learn how to work with TestNG listeners to facilitate parallel execution.
Here's a sample that shows how the thread local variant would look like
import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.openqa.selenium.ie.InternetExplorerDriver;
import org.openqa.selenium.remote.DesiredCapabilities;
import org.testng.annotations.AfterMethod;
import org.testng.annotations.BeforeMethod;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Properties;
import java.util.logging.Logger;
public class TestBaseMavenRefactored {
private static final String PREFIX = "C:\\Users\\Kohout\\eclipse-workspace\\MavenProjects\\MavenProject2";
private static final ThreadLocal<WebDriver> driver = new ThreadLocal<>();
private Properties config = new Properties();
private Properties OR = new Properties();
public static Logger log;
protected WebDriver getDriver() {
return driver.get();
}
protected Properties getConfig() {
return config;
}
public Properties getOR() {
return OR;
}
private void cleanupDriver() {
driver.get().quit();
driver.remove();
}
#BeforeMethod
public void setUp() throws IOException, InterruptedException {
FileInputStream fis = new FileInputStream(PREFIX + "\\src\\test\\resources\\properties\\Config.properties");
config.load(fis);
FileInputStream fis1 = new FileInputStream(PREFIX + "\\src\\test\\resources\\properties\\OR.properties");
OR.load(fis1);
switch (config.getProperty("browser")) {
case "chrome":
System.setProperty("webdriver.chrome.driver", PREFIX + "\\src\\test\\resources\\executables\\chromedriver.exe");
driver.set(new ChromeDriver());
break;
case "firefox":
System.setProperty("webdriver.gecko.driver", PREFIX + "\\src\\test\\resources\\executables\\geckodriver.exe");
DesiredCapabilities dc = DesiredCapabilities.firefox();
dc.setCapability("marionette", true);
driver.set(new FirefoxDriver());
break;
case "ie":
System.setProperty("webdriver.ie.driver", PREFIX + "\\src\\test\\resources\\executables\\IEDriverServer.exe");
driver.set(new InternetExplorerDriver());
break;
}
getDriver().get(config.getProperty("testUrl"));
getDriver().manage().window().maximize();
Thread.sleep(2000);
}
public boolean isElementPresent(By by) {
try {
getDriver().findElement(by);
return true;
} catch (Throwable t) {
return false;
}
}
#AfterMethod
public void tearDown() {
cleanupDriver();
}
}
Here's how the refactored test class would now look like :
import org.openqa.selenium.By;
import org.testng.Assert;
import org.testng.annotations.Test;
public class ManagerLoginTest extends TestBaseMavenRefactored {
#Test
public void managerLoginTest() throws InterruptedException {
getDriver().findElement(By.cssSelector(getConfig().getProperty("managerLogin"))).click();
Thread.sleep(2000);
Assert.assertTrue(isElementPresent(By.cssSelector(getOR().getProperty("addCust"))));
}
}