Getting NullPointerException when trying to access Selenium Webdriver instance in below scenario. - selenium

Question

I am trying to create a framework where I can run my test cases(test tags in xml file) in parallel in different browsers. I have tried using all combinations of testNG annotations but after reading a blog came to know that this can only be achieved by using testNg listners. I am using ThreadLocal to keep my driver thread-safe. I am getting null pointer exception when trying to access Webdriver in my test cases class in line LocalDriverManager.getDriver().get(url);
This is LocalBrowserFactory.Class
package BrowserFactory;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.openqa.selenium.ie.InternetExplorerDriver;
import DataProvider.ConfigDataProvider;
public class LocalDriverFactory {
public static WebDriver createInstance(String browserName) {
WebDriver driver = null;
ConfigDataProvider config=new ConfigDataProvider();
if (browserName.toLowerCase().contains("firefox")) {
System.setProperty("webdriver.gecko.driver", config.getgeckoPath());
driver = new FirefoxDriver();
}
if (browserName.toLowerCase().contains("internet")) {
driver = new InternetExplorerDriver();
}
if (browserName.toLowerCase().contains("chrome")) {
System.setProperty("webdriver.chrome.driver", config.getchromePath());
driver = new ChromeDriver();
}
driver.manage().window().maximize();
return driver;
}
}
This is my LocalDriverManager.class
package BrowserFactory;
import org.openqa.selenium.WebDriver;
public class LocalDriverManager {
private static ThreadLocal<WebDriver> webDriver = new ThreadLocal<WebDriver>();
public static WebDriver getDriver() {
return webDriver.get();
}
public static void setWebDriver(WebDriver driver) {
webDriver.set(driver);
}
}
This is my ConfigPropertyReader.class
package DataProvider;
import java.io.File;
import java.io.FileInputStream;
import java.util.Properties;
public class ConfigDataProvider {
static Properties p;
public ConfigDataProvider()
{
File f =new File("C:/Eclipse/parallelframework/configuration/config.properties");
try {
FileInputStream fis = new FileInputStream(f);
p=new Properties();
p.load(fis);
}
catch (Exception e)
{
System.out.println("Custom Exception- cannot load properties file"+e.getMessage());
}
}
public String getvalue(String key)
{
return p.getProperty(key);
}
public String getUrl()
{
return p.getProperty("url");
}
public String getchromePath()
{
return p.getProperty("chromepath");
}
public String getgeckoPath()
{
return p.getProperty("firefoxpath");
}
public String getIEPath()
{
return System.getProperty("User.dir")+p.getProperty("IEPath");
}
}
This is WebDriverListner.class
package Listners;
import org.openqa.selenium.WebDriver;
import org.testng.IInvokedMethod;
import org.testng.IInvokedMethodListener;
import org.testng.ITestResult;
import BrowserFactory.LocalDriverFactory;
import BrowserFactory.LocalDriverManager;
public class WebDriverListner implements IInvokedMethodListener {
public void afterInvocation(IInvokedMethod method, ITestResult testResult) {
if (method.isTestMethod()) {
String browserName = method.getTestMethod().getXmlTest().getLocalParameters().get("browserName");
System.out.println(browserName);
WebDriver driver = LocalDriverFactory.createInstance(browserName);
LocalDriverManager.setWebDriver(driver);
System.out.println("Driver Set");
}
}
public void beforeInvocation(IInvokedMethod method, ITestResult testResult) {
if (method.isTestMethod()) {
WebDriver driver = LocalDriverManager.getDriver();
if (driver != null) {
driver.quit();
}
}
}
}
This is my sample testcase.class
package tests;
import org.openqa.selenium.WebDriver;
import org.testng.annotations.Test;
import BrowserFactory.LocalDriverManager;
public class sampleTest {
#Test
public void testMethod1() {
invokeBrowser("http://www.ndtv.com");
}
#Test
public void testMethod2() {
invokeBrowser("http://www.facebook.com");
}
private void invokeBrowser(String url) {
LocalDriverManager.getDriver().get(url);
}
}

Answer 1

Your Listener code is messed up. You basically have the beforeInvocation and afterInvocation in the wrong order.
Here's how it should have looked like
import org.openqa.selenium.WebDriver;
import org.testng.IInvokedMethod;
import org.testng.IInvokedMethodListener;
import org.testng.ITestResult;
public class WebDriverListener implements IInvokedMethodListener {
#Override
public void beforeInvocation(IInvokedMethod method, ITestResult testResult) {
if (method.isTestMethod()) {
String browserName = method.getTestMethod().getXmlTest().getLocalParameters().get("browserName");
WebDriver driver = LocalDriverFactory.createInstance(browserName);
LocalDriverManager.setWebDriver(driver);
}
}
#Override
public void afterInvocation(IInvokedMethod method, ITestResult testResult) {
if (method.isTestMethod()) {
WebDriver driver = LocalDriverManager.getDriver();
if (driver != null) {
driver.quit();
}
}
}
}
You basically would setup the webdriver into the thread local variable (push the webdriver instance into the thread local variable's context) from within the beforeInvocation and then within your afterInvocation method, you would pop it out and clean up the webdriver instance (by calling quit() ). In your case, your code is doing the opposite.
For more details you can refer to my blog post here.