Null pointer exception while running testng.xml with groups tag

package com.qa.tc;

import java.util.concurrent.TimeUnit;

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;
import org.testng.annotations.AfterMethod;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.Test;

public class GroupTest {
	
		WebDriver driver;

		@BeforeMethod
		public void setUp()
		{
	      System.setProperty("webdriver.chrome.driver", "D:\\Girish\\chromedriver_win32\\chromedriver.exe");
			
			driver = new ChromeDriver();
			driver.get("https://opensource-demo.orangehrmlive.com/");
			
			driver.manage().window().maximize();
			driver.manage().deleteAllCookies();
			driver.manage().timeouts().pageLoadTimeout(10, TimeUnit.SECONDS);	
		}
		
	  @Test(groups= {"Smoke"})
	  public void signIntest() 
	  {
		  driver.findElement(By.xpath("//input[@id='txtUsername']")).sendKeys("Admin");
		  driver.findElement(By.xpath("//input[@id='txtPassword']")).sendKeys("admin123");
		  driver.findElement(By.xpath("//input[@id='btnLogin']")).click();
		  System.out.println(driver.getTitle());
		  
	  }
	  
	  @AfterMethod
		 public void tearDown()
		 {
		    driver.close();
	  }
}

Testng xml as below

<?xml version = "1.0" encoding = "UTF-8"?>
<!DOCTYPE suite SYSTEM "http://testng.org/testng-1.0.dtd" >
<suite name = "Sample test Suite">
   <test name = "Sample test">   
   <groups>
     <run>
       <include name = "Smoke" />
     </run>
   </groups>
      <classes>
         <class name = "com.qa.tc.GroupTest" />
      </classes>
   </test>
</suite>

[krmahadevan]

The second sample you shared doesn’t have anything that can trigger your NPE.

The original sample that you shared, triggers an NPE because of a problem in your code.

Your WebDriver instantiation is being done via the @BeforeMethod annotation. But you are choosing to run tests via groups called Smoke to which you haven’t added your @BeforeMethod method and you haven’t added the alwaysRun=true attribute also. So your @BeforeMethod is not getting executed.

To fix the problem, either add alwaysRun=true or add Smoke group to your @BeforeMethod

[GirishBaliga123]

Thanks @krmahadevan It worked when used alwaysRun=true attribute in @BeforeMethod annotation