Null pointer exception in TestNG - selenium

Question

My code is:
package ant;
import java.util.concurrent.TimeUnit;
import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.openqa.selenium.interactions.Actions;
import org.testng.annotations.Test;
import org.testng.annotations.BeforeMethod;
public class NewTestNG {
public WebDriver driver;
#BeforeMethod
public void LAunchbrowser() {
WebDriver driver = new FirefoxDriver();
driver.get("https://www.google.co.in/");
driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);
}
#Test
public void main() {
Actions action = new Actions(driver);
WebElement a= driver.findElement(By.xpath(".//*[#id='gs_htif0']"));
action.moveToElement(a).click().sendKeys("Shirt").build().perform();
driver.findElement(By.xpath("//div[#value='Search']")).click();
}
}
I'm getting NullPointerException:
FAILED: main
java.lang.NullPointerException
at org.openqa.selenium.interactions.Actions.<init>(Actions.java:44)
at ant.NewTestNG.main(NewTestNG.java:25)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:108)
at org.testng.internal.Invoker.invokeMethod(Invoker.java:661)
at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:869)
at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1193)
at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:126)
at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:109)
at org.testng.TestRunner.privateRun(TestRunner.java:744)
at org.testng.TestRunner.run(TestRunner.java:602)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:380)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:375)
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:340)
at org.testng.SuiteRunner.run(SuiteRunner.java:289)
at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
at org.testng.TestNG.runSuitesSequentially(TestNG.java:1301)
at org.testng.TestNG.runSuitesLocally(TestNG.java:1226)
at org.testng.TestNG.runSuites(TestNG.java:1144)
at org.testng.TestNG.run(TestNG.java:1115)
at org.testng.remote.AbstractRemoteTestNG.run(AbstractRemoteTestNG.java:132)
at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:230)
at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:76)
===============================================
Default test
Tests run: 1, Failures: 1, Skips: 0
===============================================
===============================================
Default suite
Total tests run: 1, Failures: 1, Skips: 0
===============================================
What's wrong with my code?

Answer 1

In LaunchBrowser() you declared driver again instead of using the class instance. Change it to
#BeforeMethod
public void LaunchBrowser() {
driver = new FirefoxDriver();
driver.get("https://www.google.co.in/");
driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);
}
and it should work. The problem is that when you declared driver in LaunchBrowser(), the scope of that variable is inside the method only so the class variable, driver doesn't get used. So when you are outside of the method and try to reference driver, it's null... thus the exception.
You really need to spend some time learning how to debug your own programs. If you put a break point at the start of the script and stepped through it, you should have been able to find this yourself.