Run selenium tests across multiple browsers in parallel

package mypckg;

import java.util.concurrent.TimeUnit;

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.openqa.selenium.ie.InternetExplorerDriver;
import org.testng.annotations.*;

public class BaseTest {

    public WebDriver driver; //declared outside, so each  method in class can access
    
    @Parameters("browser") //parameter is a tag with attribute name = "browser" in testng.xml 
    @BeforeTest  //BeforeTest will execute before every Test(method) executes              
    public void setup(String browser) throws Exception {

        if(browser.equalsIgnoreCase("firefox"))
            {
            System.setProperty("webdriver.gecko.driver", "./geckodriver");
            driver = new FirefoxDriver();}
        else if(browser.equalsIgnoreCase("safari"))
            { 
            //File file = new file("./IEDriverServer.exe");
            //System.setProperty("webdriver.ie.driver", file.getAbsolutePath());
            driver = new SafariDriver();}
        else if(browser.equalsIgnoreCase("chrome"))
            {
            System.setProperty("webdriver.chrome.driver","./chromedriver");
            driver=new ChromeDriver();}
        else
            throw new Exception("browser name is not valid!");
    }
}

package mypckg;

import java.util.concurrent.TimeUnit;

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.openqa.selenium.ie.InternetExplorerDriver;
import org.testng.annotations.*;
import mypckg.BaseTest;

public class SampleTest extends BaseTest{
    
    @Test
    public void Login()
    {
        driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);
        driver.get("https://www.saucedemo.com/");
        
        WebElement uname = driver.findElement(By.id("user-name"));
        uname.sendKeys("standard_user");
        WebElement password = driver.findElement(By.id("password"));
        password.sendKeys("secret_sauce");
        driver.findElement(By.id("login-button")).click();
        
        String url = driver.getCurrentUrl();
        if (url.contains("inventory"))
        {
            System.out.println("test case: PASS");
        }        
    }
}

<?xml version="1.0" encoding="UTF-8"?> 
<!DOCTYPE suite SYSTEM "http://testng.org/testng-1.0.dtd"> 

<suite name="TestSuite" thread-count="2" parallel="tests" > 

<test name="ChromeTest">     
    <parameter name="browser" value="chrome" />     
    <classes>         
       <class name="mypckg.SampleTest"/>     
    </classes> 
</test> 

<test name="FirefoxTest">     
    <parameter name="browser" value="firefox" />    
    <classes>         
        <class name="mypckg.SampleTest"/>     
    </classes> 
</test> 

<test name="IETest">    
    <parameter name="browser" value="safari" />     
    <classes>        
        <class name="mypckg.SampleTest"/>  
    </classes> 
</test> 
</suite>