dataProvider with #Before testng - selenium

Question

I am working with one TestNG script with SauceLab and Jenkins. I stuck with one problem. When I run my project from Jenkins I will select browsers from there, so I can use it with "dataProvider", but dataProvider is only working with #Test annotations, I want to use dataProvider with #before.
Steps:
#Before will initialize the driver (Webdriver) object.
#Test with execute first test case with driver object.
#Test (2nd) with execute second test case with same driver object.
public class test
{
Webdriver driver;
// Over here I want to use #Before
#Test(dataProvider = "dynamicParameters", priority = 0, alwaysRun = true)
public void init(String browser, String version, String os, Method method) throws Exception
{
System.out.println("Init Method");
String BASE_URL = System.getProperty("baseUrl");
PCRUtils pcrUtils = new PCRUtils();
driver = pcrUtils.createDriver(browser, version, os, method.getName());
driver.get(BASE_URL);
driver.manage().window().maximize();
Thread.sleep(50000);
}
#Test(priority = 1)
public void verifyTitle() throws InterruptedException
{
AccountPage accountPage = new AccountPage();
accountPage.verifyTitle(driver);
}
}

Answer 1

TestNG "#before" methods cannot be used directly with a #DataProvider.
A #BeforeMethod can access the list of parameters (TestNG - 5.18.1 - Native dependency injection):
Any #BeforeMethod can declare a parameter of type Object[]. This parameter will receive the list of parameters that are about to be fed to the upcoming test method, which could be either injected by TestNG, such as java.lang.reflect.Method or come from a #DataProvider
But a #BeforeMethod "will be run before each test method" and what you want is something more like #BeforeClass which "will be run before the first test method in the current class is invoked" (TestNG - 2 - Annotations). Unfortunately #BeforeClass cannot access the list of parameters via TestNG's native dependency injection like a #BeforeMethod can.
A #Factory however can be used to accomplish the initial, data-driven setup with a #DataProvider. e.g.:
public class test
{
WebDriver driver;
#Factory(dataProvider = "dynamicParameters")
public test(String browser, String version, String os, Method method) throws Exception
{
System.out.println("Init Method");
String BASE_URL = System.getProperty("baseUrl");
PCRUtils pcrUtils = new PCRUtils();
driver = pcrUtils.createDriver(browser, version, os, method.getName());
driver.get(BASE_URL);
driver.manage().window().maximize();
Thread.sleep(50000);
}
#Test(priority = 1)
public void verifyTitle() throws InterruptedException
{
AccountPage accountPage = new AccountPage();
accountPage.verifyTitle(driver);
}
#Test(priority = 2)
public void verifySomethingElse() throws InterruptedException
{
// execute second test case with same driver object.
}
}
See TestNG - 5.8 - Factories for more details.