在 pageObject 类中设置 WebDriver，然后在您的测试用例中调用它

Question

Can I write a method for WebDriver in a pageObject class, and then call the method in my testcase class?

public class setupMethods {

static WebDriver driver;

public static void setup(String browser) throws Exception{
    //Check if parameter passed from TestNG is 'firefox'
    if(browser.equalsIgnoreCase("firefox")){
    //create firefox instance
        System.setProperty("webdriver.gecko.driver", "U:\\path\\geckodriver.exe");
        WebDriver driver = new FirefoxDriver();
    }
    //Check if parameter passed as 'chrome'
    else if(browser.equalsIgnoreCase("chrome")){
        System.setProperty("webdriver.chrome.driver", "U:\\selenium\\chromedriver.exe");
        WebDriver driver = new ChromeDriver();
    }
    //Check if parameter passed as 'Edge'
            else if(browser.equalsIgnoreCase("IE")){
                System.setProperty("webdriver.ie.driver","U:\\path\\IEDriverServer.exe");
                InternetExplorerDriver driver;
                driver = new InternetExplorerDriver();
            }
    else{
        //If no browser passed throw exception
        throw new Exception("Browser is not correct");
    }
    driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);
}

}

This is a method that I would like to call in my test case class, but when I run the test it starts Chrome (or any other browser), but then returns java.lang.NullPointerException when it comes to the line of code where the driver needs to maximize the window driver.manage().window().maximize();

Answer 1

You're having local variable driver in your method, that's why you're getting this exception. Remove type declaration for driver in method body.

Answer 2

Here is the Answer to your Question:

Answering straight, Yes , you can write a method for WebDriver in a pageObject class, and then call the method in your testcase class

You need to consider certain changes in your code as follows:

1. As you need to call the method in my testcase you need to get back the WebDriver instance as a return. So change the method from public static void setup(String browser) to public static WebDriver setup(String browser)

2. As you have already declared the instance of the WebDriver as in static WebDriver driver; , so you no more need to mention the Class name WebDriver again while initializing the driver as in WebDriver driver = new FirefoxDriver();

Functionally, this is causing you NullPointerException in your code.

3. There is no best practice but I would prefer to check the passed parameter String browser in if loops only.

4. Once you have completed all the actions within this class, return the WebDriver instance.

5. Your own code with some simple tweaks will look like:

    public class setupMethods { static WebDriver driver; public static void setup(String browser) throws Exception { //Check if parameter passed from TestNG is 'firefox' if(browser.equalsIgnoreCase("firefox")) { //create firefox instance System.setProperty("webdriver.gecko.driver", "U:\\path\\geckodriver.exe"); driver = new FirefoxDriver(); } //Check if parameter passed as 'chrome' if(browser.equalsIgnoreCase("chrome")) { System.setProperty("webdriver.chrome.driver", "U:\\selenium\\chromedriver.exe"); driver = new ChromeDriver(); } //Check if parameter passed as 'Edge' if(browser.equalsIgnoreCase("IE")) { System.setProperty("webdriver.ie.driver","U:\\path\\IEDriverServer.exe"); InternetExplorerDriver driver; driver = new InternetExplorerDriver(); } else { //If no browser passed throw exception throw new Exception("Browser is not correct"); } driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS); return driver; } }

   Let me know if this Answers your Question.

Answer 3

I have resolved the issue that I had...after using code that @debanjanB suggested, and using constructor for a driver in page object classes by using

public name_of_pageobject_class(WebDriver driver){ 

    this.driver = setupMethods.driver; 

    }

and calling driver in test cases classes as:

WebDriver driver = setupMethods.setup("chrome");

Please correct me if anything might be wrong....but this now works.