Selenium Grid Implementaiton with exisiting framework produce an Null pointer exception

Question

We have implemented the Selenium Grid (Distributed Test) Concept with our existing framework, while implemented its produce an Null Pointer Exception as of now i have an single package, with three class file (Baseclass, Loginclass, testcase)

Baseclass - getting my desired driver and navigate to application

class Baseclass {
    public WebDriver myDriver;
    public static String baseUrl;

    // Explicit Constructors
    public Baseclass() {
        baseUrl = "https://example.com/";
    }
    public void Navigate(String url) {
        String navigateToThisUrl = baseUrl + url;       
        myDriver.navigate().to(navigateToThisUrl);
    }
    public void GetDriver() throws MalformedURLException {
        threadDriver = new ThreadLocal<RemoteWebDriver>();
        DesiredCapabilities desiredCapabilities = new DesiredCapabilities();
        FirefoxProfile fp = new FirefoxProfile();
        desiredCapabilities.setCapability(FirefoxDriver.PROFILE, fp);
        desiredCapabilities.setBrowserName(DesiredCapabilities.firefox()
                .getBrowserName());
        myDriver = new RemoteWebDriver(new URL(
                "http://localhost:5555/wd/hub"), desiredCapabilities);
    }
    }

and in Loginclass navigate to the location (either QA or UAT etc.,)

public class Loginclass extends Baseclass {

    public Loginclass navigateToLogin() {
        Navigate("qa");
        return new Loginclass();
    }
    }

Testcase we have an test case and executed the same

public class TestcaseSearch extends Loginclass {
    @BeforeTest
    public final void Startup() throws MalformedURLException {
        Baseclass baseClass = new Baseclass();
        baseClass.GetDriver;        
        }       
    @Test
    public void fieldsSearch(String username, String password)
            throws Exception {      
        Loginclass loginClass = new Loginclass();
        navigateToLogin();
        }
        }

While Execute the above its produce an Null Pointer Exception

Baseclass: idsDriver.navigate().to(navigateToThisUrl);

Loginclass :Navigate("qa");

Let me know how can i rectify this

Exception output

java.lang.NullPointerException
    at com.Baseclass.Navigate(Baseclass.java:11)
    at com.Loginclass.Navigate(Loginclass.java:1)
    at com.TestcaseSearch.Navigate(TestcaseSearch.java:1)
    at com.Loginclass.navigateToLogin(Loginclass.java:4)
    at com.TestcaseSearch.fieldsSearch(TestcaseSearch.java:11)

Can you show where the NPE occurs, and include a full stack trace? — Andy Turner, Sep 29 '15 at 12:35
Don't set static fields in constructors: you are resetting `baseUrl` every time you create an instance. — Andy Turner, Sep 29 '15 at 12:37
Why are you creating a `new Baseclass` inside `TestcaseSearch`, a subclass of `Baseclass`? — Andy Turner, Sep 29 '15 at 12:40
@Andy stack trace java.lang.NullPointerException at com.Baseclass.Navigate(Baseclass.java:11) at com.Loginclass.Navigate(Loginclass.java:1) at com.TestcaseSearch.Navigate(TestcaseSearch.java:1) at com.Loginclass.navigateToLogin(Loginclass.java:4) at com.TestcaseSearch.FieldsSearch(TestcaseSearch.java:11) — Prabu, Sep 29 '15 at 12:42
please put that in your question, where you can format it legibly. — Andy Turner, Sep 29 '15 at 12:42
possible duplicate of [What is a Null Pointer Exception, and how do I fix it?](http://stackoverflow.com/questions/218384/what-is-a-null-pointer-exception-and-how-do-i-fix-it) — Andy Turner, Sep 29 '15 at 12:43

score 1 · Accepted Answer · answered Sep 29 '15 at 12:45

Your myDriver instance is null because you create a new instance of Baseclass in Startup(), which sets myDriver on itself rather than the actual test class instance.

Similarly, you don't need to create a new Loginclass in fieldsSearch, because TestcaseSearch is a subclass of Loginclass:

public class TestcaseSearch extends Loginclass {
    @BeforeTest
    public final void Startup() throws MalformedURLException {
        GetDriver();        
    }       

    @Test
    public void fieldsSearch(String username, String password)
            throws Exception {      
        navigateToLogin();
    }
}

Selenium Grid Implementaiton with exisiting framework produce an Null pointer exception

1 Answers1