In Java is it possible to merge two classes so that methods from both classes can be called from one?

Question

This maybe be an impossible task for Java, but I wondering if any of the pro's have a solution. [It's been years since I used Java, well College really]

I'm building a framework for QA. Please ask any questions or raise any flags if something doesn't make sense.

Using Selenium Webdriver, we have a driver class.

public class Driver {

private final String browser;
private final WebDriver driver;

public Driver(String browser) {
    driver = new RemoteWebDriver(new URL(Environment_address));
}

I mention this class first because it needs to be used by test classes running each test case, and libraries with additional methods. (Helper methods)

Such as

class UserPageUtils{
    private final Webdriver driver;

    public UserPageUtils(driver){
        this.driver = driver;
    }

    public void makeUsersLifeMiserable(){...}
}

and

class ActionPageUtils{
    private final Webdriver driver;

    public ActionPageUtils(driver){
        this.driver = driver
    }

    public void doSomethingCoolWithAction(){...}
}

With these examples, is there a way to merge to classes into a single class or variable? A design pattern I'm not thinking of. I have the following, how can I arrange the classes to do so that following is possible, or in similar effect.

public TestSuite extends AverageEverydayTestSuiteLikeTestNG{

@BeforeMethod
public void setUp(Object[] objects) {
    HelperUtils utils = merge('ActionPageUtils','UserPageUtils', driver);
    // Similarly in psuedo
    // HelperUtils utils = merge(new ActionPageUtils(driver), new UserPageUtils(driver));
}

@Test
public void testUserAction(HelperUtil utils){
    utils.makeUsersLifeMiserable();  //util has methods from both classes!!
    utils.doSomethingCoolWithAction();

    assert something is still passing.   
}

Is it possible to do such a thing in java? Create two wrappers in a single class. I can't wrap my head around the structuring. I feel like this is more possible in bash or something, but not sure if Java could do such a thing.

How would or could this be implemented?

Using [Java, Selenium, Groovy]

Answer 1

Java doesn't have multiple inheritance. You can though accomplish what you want in several ways:

Pure Interfaces:

interface UserPageUtils{
    public void makeUsersLifeMiserable();
}

interface ActionPageUtils{
    public void doSomethingCoolWithAction();
}

class PageUtils implements UserPageUtils, ActionPageUtils {
   //concrete implementations
}

Facade pattern:

class UserPageUtils{
    private final Webdriver driver;

    public UserPageUtils(driver){
        this.driver = driver;
    }

    public void makeUsersLifeMiserable(){...}
}

class ActionPageUtils{
    private final Webdriver driver;

    public ActionPageUtils(driver){
        this.driver = driver
    }

    public void doSomethingCoolWithAction(){...}
}

class PageUtils{
    private final Webdriver driver;
    private final ActionPageUtils action;
    private final UserPageUtils user;

    public void doSomethingCoolWithAction(){action.doSomethingCoolWithAction();}
    public void makeUsersLifeMiserable(){user.makeUsersLifeMiserable();}
}

Or if you're using java 8, you can have default methods in your interfaces:

    interface UserPageUtils{
       public Webdriver getDriver();
       default void makeUsersLifeMiserable(){
            //somewhere here you use getDriver();
       }
    }

    interface ActionPageUtils{
       public Webdriver getDriver();
       default void doSomethingCoolWithAction() {
           //somewhere here you use getDriver();
       }
    }

    class PageUtils implements UserPageUtils, ActionPageUtils {
        private final Webdriver driver;

        @Override
        public Webdriver getDriver() {
            return driver;
        }
    }

Answer 2

Use Facade Pattern like below, Instead of merge you can call constructor an HelperUtils class would be like this.

public class HelperUtils {

    ActionPageUtils actionPageUtils;
    UserPageUtils userPageUtils;
    public HelperUtils(ActionPageUtils actionPageUtils, UserPageUtils userPageUtils, Webdriver  driver) {
        this.actionPageUtils = actionPageUtils;
        this.userPageUtils = userPageUtils;
    }

    public void doSomethingCoolWithAction(){actionPageUtils.doSomethingCoolWithAction();}
    public void makeUsersLifeMiserable(){userPageUtils.makeUsersLifeMiserable();}

    public static void main(String[] args) {
        HelperUtils utils = new HelperUtils(new ActionPageUtils("Chrome"), new UserPageUtils("firefox"), driver);
        utils.makeUsersLifeMiserable();
        utils.doSomethingCoolWithAction();
    }

}

Disadvantage of this approach:

You have create new method always whenever you are updating the sub classes or merged classes.