CODEWITHSUNDEEP
javadesign-patterns
optional
optional

Reputation: 3350

AbstractFactory design pattern

I have created a following example . does this follows AbstractFactory design pattern ?

ButtonType.java

public enum ButtonType {
    WIN, LINUX, MAC
}

Button.java

public interface Button {
    ButtonType getButtonType();

    void actionListener();
}

LinuxButton.java

public class LinuxButton implements Button {

    @Override
    public ButtonType getButtonType() {
        return ButtonType.LINUX;
    }

    @Override
    public void actionListener() {
        System.out.println("Linux Button created");

    }

}

WinButton.java

public class WinButton implements Button {

    @Override
    public ButtonType getButtonType() {
        return ButtonType.WIN;
    }

    @Override
    public void actionListener() {
        System.out.println("Window Button Created");

    }

}

MacButton.java

public class MacButton implements Button {

    @Override
    public ButtonType getButtonType() {
        return ButtonType.MAC;
    }

    @Override
    public void actionListener() {
        System.out.println("Mac Button Created");

    }

}

ButtonFactory.java

public interface ButtonFactory {

    Button createButton();
}

LinuxButtonFactory.java

public class LinuxButtonFactory implements ButtonFactory {

    @Override
    public Button createButton() {
        System.out.println("creating Linux Button");
        return new LinuxButton();
    }

}

WinButtonFactory.java

public class WinButtonFactory implements ButtonFactory {

    @Override
    public Button createButton() {
        System.out.println("creating window Button");
        return new WinButton();
    }

}

MacButtonFactory.java

public class MacButtonFactory implements ButtonFactory {

    @Override
    public Button createButton() {
        System.out.println("Creating MAC Button");
        return new MacButton();
    }

}

AbstractButtonFactory.java

public abstract class AbstractButtonFactory {

    public static ButtonFactory getButtonFactory(ButtonType bt) {
        ButtonFactory btnFactory = null;
        switch (bt) {
        case WIN:
            btnFactory = new WinButtonFactory();
            break;
        case LINUX:
            btnFactory = new LinuxButtonFactory();
            break;
        default:
            btnFactory = new MacButtonFactory();
        }
        return btnFactory;
    }

}

and finally the main calss

public class AbstractFactoryObjectDemo {

    public static void main(String[] args) {

        ButtonFactory factory = AbstractButtonFactory.getButtonFactory(ButtonType.LINUX);
        Button linuxButton = factory.createButton();
        System.out.println(linuxButton.getButtonType().toString());
    }

}

I want to make sure is this pattern follow AbstractFactory Design Pattern ,if it doesn't what changes should be made?

Upvotes: 0

Views: 213

Answers (3)

dstar55
dstar55

Reputation: 954

Maybe you can consider combination between Bridge and Abstract Factory.

Imagine that you have a need to add new graphical item in addition to Button let say ComboBox, or that you have additional platform in addition to Win/Linux/Mac.
Then pure Abstract Factory will not be flexible, therefore Bridge pattern can be used in order to separate abstraction(Button, ComboBox, ...) and platform specific implementation(Win/Linux/Mac).

Upvotes: 0

Andreas Dolk
Andreas Dolk

Reputation: 114837

The implementation is ok. You have abstracted the button and the factory and that's the main goal for the pattern.

On an implementation side note: the getButtonFactory method on the factory is pretty useless, you can simply remove it an all the implementations from the real factories.

When a user calls the static method on the abstract factory, he already gets an instance of a factory and doesn't have to call a method on this factory which simply would return itself again. So drop this method :)

Upvotes: 1

StanislavL
StanislavL

Reputation: 57421

You should split the interface

public interface ButtonFactory {
    ButtonFactory getButtonFactory(ButtonType bt);
    Button createButton();
}

Into 2 different ones

public interface ButtonFactory {
    ButtonCreator getButtonFactory(ButtonType bt);
}

and 

public Button ButtonCreator {
    Button createButton();
}

First one creates ButtonCreator (depending on type) and ButtonCreator keeps the type inside and creates button of the type

:Updated

Upvotes: 1

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