抽象工厂模式结构

跨平台UI类示例

// Button.java
public interface Button {
    void paint();
}

// MacOSButton.java
public class MacOSButton implements Button {
    @Override
    public void paint() {
        System.out.println("You have created MacOSButton.");
    }
}

// WindowsButton.java
public class WindowsButton implements Button {
    @Override
    public void paint() {
        System.out.println("You have created WindowsButton.");
    }
}

// Checkbox.java
public interface Checkbox {
    void paint();
}

// MacOSCheckbox.java
public class MacOSCheckbox implements Checkbox {
    @Override
    public void paint() {
        System.out.println("You have created MacOSCheckbox.");
    }
}

// WindowsCheckbox.java
public class WindowsCheckbox implements Checkbox {
    @Override
    public void paint() {
        System.out.println("You have created WindowsCheckbox.");
    }
}

// GUIFactory.java
public interface GUIFactory {
    Button createButton();
    Checkbox createCheckbox();
}

// MacOSFactory.java
public class MacOSFactory implements GUIFactory {
    @Override
    public Button createButton() {
        return new MacOSButton();
    }

    @Override
    public Checkbox createCheckbox() {
        return new MacOSCheckbox();
    }
}

// WindowsFactory.java
public class WindowsFactory implements GUIFactory {
    @Override
    public Button createButton() {
        return new WindowsButton();
    }

    @Override
    public Checkbox createCheckbox() {
        return new WindowsCheckbox();
    }
}

// Application.java
public class Application {
    private Button button;
    private Checkbox checkbox;

    public Application(GUIFactory factory) {
        button = factory.createButton();
        checkbox = factory.createCheckbox();
    }

    public void paint() {
        button.paint();
        checkbox.paint();
    }
}

// Demo.java
import java.util.Locale;

public class Demo {
    private static Application configureApplication() {
        Application app;
        GUIFactory factory;
        String osName = System.getProperty("os.name").toLowerCase(Locale.ROOT);
        if (osName.contains("mac")) {
            factory = new MacOSFactory();
            app = new Application(factory);
        } else {
            factory = new WindowsFactory();
            app = new Application(factory);
        }
        return app;
    }

    public static void main(String[] args) {
        Application app = configureApplication();
        app.paint();
    }
}