抽象工厂

在本例中，按钮和复选框将被作为产品。它们有两个变体：macOS 版和 Windows 版。

抽象工厂定义了用于创建按钮和复选框的接口。而两个具体工厂都会返回同一变体的两个产品。

客户端代码使用抽象接口与工厂和产品进行交互。同样的代码能与依赖于不同工厂对象类型的多种产品变体进行交互。

buttons: 第一个产品层次结构

buttons/Button.java

package refactoring_guru.abstract_factory.example.buttons;
 
/**
 * Abstract Factory assumes that you have several families of products,
 * structured into separate class hierarchies (Button/Checkbox). All products of
 * the same family have the common interface.
 *
 * This is the common interface for buttons family.
 */
public interface Button {
    void paint();
}

				

					
				
				

					
				
				

					
				
				

					
				
			

buttons/MacOSButton.java

package refactoring_guru.abstract_factory.example.buttons;
 
/**
 * All products families have the same varieties (MacOS/Windows).
 *
 * This is a MacOS variant of a button.
 */
public class MacOSButton implements Button {
 
    @Override
    public void paint() {
        System.out.println("You have created MacOSButton.");
    }
}

				

					
				
				

					
				
				

					
				
				

					
				
			

buttons/WindowsButton.java

package refactoring_guru.abstract_factory.example.buttons;
 
/**
 * All products families have the same varieties (MacOS/Windows).
 *
 * This is another variant of a button.
 */
public class WindowsButton implements Button {
 
    @Override
    public void paint() {
        System.out.println("You have created WindowsButton.");
    }
}

				

					
				
				

					
				
				

					
				
				

					
				
			

checkboxes: 第二个产品层次结构

checkboxes/Checkbox.java

package refactoring_guru.abstract_factory.example.checkboxes;
 
/**
 * Checkboxes is the second product family. It has the same variants as buttons.
 */
public interface Checkbox {
    void paint();
}

				

					
				
				

					
				
				

					
				
				

					
				
			

checkboxes/MacOSCheckbox.java

package refactoring_guru.abstract_factory.example.checkboxes;
 
/**
 * All products families have the same varieties (MacOS/Windows).
 *
 * This is a variant of a checkbox.
 */
public class MacOSCheckbox implements Checkbox {
 
    @Override
    public void paint() {
        System.out.println("You have created MacOSCheckbox.");
    }
}

				

					
				
				

					
				
				

					
				
				

					
				
			

checkboxes/WindowsCheckbox.java

package refactoring_guru.abstract_factory.example.checkboxes;
 
/**
 * All products families have the same varieties (MacOS/Windows).
 *
 * This is another variant of a checkbox.
 */
public class WindowsCheckbox implements Checkbox {
 
    @Override
    public void paint() {
        System.out.println("You have created WindowsCheckbox.");
    }
}

				

					
				
				

					
				
				

					
				
				

					
				
			

factories

factories/GUIFactory.java: 抽象工厂

package refactoring_guru.abstract_factory.example.factories;
 
import refactoring_guru.abstract_factory.example.buttons.Button;
import refactoring_guru.abstract_factory.example.checkboxes.Checkbox;
 
/**
 * Abstract factory knows about all (abstract) product types.
 */
public interface GUIFactory {
    Button createButton();
    Checkbox createCheckbox();
}

				

					
				
				

					
				
				

					
				
				

					
				
			

factories/MacOSFactory.java: 具体工厂（ mac­OS）

package refactoring_guru.abstract_factory.example.factories;
 
import refactoring_guru.abstract_factory.example.buttons.Button;
import refactoring_guru.abstract_factory.example.buttons.MacOSButton;
import refactoring_guru.abstract_factory.example.checkboxes.Checkbox;
import refactoring_guru.abstract_factory.example.checkboxes.MacOSCheckbox;
 
/**
 * Each concrete factory extends basic factory and responsible for creating
 * products of a single variety.
 */
public class MacOSFactory implements GUIFactory {
 
    @Override
    public Button createButton() {
        return new MacOSButton();
    }
 
    @Override
    public Checkbox createCheckbox() {
        return new MacOSCheckbox();
    }
}

				

					
				
				

					
				
				

					
				
				

					
				
			

factories/WindowsFactory.java: 具体工厂（Windows）

package refactoring_guru.abstract_factory.example.factories;
 
import refactoring_guru.abstract_factory.example.buttons.Button;
import refactoring_guru.abstract_factory.example.buttons.WindowsButton;
import refactoring_guru.abstract_factory.example.checkboxes.Checkbox;
import refactoring_guru.abstract_factory.example.checkboxes.WindowsCheckbox;
 
/**
 * Each concrete factory extends basic factory and responsible for creating
 * products of a single variety.
 */
public class WindowsFactory implements GUIFactory {
 
    @Override
    public Button createButton() {
        return new WindowsButton();
    }
 
    @Override
    public Checkbox createCheckbox() {
        return new WindowsCheckbox();
    }
}

				

					
				
				

					
				
				

					
				
				

					
				
			

app

app/Application.java: 客户端代码

package refactoring_guru.abstract_factory.example.app;
 
import refactoring_guru.abstract_factory.example.buttons.Button;
import refactoring_guru.abstract_factory.example.checkboxes.Checkbox;
import refactoring_guru.abstract_factory.example.factories.GUIFactory;
 
/**
 * Factory users don't care which concrete factory they use since they work with
 * factories and products through abstract interfaces.
 */
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: 程序配置

package refactoring_guru.abstract_factory.example;
 
import refactoring_guru.abstract_factory.example.app.Application;
import refactoring_guru.abstract_factory.example.factories.GUIFactory;
import refactoring_guru.abstract_factory.example.factories.MacOSFactory;
import refactoring_guru.abstract_factory.example.factories.WindowsFactory;
 
/**
 * Demo class. Everything comes together here.
 */
public class Demo {
 
    /**
     * Application picks the factory type and creates it in run time (usually at
     * initialization stage), depending on the configuration or environment
     * variables.
     */
    private static Application configureApplication() {
        Application app;
        GUIFactory factory;
        String osName = System.getProperty("os.name").toLowerCase();
        if (osName.contains("mac")) {
            factory = new MacOSFactory();
        } else {
            factory = new WindowsFactory();
        }
        app = new Application(factory);
        return app;
    }
 
    public static void main(String[] args) {
        Application app = configureApplication();
        app.paint();
    }
}

				

					
				
				

					
				
				

					
				
				

					
				
			

OutputDemo.txt: 执行结果

You create WindowsButton.
You created WindowsCheckbox.