抽象工廠，提供一個工廠接口，用於創建依賴對象的家族，不需要明確指定具體類。可以理解是多個工廠方法的組合。

例如一個款手機是有電池、相機、處理器、屏幕組成的，它其中包含了不同的對象，我們創建時需要創建多個不同類型的對象，而工廠方法只能創建一種類型的對象，滿足不了這種需求。那我們可以把多個工廠方法組合到一起，用來創建多個產品。

首先我們先定義抽象工廠，他可以生產電池、相機、處理器、屏幕

public interface BasePhoneFactory {

    public BaseCamara createCamara();

    public BaseBattery createBattery();

    
 
public BaseScreen createScreen();

    public BaseCpu createCpu();

}

然後創建各個抽象的產品

public interface BaseBattery {

    public void name();

}

public interface BaseCamara {
    
    public void name();
    
}

public interface BaseCpu {
    
    public void
 
 name();
    
}

public interface BaseScreen {
    
    public void name();
    
}

然後各個產品的實現類

public class Battery_3000 implements BaseBattery {
    @Override
    public void name() {
        System.out.println("3000毫安鋰電池");
    }
}

public class Battery_3800 implements BaseBattery {
    @Override
    
 
public void name() {
        System.out.println("3800毫安鋰電池");
    }
}

public class Camara_1200 implements BaseCamara {
    @Override
    public void name() {
        System.out.println("1200W像素相機");
    }
}

public class Camara_1800 implements BaseCamara {
    @Override
    public void name() {
        System.out.println("1800W像素相機");
    }
}

public class Cpu_4_8 implements BaseCpu {
    @Override
    public void name() {
        System.out.println("4核8線程處理器");
    }
}

public class Cpu_6_12 implements BaseCpu {
    @Override
    public void name() {
        System.out.println("6核12線程處理器");
    }
}

public class Screen_1080 implements BaseScreen {
    @Override
    public void name() {
        System.out.println("1080P屏幕");
    }
}

public class Screen_1440 implements BaseScreen {
    @Override
    public void name() {
        System.out.println("1440P屏幕");
    }
}

現在就是我們工廠的創建了

public class PhoneFactory_2018 implements BasePhoneFactory {
    @Override
    public BaseCamara createCamara() {
        return new Camara_1200();
    }

    @Override
    public BaseBattery createBattery() {
        return new Battery_3000();
    }

    @Override
    public BaseScreen createScreen() {
        return new Screen_1080();
    }

    @Override
    public BaseCpu createCpu() {
        return new Cpu_4_8();
    }
}

public class PhoneFactory_2019 implements BasePhoneFactory {
    @Override
    public BaseCamara createCamara() {
        return new Camara_1800();
    }

    @Override
    public BaseBattery createBattery() {
        return new Battery_3800();
    }

    @Override
    public BaseScreen createScreen() {
        return new Screen_1440();
    }

    @Override
    public BaseCpu createCpu() {
        return new Cpu_6_12();
    }
}

下面是手機基類和它的實現類

public abstract class BasePhone {
    /**
     * 電池
     */
    protected BaseBattery battery;
    /**
     * 相機
     */
    protected BaseCamara camara;
    /**
     * 處理器
     */
    protected BaseCpu cpu;
    /**
     * 屏幕
     */
    protected BaseScreen screen;

    public void display() {
        battery.name();
        camara.name();
        cpu.name();
        screen.name();
    }

    public abstract void getPhone();
}

public class Phone_2018 extends BasePhone {

    BasePhoneFactory phoneFactory;

    public Phone_2018() {
        phoneFactory = new PhoneFactory_2018();
    }

    @Override
    public void getPhone() {
        this.camara = this.phoneFactory.createCamara();
        this.battery = this.phoneFactory.createBattery();
        this.cpu = this.phoneFactory.createCpu();
        this.screen = this.phoneFactory.createScreen();
    }

    @Override
    public void display() {
        System.out.println("2018年款手機");
        super.display();
    }
}

public class Phone_2019 extends BasePhone {

    BasePhoneFactory phoneFactory;

    public Phone_2019() {
        phoneFactory = new PhoneFactory_2019();
    }

    @Override
    public void getPhone() {
        this.camara = this.phoneFactory.createCamara();
        this.battery = this.phoneFactory.createBattery();
        this.cpu = this.phoneFactory.createCpu();
        this.screen = this.phoneFactory.createScreen();
    }

    @Override
    public void display() {
        System.out.println("2019年款手機");
        super.display();
    }
}

測試代碼

public class Main {

    public static void main(String[] args) {
        BasePhone phone1 = new Phone_2018();
        phone1.getPhone();
        phone1.display();

        System.out.println("-------------------");

        BasePhone phone2 = new Phone_2019();
        phone2.getPhone();
        phone2.display();
    }
}

輸出結果

抽象工廠一個具體的工廠就能創建出多個產品，和工廠方法相比，減少了具體工廠的數量。

但是，如果需要給抽象工廠中添加一個成員，就需要改動所有的工廠，擴展性就比較差了。

設計模式（5）抽象工廠模式