存在Shape，Color兩個(gè)工廠
這兩個(gè)工廠又繼承抽象類AbstractFactory。
自上而下

先創(chuàng)建頂層抽象工廠：AbstractFactory.java，有兩個(gè)抽象方法，傳一個(gè)String參數(shù)，返回Shap/Color對象

public abstract class AbstractFactory {
    abstract Shape getShape(String shape);
    abstract Color getColor(String color);

}

然后創(chuàng)建ShapeFactory.java和ColorFactory.java，繼承AbstractFactory.java。根據(jù)不同的傳參返回不同的Shape/Color。

public class ShapeFactory extends AbstractFactory {
    @Override
    Shape getShape(String shape) {
        switch (shape){
            case "Circle":{
                return new Circle();
            }
            case "Square":{
                return new Square();
            }

        }

        return null;
    }

    @Override
    Color getColor(String color) {
        return null;
    }
}



public class ColorFactoyr extends AbstractFactory {

    @Override
    Shape getShape(String shape) {
        return null;
    }

    @Override
    Color getColor(String color) {
        switch (color){
            case "Red":{
                return new Red();
            }

            case "Green":{
                return new Green();
            }
        }
        return null;
    }
}

創(chuàng)建兩個(gè)接口Shape.java和Color.java，給Shape接口一個(gè)draw()方法，給Color接口一個(gè)fill()方法

public interface Shape {
    void draw();
}

public interface Color {
    void fill();
}

創(chuàng)建Shape和Color的實(shí)現(xiàn)類

public class Square implements Shape {

    @Override
    public void draw() {
        System.out.println("drawing square...");
    }
}
public class Circle implements Shape {
    @Override
    public void draw() {
        System.out.println("drawing circle....");
    }
}

-------------------------------------------------------------------
public class Green implements Color{

    @Override
    public void fill() {
        System.out.println("filling green...");
    }
}

public class Red implements Color{

    @Override
    public void fill() {
        System.out.println("filling red...");
    }
}

這樣就完成了抽象工廠模式，就是有一個(gè)抽象類用來生成工廠類，最后寫一個(gè)測試方法驗(yàn)證下

public class AbstractFactoryTest {
    public static void main(String[] args) {

        AbstractFactory shapeFactory = new ShapeFactory();
        Shape shape = shapeFactory.getShape("Circle");
        shape.draw();

        AbstractFactory colorFactory = new ColorFactoyr();
        Color color = colorFactory.getColor("Red");
        color.fill();


        }
    }