Java デザイン パターン ファクトリ メソッド パターンが明らかに

// 抽象工厂接口
interface ShapeFactory {
    Shape createShape(ShapeType type);
}

// 具体工厂类
class CircleFactory implements ShapeFactory {
    @Override
    public Shape createShape(ShapeType type) {
        return new Circle();
    }
}

// 具体工厂类
class SquareFactory implements ShapeFactory {
    @Override
    public Shape createShape(ShapeType type) {
        return new Square();
    }
}

// 产品类
class Shape {
    private String type;
    public Shape(String type) {
        this.type = type;
    }
    public String getType() {
        return type;
    }
}

// 圆形产品类
class Circle extends Shape {
    public Circle() {
        super("Circle");
    }
}

// 正方形产品类
class Square extends Shape {
    public Square() {
        super("Square");
    }
}

// 客户端代码
public class Main {
    public static void main(String[] args) {
        ShapeFactory circleFactory = new CircleFactory();
        Shape circle = circleFactory.createShape(ShapeType.CIRCLE);
        System.out.println(circle.getType()); // 输出: Circle

        ShapeFactory squareFactory = new SquareFactory();
        Shape square = squareFactory.createShape(ShapeType.SQUARE);
        System.out.println(square.getType()); // 输出: Square
    }
}