laravel 抽象工厂设计模式代码

Laravel 的抽象工厂设计模式代码看起来大致像这样：

<?php

namespace App\Factories;

use App\Contracts\Shape;

interface ShapeFactory
{
    public function makeCircle(): Shape;

    public function makeRectangle(): Shape;

    public function makeSquare(): Shape;
}

class CircleFactory implements ShapeFactory
{
    public function makeCircle(): Shape
    {
        return new Circle;
    }

    public function makeRectangle(): Shape
    {
        throw new \Exception('This factory can only make circles.');
    }

    public function makeSquare(): Shape
    {
        throw new \Exception('This factory can only make circles.');
    }
}

class RectangleFactory implements ShapeFactory
{
    public function makeCircle(): Shape
    {
        throw new \Exception('This factory can only make rectangles.');
    }

    public function makeRectangle(): Shape
    {
        return new Rectangle;
    }

    public function makeSquare(): Shape
    {
        throw new \Exception('This factory can only make rectangles.');
    }
}

class SquareFactory implements ShapeFactory
{
    public function makeCircle(): Shape
    {
        throw new \Exception('This factory can only make squares.');
    }

    public function makeRectangle(): Shape
    {
        throw new \Exception('This factory can only make squares.');
    }

    public function makeSquare(): Shape
    {
        return new Square;
    }
}

在这个例子中，我们定义了一个 `ShapeFactory` 接口和三个具体的工厂类，分别是 `CircleFactory`、`RectangleFactory` 和 `SquareFactory`。这三个工厂类都实现了 `ShapeFactory` 接口，并定义了如何创建圆形、矩形和正方形。

使用这些工厂类的方式如下：

$circleFactory = new CircleFactory;
$circle = $circleFactory->makeCircle();

$rectangleFactory = new RectangleFactory;
$rectangle = $rectangleFactory->makeRectangle();

$squareFactory = new SquareFactory;
$square = $squareFactory->makeSquare();

抽象工厂模式是一种创建型设计模式，它通过定义一个抽象工厂接口来创建一系列相关的产品，而不需要指定它