PHP中如何实现工厂模式？

<?php

// 抽象产品类
abstract class Product {
    abstract public function getName();
}

// 具体产品类：书籍
class Book extends Product {
    private $name;

    public function __construct($name) {
        $this->name = $name;
    }

    public function getName() {
        return $this->name;
    }
}

// 具体产品类：电子产品
class Electronics extends Product {
    private $name;

    public function __construct($name) {
        $this->name = $name;
    }

    public function getName() {
        return $this->name;
    }
}

// 具体产品类：服装
class Clothing extends Product {
    private $name;

    public function __construct($name) {
        $this->name = $name;
    }

    public function getName() {
        return $this->name;
    }
}

// 工厂类
class ProductFactory {
    public static function createProduct($type, $name) {
        switch ($type) {
            case 'book':
                return new Book($name);
            case 'electronics':
                return new Electronics($name);
            case 'clothing':
                return new Clothing($name);
            default:
                throw new InvalidArgumentException("Invalid product type");
        }
    }
}

// 使用工厂模式创建产品
$book = ProductFactory::createProduct('book', 'The Great Gatsby');
$electronics = ProductFactory::createProduct('electronics', 'iPhone');
$clothing = ProductFactory::createProduct('clothing', 'T-Shirt');

echo $book->getName() . "\n"; // 输出: The Great Gatsby
echo $electronics->getName() . "\n"; // 输出: iPhone
echo $clothing->getName() . "\n"; // 输出: T-Shirt