1.8. 静态工厂¶
1.8.1. 目的¶
与 抽象工厂 类似,静态工厂模式用于创建一系列互相关联或依赖的对象。它与抽象工厂模式的区别在于,静态工厂模式仅使用 一个静态方法 来创建所有它可以创建的类型。通常,这个静态方法被命名为:factory
或 build
。
1.8.2. UML 图¶

1.8.3. 代码¶
你可以在 GitHub 上找到这些代码
StaticFactory.php
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 | <?php
declare(strict_types=1);
namespace DesignPatterns\Creational\StaticFactory;
use InvalidArgumentException;
/**
* Note1: Remember, static means global state which is evil because it can't be mocked for tests
* Note2: Cannot be subclassed or mock-upped or have multiple different instances.
*/
final class StaticFactory
{
public static function factory(string $type): Formatter
{
return match ($type) {
'number' => new FormatNumber(),
'string' => new FormatString(),
default => throw new InvalidArgumentException('Unknown format given'),
};
}
}
|
Formatter.php
1 2 3 4 5 6 7 8 9 10 | <?php
declare(strict_types=1);
namespace DesignPatterns\Creational\StaticFactory;
interface Formatter
{
public function format(string $input): string;
}
|
FormatString.php
1 2 3 4 5 6 7 8 9 10 11 12 13 | <?php
declare(strict_types=1);
namespace DesignPatterns\Creational\StaticFactory;
class FormatString implements Formatter
{
public function format(string $input): string
{
return $input;
}
}
|
FormatNumber.php
1 2 3 4 5 6 7 8 9 10 11 12 13 | <?php
declare(strict_types=1);
namespace DesignPatterns\Creational\StaticFactory;
class FormatNumber implements Formatter
{
public function format(string $input): string
{
return number_format((int) $input);
}
}
|
1.8.4. 测试¶
Tests/StaticFactoryTest.php
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 | <?php
declare(strict_types=1);
namespace DesignPatterns\Creational\StaticFactory\Tests;
use InvalidArgumentException;
use DesignPatterns\Creational\StaticFactory\FormatNumber;
use DesignPatterns\Creational\StaticFactory\FormatString;
use DesignPatterns\Creational\StaticFactory\StaticFactory;
use PHPUnit\Framework\TestCase;
class StaticFactoryTest extends TestCase
{
public function testCanCreateNumberFormatter()
{
$this->assertInstanceOf(FormatNumber::class, StaticFactory::factory('number'));
}
public function testCanCreateStringFormatter()
{
$this->assertInstanceOf(FormatString::class, StaticFactory::factory('string'));
}
public function testException()
{
$this->expectException(InvalidArgumentException::class);
StaticFactory::factory('object');
}
}
|