结构型--适配器模式

设计模式

适配器模式是将类或者对象结合在一起形成复杂的、功能更为强大的结构
用适配器模式来包装其他一些不兼容的类或对象

应用场景

• 支付
• 数据库
• 复杂业务逻辑接口使用适配器接口对外提供数据

类适配器

接口:

<?php
/**
 * 接口
 *
 * @author    Luffy (lufei@swoole.com)
 * @date      2019/11/1
 * @copyright Swoole, Inc.
 * @package   sy-records/design-patterns
 */
namespace Luffy\DesignPatterns\Adapter\ClassAdapter;
interface DatabaseTarget
{
    public function set();
    public function get();
}

适配者类

<?php
/**
 * 适配者类
 *
 * @author    Luffy (lufei@swoole.com)
 * @date      2019/11/1
 * @copyright Swoole, Inc.
 * @package   sy-records/design-patterns
 */
namespace Luffy\DesignPatterns\Adapter\ClassAdapter;
class DatabaseAdaptee
{
    protected $driver = "mysql";
    public function set()
    {
        echo "use {$this->driver}.\n";
    }
}

适配器类 继承适配者类实现接口

<?php
/**
 * 适配器类
 *
 * @author    Luffy (lufei@swoole.com)
 * @date      2019/11/1
 * @copyright Swoole, Inc.
 * @package   sy-records/design-patterns
 */
namespace Luffy\DesignPatterns\Adapter\ClassAdapter;
class DatabaseAdapter extends DatabaseAdaptee implements DatabaseTarget
{
    public function __construct()
    {
        $this->driver = "pdo";
    }
    public function get()
    {
        echo "used {$this->driver}.\n";
    }
}

客户类

<?php
/**
 * 客户类
 *
 * @author    Luffy (lufei@swoole.com)
 * @date      2019/11/1
 * @copyright Swoole, Inc.
 * @package   sy-records/design-patterns
 */
namespace Luffy\DesignPatterns\Adapter\ClassAdapter;
require __DIR__ . '/../../vendor/autoload.php';
class Client
{
    public static function run()
    {
        // 适配者
        $adaptee = new DatabaseAdaptee();
        $adaptee->set();
        // 适配器
        $adapter = new DatabaseAdapter();
        $adapter->set();
        $adapter->get();
    }
}
Client::run();

对象适配器 (耦合度更低)

接口

<?php
/**
 * 接口
 *
 * @author    Luffy (lufei@swoole.com)
 * @date      2019/11/1
 * @copyright Swoole, Inc.
 * @package   sy-records/design-patterns
 */
namespace Luffy\DesignPatterns\Adapter\ObjectAdapter;
interface DatabaseTarget
{
    public function set();
    public function get();
}

适配者类

<?php
/**
 * 适配者类
 *
 * @author    Luffy (lufei@swoole.com)
 * @date      2019/11/1
 * @copyright Swoole, Inc.
 * @package   sy-records/design-patterns
 */
namespace Luffy\DesignPatterns\Adapter\ObjectAdapter;
class DatabaseAdaptee
{
    public $driver = "mysql";
    public function set()
    {
        echo "use {$this->driver}.\n";
    }
} 

适配器类 实现接口

<?php
/**
 * 适配器类
 *
 * @author    Luffy (lufei@swoole.com)
 * @date      2019/11/1
 * @copyright Swoole, Inc.
 * @package   sy-records/design-patterns
 */
namespace Luffy\DesignPatterns\Adapter\ObjectAdapter;
class DatabaseAdapter implements DatabaseTarget
{
    protected $adaptee;
    public function __construct(DatabaseAdaptee $adaptee)
    {
        $this->adaptee = $adaptee;
        $adaptee->driver = "mysqli";
    }
    public function set()
    {
        echo "use {$this->adaptee->driver}.\n";
    }
    public function get()
    {
        echo "used {$this->adaptee->driver}.\n";
    }
}

客户类 对象注入

<?php
/**
 * 客户类
 *
 * @author    Luffy (lufei@swoole.com)
 * @date      2019/11/1
 * @copyright Swoole, Inc.
 * @package   sy-records/design-patterns
 */
namespace Luffy\DesignPatterns\Adapter\ObjectAdapter;
require __DIR__ . '/../../vendor/autoload.php';
class Client
{
    public static function run()
    {
        $adaptee = new DatabaseAdaptee();
        $adaptee->set();
        // 适配器
        $adapter = new DatabaseAdapter($adaptee);
        $adapter->set();
        $adapter->get();
    }
}
Client::run();

参考资料:
swoole微课堂
示例代码