PHP面向?qū)ο笪宕笤瓌t之單一職責(zé)原則(SRP)詳解

interface Db_Adpater
{
  /**
   * 數(shù)據(jù)庫連接
   * @param $config 數(shù)據(jù)庫配置
   * @return mixed resource
   */
  public function connect($config);
  /**
   * 執(zhí)行數(shù)據(jù)庫查詢
   * @param $query 數(shù)據(jù)庫查詢的SQL字符串
   * @param $handle 連接對象
   * @return mixed
   */
  public function query($query,$handle);
}

class Db_Adapter_Mysql implements Db_Adpater
{
  private $_dbLink;  //數(shù)據(jù)庫連接字符串標(biāo)識
  /**
   * 數(shù)據(jù)庫連接函數(shù)
   * @param $config 數(shù)據(jù)庫配置
   * @return resource
   * @throws Db_Exception
   */
  public function connect($config)
  {
    if($this->_dbLink = @mysql_connect($config->host . (empty($config->port) ? '' : ':' . $config->prot) ,$config->user, $config->password, true))
    {
      if(@mysql_select_db($config->database, $this->_dbLink))
      {
        if($config->charset)
        {
          mysql_query("SET NAME '{$config->charset}'", $this->_dbLink);
        }
        return $this->_dbLink;
      }
    }
    throw new Db_Exception(@mysql_error($this->_dbLink));
  }
  /**
   * 執(zhí)行數(shù)據(jù)庫查詢
   * @param $query 數(shù)據(jù)庫查詢SQL字符串
   * @param $handle 連接對象
   * @return resource
   */
  public function query($query,$handle)
  {
    if($resource = @mysql_query($query,$handle))
      return $resource;
  }
}

class Db_Adapter_sqlite implements Db_Adpater
{
  private $_dbLink;  //數(shù)據(jù)庫連接字符串標(biāo)識
  public function connect($config)
  {
    if($this->_dbLink = sqlite_open($config->file, 0666, $error))
    {
      return $this->_dbLink;
    }
    throw new Db_Exception($error);
  }
  public function query($query, $handle)
  {
    if($resource = @sqlite_query($query,$handle))
    {
      return $resource;
    }
  }
}

class sqlFactory
{
  public static function factory($type)
  {
    if(include_once 'Drivers/' . $type . '.php')
    {
      $classname = 'Db_Adapter_'.$type;
      return new $classname;
    }
    else
      throw new Exception('Driver not found');
  }
}

$db = sqlFactory::factory('MySQL');
$db = sqlFactory::factory('SQLite');

/**
 * 廚師類，命令接受者與執(zhí)行者
 * Class cook
 */
class cook
{
  public function meal()
  {
    echo '番茄炒雞蛋',PHP_EOL;
  }
  public function drink()
  {
    echo '紫菜蛋花湯',PHP_EOL;
  }
  public function ok()
  {
    echo '完畢',PHP_EOL;
  }
}
//然后是命令接口
interface Command
{
  public function execute();
}

class MealCommand implements Command
{
  private $cook;
  //綁定命令接受者
  public function __construct(cook $cook)
  {
    $this->cook = $cook;
  }
  public function execute()
  {
    $this->cook->meal();//把消息傳給廚師，讓廚師做飯，下同
  }
}
class DrinkCommand implements Command
{
  private $cook;
  //綁定命令接受者
  public function __construct(cook $cook)
  {
    $this->cook = $cook;
  }
  public function execute()
  {
    $this->cook->drink();
  }
}

class cookControl
{
  private $mealcommand;
  private $drinkcommand;
  //將命令發(fā)送者綁定以命令接收器上面來
  public function addCommand(Command $mealcommand, Command $drinkcommand)
  {
    $this->mealcommand = $mealcommand;
    $this->drinkcommand = $drinkcommand;
  }
  public function callmeal()
  {
    $this->mealcommand->execute();
  }
  public function calldrink()
  {
    $this->drinkcommand->execute();
  }
}

$control = new cookControl;
$cook = new cook;
$mealcommand = new MealCommand($cook);
$drinkcommand = new DrinkCommand($cook);
$control->addCommand($mealcommand,$drinkcommand);
$control->callmeal();
$control->calldrink();