适配器模式

  1. 适配器模式将截然不同的函数接口封装成对立的api

  2. 理论利用：php数据操作有mysql、mysqli、pdo，能够适配器模式对立成统一的。相似还有cache适配器。将memecache、redis、file、apc等不同缓存，对立成统一

    // 应用数据库进行演示interface IDatabase { public function connect($host,$user,$passwd,$dbname);  public function query($sql);  public function close();}class mysql implements IDatabase { public function connect($host,$user,$pwd,$dbname){     mysql_connect();     mysql_select_db(); }   public function query ($sql) {     mysql_query($sql); }  public function close(){     mysql_close() }}class PDO implements IDatabase { private $pdo;  public function connect($host,$user,$pwd,$dbname){    $this->pdo = new \PDO('mysql:host=$host;dbname=$dbname',$user,$pwd); }   public function query ($sql) {    $this->pdo->query($sql) }  public function close(){     unset($this->pdo)   }}