适配模式

定义：可以将截然不同的函数接口封装成统一的API

实际应用举例：1.PHP的数据库有mysql,mysqli,pdo3种，可以用适配器模式统一成一致

2.cache适配器，将memcache,redis,file,apc等不同的缓存函数，统一成一致

以实际应用举例1作为示例

$db = new IMooc\Database\MySQL();//$db = new IMooc\Database\MySQLi();//$db = new IMooc\Database\PDO();$db->connect(‘127.0.0.1‘, ‘root‘, ‘root‘, ‘test‘);$db->query("show databases");$db->close();

<?phpnamespace IMooc;

interface IDatabase{    function connect($host, $user, $passwd, $dbname);    function query($sql);    function close();}

<?phpnamespace IMooc\Database;

use IMooc\IDatabase;

class MySQL implements IDatabase{    protected $conn;    function connect($host, $user, $passwd, $dbname)    {        $conn = mysql_connect($host, $user, $passwd);        mysql_select_db($dbname, $conn);        $this->conn = $conn;    }

function query($sql)    {        $res = mysql_query($sql, $this->conn);        return $res;    }

function close()    {        mysql_close($this->conn);    }}

<?phpnamespace IMooc\Database;

use IMooc\IDatabase;

class MySQLi implements IDatabase{    protected $conn;

function connect($host, $user, $passwd, $dbname)    {        $conn = mysqli_connect($host,$user,$passwd,$dbname);        $this->conn = $conn;    }

function query($sql)    {        return mysqli_query($this->conn, $sql);    }

function close()    {        mysqli_close($this->conn);    }}

<?phpnamespace IMooc\Database;

use IMooc\IDatabase;

class PDO implements IDatabase{    protected $conn;    function connect($host, $user, $passwd, $dbname)    {        $conn = new \PDO("mysql:host=$host;dbname=$dbname", $user, $passwd);        $this->conn = $conn;    }

function query($sql)    {        return $this->conn->query($sql);    }

function close()    {        unset($this->conn);    }}

来自为知笔记(Wiz)