php简单的会话类代码

<?php 
class session 
{ 
static $sessionObject; 
/* $_SESSION['user'] == 0 , don't work . 
* == 1 , he is really user . 
*/ 
private function __construct() 
{ 
if(! ( isset($_SESSION['user']) && $_SESSION['user']==0 )) 
session_set_cookie_params(3600); session_start(); //Initialize14 }15 private function __clone() 
{ 
} 
public static function getObject() 
{ 
if(! self::$sessionObject instanceof self) 
$sessionObject = new session() ; 
return $sessionObject; 
} 
public function set_false() 
{ 
$_SESSION['user'] = 0 ; // for PHP>=5 
} 
public function set_true() 
{ 
if( isset($_SESSION['user']) ) 
$_SESSION['user'] = 1 ; 
else 
$this->error(); 
} 
public function get_status() 
{ 
return $_SESSION['user']; 
} 
public function end_session() 
{ 
session_destroy(); 
} 
public function error() 
{ 
} 
} 
?>

大概用法
example :
log in page : $session = session::getObject();
$session->set_ture(); // if $row['password'] ==
next page :

$session = session::getObject(); 
if($session->get_status()) 
// .... the user is really 
else 
// ....

log out : $session = session::getObject();
$session->end_session();
由get_status()返回当前用户是否有效登录