PHP 의 Token 응용

gen_token();
 * 2.    Action    Token，             ，      ：
 * 		$isValid = Utils_Token::getInstance()->validate($token_value);
 * 3.            URL ：
 * 		Utils_Token::getInstance()->validate($token_value,'http://xx.xxx.com')
 * 
 * @package Utils
 * @author    
 * @version 1.0
 * @example
 * 		$token_value = Utils_Token::getInstance()->gen_token(); //  Token
 *		echo 'TOKEN_VALUE:'.$token_value.'
';				//  Token
 *		$checkValue = Utils_Token::getInstance()->validate($token_value);//    
 *		echo $checkValue;//    ：1-   0-  
 * 
 */
class Utils_Token {
	const TOKEN_NAME = 'TOKEN'; //    
	private static $instance; //    
	private function __construct() { //     
	}
	/**
	 *        
	 *
	 * @access public
	 * @return Token Utils_Token   
	 */
	public static function getInstance() {
		if (! isset ( $_SESSION ))
			session_start ();
		if (! isset ( self::$instance ))
			return new Utils_Token ();
		else
			return self::$instance;
	}
	
	/**
	 *     ,            
	 *
	 * @access public
	 * @return string    
	 */
	public function gen_token() {
		$hash = md5 ( uniqid ( rand () . 'WXT', true ) );
		$n = rand ( 0, 24 );
		$token = substr ( $hash, $n, 8 );
		$this->_tokenValue = $token;
		$this->destroy_token ();
		$_SESSION [self::TOKEN_NAME] = $this->_tokenValue;
		return $token;
	}
	
	/**
	 *     
	 *
	 * @access private
	 * @return void
	 */
	private function destroy_token() {
		if ($_SESSION [self::TOKEN_NAME])
			unset ( $_SESSION [self::TOKEN_NAME] );
	}
	
	/**
	 *         
	 *
	 * @access public
	 * @param string $token
	 *        	   
	 * @param string $url
	 *        	      URL
	 * @return boolean 1-     0-    
     *
	 */
	public function validate($token, $url = '') {
		if ($token == $_SESSION [self::TOKEN_NAME]) {
			$this->destroy_token ();
			return 1;
		} elseif ($url) {
			$this->destroy_token ();
			Header ( "Location: $url" );
		} else {
			$this->destroy_token ();
			return 0;
		}
	}
}
/*
$token_value = Utils_Token::getInstance()->gen_token(); //  Token
echo 'TOKEN_VALUE:'.$token_value.'
';				//  Token
$checkValue = Utils_Token::getInstance()->validate($token_value);//    
echo $checkValue;//    ：1-   0-  
*/