[CakePHP]GET Shorten URL using BitlyAPI

BitlyAPI.php

<?php
// app/Lib/BitlyAPI.php
App::uses('HttpSocket', 'Network/Http');
class BitlyAPI {
    const LOGIN_ID = "Your ID";
    const API_KEY  = "Your API Key";

    /* 短縮URLを含むjsonを取得する
     * = example response =
     *   {
     *      "data": {
     *        "global_hash": "900913",
     *        "hash": "ze6poY",
     *        "long_url": "http://google.com/",
     *        "new_hash": 0,
     *        "url": "http://bit.ly/ze6poY"
     *      },
     *      "status_code": 200,
     *      "status_txt": "OK"
     *   }
     */
    public function shorten( $url ) {
        $http = new HttpSocket();
        $response = $http->get($this->shortenReqUrl($url));
        if($response->code != 200) {
            throw new Exception("http_status_error::" . $http_status);
        }
        return json_decode(mb_convert_encoding($response->body, 'UTF-8', 'auto'), true);
    }

    private function shortenReqUrl($url){
        $reqUrl  = "http://api.bit.ly/v3/shorten";
        $reqUrl .= "?login="  .BitlyAPI::LOGIN_ID;
        $reqUrl .= "&apiKey="  .BitlyAPI::API_KEY;
        $reqUrl .= "&longUrl=" .urlencode($url);
        return $reqUrl;
    }
}
?>

BitlyHelper.php

<?php
// app/View/Helper/BitlyHelper.php
App::uses('BitlyAPI', 'Lib');
class BitlyHelper extends Helper {
    function getShortenUrl($url){
        try {
            $api = new BitlyAPI();
            $json = $api->shorten($url);
            if($json['status_code'] != 200 || $json['status_txt'] != 'OK') {
                throw new Exception( sprintf('status_code::%s, errorMessage::%s', $json['status_code'], $json['status_txt']));
            }
        } catch(Exception $e) {
            // 元URLをそのまま表示させる
            return $url;
        }
        return $json['data']['url'];
    }
}
?>