/**
* 發(fā)送HTTP請求方法，目前只支持CURL發(fā)送請求
* @param string $url  請求URL
* @param array $params 請求參數(shù)
* @param string $method 請求方法GET/POST
* @return array $data  響應數(shù)據(jù)
*/
protected function http($url, $params, $method = 'GET', $header = array(), $multi = false) {
    $opts = array(CURLOPT_TIMEOUT => 30, CURLOPT_RETURNTRANSFER => 1, CURLOPT_SSL_VERIFYPEER => false, CURLOPT_SSL_VERIFYHOST => false, CURLOPT_HTTPHEADER => $header);
    /* 根據(jù)請求類型設置特定參數(shù) */
    switch(strtoupper($method)) {
      case 'GET' :
        $opts[CURLOPT_URL] = $url . '&' . http_build_query($params);
        dump($opts[CURLOPT_URL]);
        break;
      case 'POST' :
        //判斷是否傳輸文件
        $params = $multi ? $params : http_build_query($params);
        $opts[CURLOPT_URL] = $url;
        dump($opts[CURLOPT_URL]);
        $opts[CURLOPT_POST] = 1;
        $opts[CURLOPT_POSTFIELDS] = $params;
        break;
      default :
        throw new Exception('不支持的請求方式！');
    }
    /* 初始化并執(zhí)行curl請求 */
    $ch = curl_init();
    curl_setopt_array($ch, $opts);
    $data = curl_exec($ch);
    $error = curl_error($ch);
    curl_close($ch);
    if ($error)
      throw new Exception('請求發(fā)生錯誤：' . $error);
    return $data;
}