检测是否是手机访问接口

/**
 * 检测是否使用手机访问
 * @access public
 * @return bool
 */
public function isMobile()
{
    if (isset($_SERVER['HTTP_VIA']) && stristr($_SERVER['HTTP_VIA'], "wap")) {
        return true;
    } elseif (isset($_SERVER['HTTP_ACCEPT']) && strpos(strtoupper($_SERVER['HTTP_ACCEPT']), "VND.WAP.WML")) {
        return true;
    } elseif (isset($_SERVER['HTTP_X_WAP_PROFILE']) || isset($_SERVER['HTTP_PROFILE'])) {
        return true;
    } elseif (isset($_SERVER['HTTP_USER_AGENT']) && preg_match('/(blackberry|configuration\/cldc|hp |hp-|htc |htc_|htc-|iemobile|kindle|midp|mmp|motorola|mobile|nokia|opera mini|opera |Googlebot-Mobile|YahooSeeker\/M1A1-R2D2|android|iphone|ipod|mobi|palm|palmos|pocket|portalmmm|ppc;|smartphone|sonyericsson|sqh|spv|symbian|treo|up.browser|up.link|vodafone|windows ce|xda |xda_|okhttp)/i', $_SERVER['HTTP_USER_AGENT'])) {
        return true;
    } else {
        return false;
    }
}