下载微信media图片

$this->downWeixinMediaPic($this->getRandStr(),$media_id4);

//jsadk前端上传到微信服务器后， 后端通过media_id拉取图片
    protected function downWeixinMediaPic($pic_name,$media_id){
        $token = $this->getAccessToken();
        $url = "http://file.api.weixin.qq.com/cgi-bin/media/get?access_token=$token&media_id=$media_id";

        $a = file_get_contents($url);
        $filename = $pic_name.'.jpg';//date('YmdHis').rand(1000,9999).'.jpg';
        //以读写方式打开一个文件，若没有，则自动创建
        $mkdir_state = $this->mkdirs_2("/data/xxx/web/files/user/fenghui/".date("Ymd",time()));
        if($mkdir_state){
            $resource = fopen("/data/xxx/web/files/user/fenghui/".date("Ymd",time())."/".$filename, 'w+');

            //将图片内容写入上述新建的文件
            fwrite($resource, $a);
            //关闭资源
            fclose($resource);
            return "/files/user/xxx/".date("Ymd",time())."/".$filename;
        }

    }


 function mkdirs_2($path){
        if(!is_dir($path)){
            $this->mkdirs_2(dirname($path));
            if(!mkdir($path, 0777)){
                return false;
            }
        }
        return true;
    }



   ////微信开始
    private function getAccessToken()
    {
        // access_token 应该全局存储与更新，以下代码以写入到文件中做示例
        $data = json_decode($this->get_php_file("access_token.php"));
        if ($data->expire_time < time()) {
            // 如果是企业号用以下URL获取access_token
            // $url = "https://qyapi.weixin.qq.com/cgi-bin/gettoken?corpid=$this->appId&corpsecret=$this->appSecret";
            $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=wxf4323307315c8f&secret=e66fsd3323481fa2c78d02f807e2";


            //$res = json_decode(file_get_contents($url));
            //$data = json_encode(json_decode( json_encode( $result),true));
            $res = json_decode($this->httpGet($url));

            $access_token = $res->access_token;
            if ($access_token) {
                $data->expire_time = time() + 7000;
                $data->access_token = $access_token;
                $this->set_php_file("access_token.php", json_encode($data));
            }
        } else {
            $access_token = $data->access_token;
        }

        return $access_token;
    }

    private function httpGet($url)
    {

        return file_get_contents($url);
        $curl = curl_init();
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($curl, CURLOPT_TIMEOUT, 500);
        // 为保证第三方服务器与微信服务器之间数据传输的安全性，所有微信接口采用https方式调用，必须使用下面2行代码打开ssl安全校验。
        // 如果在部署过程中代码在此处验证失败，请到 http://curl.haxx.se/ca/cacert.pem 下载新的证书判别文件。
        curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, false);
        curl_setopt($curl, CURLOPT_URL, $url);

        $res = curl_exec($curl);
        curl_close($curl);
        return $res;

        /*
        $res = file_get_contents($url);
        var_dump($res);die();
        return $res;
        */
    }

    private function get_php_file($filename)
    {
        return trim(substr(file_get_contents($filename), 15));
    }

    private function set_php_file($filename, $content)
    {
        $fp = fopen($filename, "w");
        fwrite($fp, "" . $content);
        fclose($fp);
    }