PHP handles WeChat SDK interception of photo uploads

namespace Home\Controller;
use Think\Controller;
use  app\common\Curl;
class ParentController extends Controller
{
    public function __construct(){
        parent::__construct();
        $this->appId = '你的appid';
        $this->appSecret = '你的appSecret';
        $openid = session('openid');
        // session("openid",'ogC7U1XRM3ZOqjLZ99O2coJjYsrU');
        if(!$openid){
            $this->get_openid();
        }
    }

/**
     * 给客户端返回必要微信参数
     * @Author   TGHan
     * @DateTime 2018-04-26
     * @return   [type]     [description]
     */
    public function modifyinfor() {
        $jsapiTicket = $this->getJsApiTicket();
        // 注意 URL 一定要动态获取，不能 hardcode.
        $protocol = (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off' || $_SERVER['SERVER_PORT'] == 443) ? "https://" : "http://";
        $url = "$protocol$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";
        $timestamp = time();
        $nonceStr = $this->createNonceStr();
        // 这里参数的顺序要按照 key 值 ASCII 码升序排序
        $string = "jsapi_ticket=$jsapiTicket&noncestr=$nonceStr&timestamp=$timestamp&url=$url";
        $signature = sha1($string);
        $signPackage = array(
          "appId"     => $this->appId,
          "nonceStr"  => $nonceStr,
          "timestamp" => $timestamp,
          "url"       => $url,
          "signature" => $signature,
          "rawString" => $string
        );
        $this->assign('signPackage',$signPackage);
        $this->display();
    }


    public function createNonceStr($length = 16) {
        $chars ="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
        $str = "";
        for ($i = 0; $i < $length; $i++) {
            $str .= substr($chars, mt_rand(0, strlen($chars) - 1), 1);
        }
        return $str;
    }


    public function getJsApiTicket() {
        // jsapi_ticket 应该全局存储与更新，以下代码以写入到文件中做示例
        $data =json_decode(file_get_contents("jsapi_ticket.json"));
        if ($data->expire_time < time()) {
            $accessToken = $this->getAccessToken();
            // 如果是企业号用以下 URL 获取 ticket
            // $url = "https://qyapi.weixin.qq.com/cgi-bin/get_jsapi_ticket?access_token=$accessToken";
            $url = "https://api.weixin.qq.com/cgi-bin/ticket/getticket?type=jsapi&access_token=$accessToken";
            $res = json_decode($this->httpGet($url));
            $ticket = $res->ticket;
            if ($ticket) {
                $data->expire_time = time() + 7000;
                $data->jsapi_ticket = $ticket;
                $fp = fopen("jsapi_ticket.json", "w");
                fwrite($fp, json_encode($data));
                fclose($fp);
            }
        } else {
            $ticket = $data->jsapi_ticket;
        }
        return $ticket;
    }


    public 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
        $data =json_decode(file_get_contents("access_token.json"));
        if ($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";
            $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=$this->appId&secret=$this->appSecret";
            $res = json_decode($this->httpGet($url));
            $access_token = $res->access_token;
            if ($access_token) {
                $data->expire_time = time() + 7000;
                $data->access_token = $access_token;
                $fp = fopen("access_token.json", "w");
                fwrite($fp, json_encode($data));
                fclose($fp);
            }
        } else {
            $access_token = $data->access_token;
        }
        return $access_token;
    }


    public function httpGet($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, true);
        curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, true);
        curl_setopt($curl, CURLOPT_URL, $url);


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


        return $res;
    }

/*图片
    * 获取media_id 
    */  
    public function upload_head(){  
        if(IS_POST){  
            $serverId = I('post.media_id');  
            if(!empty($serverId)){  
                $news_file = $this->doWechatPic( $serverId );
                $this->ajaxReturn(array("is_success"=>"success","msg"=>"上传成功","url"=>$news_file));
            }else{
                $this->ajaxReturn(array("is_success"=>"error","msg"=>"上传失败1"));
            }
        } 
    }  


    /* 
    * 从微信服务器获取图片流 
    */  
    public function doWechatPic($serverId){//media_id=jlJs_iQIOA-TKLuhk4nCdPEdXnJ6paIeToO8vr-WUGvz05-6i5n498EzI232xSxn  
        $media_id = $serverId;//提交过来的serverId即$media_id     
        $access_token = $this->getAccessToken();
        $pic_url = "http://file.api.weixin.qq.com/cgi-bin/media/get?access_token={$access_token}&media_id={$media_id}";  
        $filebody = file_get_contents($pic_url);//通过接口获取图片流  
        $filename = date("Ymd").'_'.uniqid().'.jpg';//定义图片名字及格式  
        return $this->saveFile($filename, $filebody);  
    }  


    /* 
    * 定义文件路径，写入图片流 
    */  
    public function saveFile($filename, $filecontent){  
        $upload_dir = "./Public/static/images/headers";//保存路径，以时间作目录分层  
        $mkpath = $upload_dir;          
        if(!is_dir($mkpath)){  
            if(!mkdir($mkpath)){  
                die('no mkdir power');  
            }  
            if(!chmod($mkpath,0755)){//若服务器在阿里云上不建议使用0644  
                die('no chmod power');  
            }  
        }
        $savepath = $upload_dir.'/'.$filename;       
        if(file_put_contents($savepath, $filecontent)){//写入图片流生成图片
            $news_file = substr($savepath,1);
            return $news_file;//返回图片路径  
        }else{  
            die('save failed');  
        }  


    }

public function save_child(){
        $openid = session("openid");
        $class_tid = session("class_tid");
        if(IS_POST){
            $data = array();
            $data['cd_head'] = I('post.cd_head') ? I('post.cd_head') : '';
            $data['cd_name'] = I('post.cd_name') ? I('post.cd_name') : '';
            $data['cd_birthday'] = I('post.cd_birthday') ? I('post.cd_birthday') : '';
            $data['cd_sex'] = I('post.cd_sex') ? I('post.cd_sex') : '';
            $editData = M("parent_child")->where("class_tid='{$class_tid}' and wx_openid='{$openid}'")->save($data);
            if($editData !== false){
                $this->ajaxReturn(array("is_success"=>"success","msg"=>"修改成功"));
            }else{
                $this->ajaxReturn(array("is_success"=>"error","msg"=>"修改失败"));
            }
        }
    }