微信授权获取用户的openid

<?php 
/**  
* Created by PhpStorm.  
* User: Administrator  
* Date: 2016/8/9  
* Time: 15:31 
 */ 
 echo "<meta name=\"viewport\" content=\"width=device-width, 
 initial-scale=1, maximum-scale=1, user-scalable=no\">"; 
 $code = $_GET['code'];
  //echo "code: "; 
  //echo $code; 
  $getAccess = new getWxAccess(); 
  $getAccess->getCode(); 
  class getWxAccess{    
  public function __construct()    
  {      
  }   
   public function getCode(){        
   $appid = 'wx8109981b74f329f6';        
   $secret = 'd5cc4a9838959c3bd6f814ed79afd811';       
    $code = $_GET['code'];        
$url = " 
appid=$appid&secret=$secret&code=$code&grant_type=authorization_code"; 
//       
echo $url;        
$ch = curl_init();        
curl_setopt($ch, CURLOPT_URL,$url );        
curl_setopt($ch, CURLOPT_RETURNTRANSFER,1 );        
$res = curl_exec($ch);        
curl_close($ch); 
//       
if(curl_error($ch)){ 
//           
var_dump(curl_error($ch)); 
//       
}        
$arr = json_decode($res , true);        
//得到access_token 
//       
var_dump($arr); //       
echo $arr["access_token"];        
$this -> getUserInfo($arr["access_token"],$arr["openid"]);    
}         
public function getUserInfo($accessToken , $openid){         
$url = " 
 $ch = curl_init();         
 curl_setopt($ch, CURLOPT_URL,$url );         
 curl_setopt($ch, CURLOPT_RETURNTRANSFER,1 );         
 $res = curl_exec($ch);         
 curl_close($ch); 
 //       
 if(curl_error($ch)){ 
 //           
 var_dump(curl_error($ch)); 
 //       
 }         
 $arr = json_decode($res , true);         
 //获取用户信息 
 //        
 var_dump($arr);         
 echo "<h1>用户名：".$arr['nickname']."</h1>";         
 echo "<h1>头像：<img style='width: 10%;text-align: center' src=".$arr['headimgurl']."></h1>";
 if($arr['sex'] == '1'){             
 $arr['sex'] = '男';         
 }else{             
 $arr['sex'] ='女';         
 }         
 echo "<h2>性别：".$arr['sex']."</h2>";         
 echo "<h3>国家：".$arr['country']."</h3>";        
 } } ?>