private function http_curl($url,$data=null){

//1.初始化，创建一个新cURL资源

$ch = curl_init();

//2.设置URL和相应的选项

curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch,CURLOPT_SSL_VERIFYPEER,FALSE);
curl_setopt($ch,CURLOPT_SSL_VERIFYHOST,FALSE);
//curl_setopt($ch, CURLOPT_HEADER, 0);
if(!empty($data)){
curl_setopt($ch,CURLOPT_POST,1);
curl_setopt($ch,CURLOPT_POSTFIELDS,$data);
}

curl_setopt($ch,CURLOPT_RETURNTRANSFER,1);//禁止curl资源直接输出
//3.抓取URL并把它传递给浏览器
$opt=curl_exec($ch);
//4.关闭cURL资源，并且释放系统资源
curl_close($ch);
return $opt;
}