php使用curl提交xml数据

 $xml_data ='<xml>
   <return_code><![CDATA[SUCCESS]]></return_code>
   <return_msg><![CDATA[OK]]></return_msg>
 </xml>
 ';

             $URL = "http://localhost/aa.php";
             $ch = curl_init($URL);
             curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
             curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0); //禁用后cURL将终止从服务端进行验证
             curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: text/xml'));   //设置header
             curl_setopt($ch, CURLOPT_POST, 1);                                       //post提交方式
             curl_setopt($ch, CURLOPT_POSTFIELDS, "$xml_data");
             curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);  //将curl_exec()获取的信息以文件流的形式返回，而不是直接输出
             $data = curl_exec($ch);
             if($data){
                 curl_close($ch);
                 echo($data);
              }
              else{
                 $error = curl_errno($ch);
                 curl_close($ch);
                 echo("curl出错，错误码:$error");
              }

 <?php
 echo "<pre>";
 var_dump($_POST);
 $data = file_get_contents('php://input');   //都要解下码
 var_dump(($data));
 echo "<br>";
 var_dump(($GLOBALS['HTTP_RAW_POST_DATA']));
 ?>