Send array of floats as HTTP POST request in php -

i writing script executed client generate array of floats (which understand in php supposed same doubles) , perform post request page take data , compute mean, returning data in response. plan attach send array in message body in json format. found tutorial online doing post requests in php have taken function do_post_request() , can't around following exception:

php fatal error:  uncaught exception 'exception' message 'problem http://localhost/average.php' in /home/yak/restclient.php:20 stack trace: #0 /home/yak/restclient.php(5): do_post_request('http://localhos...', '[1.5,1.5,1.5,1....', 'content-type=ap...') #1 {main}     thrown in /home/yak/restclient.php on line 20 

the client code:

<?php $array = array_fill(0,5,1.5); $data = json_encode($array); echo $data; $response = do_post_request("http://localhost/average.php",$data,"content-type=application/json"); echo $response;  function do_post_request($url, $data, $optional_headers = null) {   $params = array('http' => array(               'method' => 'post',               'content' => $data             ));   if ($optional_headers !== null) {     $params['http']['header'] = $optional_headers;   }   $ctx = stream_context_create($params);   $fp = @fopen($url, 'r', false, $ctx);   if (!$fp) {     throw new exception("problem $url");   }   $response = @stream_get_contents($fp);   if ($response === false) {     throw new exception("problem reading data $url);   }   return $response; } ?> 

would able shed light on error, or better yet, suggest better way of doing i'm trying here? have tried using http_post_data() function, after trying fixes found on so, have been unable work (php sees undefined function).

this server code:

<?php header("content-type:application/json"); if(!empty($_post['data'])) { #calculate mean of each array , send results     $data = $_post['data'];     $array = json_decode($data);     $mean = array_sum($array)/count($array);     respond(200,"ok",$mean); } else { #invalid request     respond(400,"invalid request",null); } function respond($status,$message,$data) {     header("http/1.1 $status $message");     $response['status']=$status;     $response['message']=$message;     $response['data']=$data;     $json_response=json_encode($response);     echo $json_response; } ?> 

this adapted deal several arrays sent in 1 message, started thought quite simple - wrong.

update: using arpita's answer request going through response indicates invalid request, if not doing post.

pretty same other answer, go curl , call function you're doing already, using : instead of = in optional headers as array:

client side

<?php // $url string url send data // $data associative array containing each value want send through post, example: array( 'data', json_encode($array, true) ); // $optional_headers normal array containing strings (key:value, using ":" instead of "="), example: array( 'content-type: application/json' );  function do_post_request($url, $data, $optional_headers) {     $ch = curl_init( $url );      curl_setopt( $ch, curlopt_post, true ); // people use count($data) or 1 instead of true here, according documentation, should true (any number greater 0 evaluate true anyway, it's personal call use 1 or another)     curl_setopt( $ch, curlopt_postfields, serialize($data) );     curl_setopt( $ch, curlopt_returntransfer, true );     curl_setopt( $ch, curlopt_followlocation, true ); // not harmful, follow location: header redirects if server sends them     curl_setopt( $ch, curlopt_httpheader, $optional_headers );      return curl_exec( $ch ); }   $array = array_fill(0,5,1.5); $data = json_encode($array); echo $data; $response = do_post_request("http://localhost/average.php", $data, array('content-type: application/x-www-form-urlencoded', 'accept: application/json')); // note difference: content-type says sending, accept accept answer. you're sending encoded json inside usual form format, content-type html form format instead of json 1 (in other words: you're sending string represents json inside form array) echo $response;  ?> 

to clarify last point (the optional headers content-type), when content-type: application/json should sending json string, mean, example:

[1, 2, 5, 3, 4] (post url-encodes to: %5b1%2c+2%2c+5%2c+3%2c+4%5d)

but you're sending (which content-type: application/x-www-form-urlencoded):

data=[1, 2, 5, 3, 4] (post url-encodes to: data=%5b1%2c+2%2c+5%2c+3%2c+4%5d)

application/x-www-form-urlencoded accepts key-value pairs ones in url.