[php]通过http post发送json数据

function http_post_data($url, $data_string) {

$ch = curl_init();
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_POSTFIELDS, $data_string);
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
'Content-Type: application/json; charset=utf-8',
'Content-Length: ' . strlen($data_string))
);
ob_start();
curl_exec($ch);
$return_content = ob_get_contents();
ob_end_clean();

$return_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
return array($return_code, $return_content);
}

$url  = "http://xx.xx.cn";
$data = json_encode(array('a'=>1, 'b'=>2));

list($return_code, $return_content) = http_post_data($url, $data);