follow codes is php code ,but it don't download anything.
$postdata=$jsonstr;
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
'Content-Type: application/json',
//'Content-Type: application/x-www-form-urlencoded"',
'Content-Length: ' . strlen($postdata)
));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, $postdata );
$output = curl_exec($ch);
$info = curl_getinfo($ch);
echo "<br/>-------------------<br/>";
//print_r($output);
echo "<br/>-------------------<br/>";
mySaveFile($output, "./file.tmp");
curl_close($ch);
I get 'file.tmp' always is size 0.I suspect I set up a mistake for CURLOPT_HTTPHEADER, thanks for everyone help.