PHP发送JSON

$curl = curl_init();
curl_setopt_array($curl, array(
  CURLOPT_URL => 'http://114.55.100.196:21632/api',
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => '',
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 0,
  CURLOPT_FOLLOWLOCATION => true,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => 'POST',
  CURLOPT_POSTFIELDS =>'{"type":1001}',
  CURLOPT_HTTPHEADER => array(
    'Content-Type: text/plain'
  ),
));
$response = curl_exec($curl);
curl_close($curl);
echo $response;

　　PHP发送JSON