PHP+CURL+GET传输json请求数据

/**
$url 访问地址
$postfields 请求参数（json字符串）
$headers 请求头
*/
function httpCurl($url, $postfields = '', $headers =['Content-Type:application/json;charset=UTF-8'])
{

    $ci = curl_init();
    curl_setopt($ci, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ci, CURLOPT_CONNECTTIMEOUT, 50);
    curl_setopt($ci, CURLOPT_TIMEOUT, 600);
    curl_setopt($ci, CURLOPT_HTTPHEADER, $headers);
    curl_setopt($ci, CURLOPT_URL, $url);

    curl_setopt($ci, CURLOPT_SSL_VERIFYPEER, false);
    curl_setopt($ci, CURLOPT_SSL_VERIFYHOST, false);

    curl_setopt($ci, CURLOPT_CUSTOMREQUEST, 'GET' );
    curl_setopt($ci, CURLOPT_POSTFIELDS, $postfields);
    $response = curl_exec($ci);
    curl_close($ci);

    return $response;
}