cURL操作可以在API服务器端代码中进行吗?

我看到一个示例服务器端API有cURL操作，我认为cURL应该是客户端请求。下面的类API是服务器端代码，但继承自网络类，它有一堆uCurls操作。

类Api扩展Api'Network

abstract class Network {
const GET  = 'GET';
const POST = 'POST';
const HTTP_OK      = 200;
const HTTP_CREATED = 201;
protected function curl($type, $url, $queryString = array())
{
    $s = curl_init();
    switch (strtoupper($type)) {
        case self::POST:
            echo "$url'n";
            echo 'http_build_query($queryString) . "'n";
                die();
            curl_setopt($s, CURLOPT_URL, $url);
            curl_setopt($s, CURLOPT_POST, true);
            curl_setopt($s, CURLOPT_POSTFIELDS, $queryString);
            break;
        case self::GET:
            curl_setopt($s, CURLOPT_URL, $url . '?' .

http_build_query($变量));打破;}

    curl_setopt($s, CURLOPT_RETURNTRANSFER, true);
    $_out = curl_exec($s);
    $status = curl_getinfo($s, CURLINFO_HTTP_CODE);
    curl_close($s);
    switch ($status) {
        case self::HTTP_OK:
        case self::HTTP_CREATED:
            $out = $_out;
            break;
        default:
            throw new 'Exception("http error: {$status}",

美元地位);}返回$;}}