php ftp类

class FTPClient {
    private $connId;

    public function __construct($host, $username, $password, $port = 21) {
        $this->connId = ftp_connect($host, $port);
        if (!$this->connId) {
            throw new Exception("Could not connect to $host");
        }
        if (!ftp_login($this->connId, $username, $password)) {
            ftp_close($this->connId);
            throw new Exception("Could not login to $host");
        }
    }

    public function upload($localFile, $remoteFile) {
        if (!ftp_put($this->connId, $remoteFile, $localFile, FTP_BINARY)) {
            throw new Exception("Could not upload $localFile");
        }
    }

    public function download($remoteFile, $localFile) {
        if (!ftp_get($this->connId, $localFile, $remoteFile, FTP_BINARY)) {
            throw new Exception("Could not download $remoteFile");
        }
    }

    public function close() {
        ftp_close($this->connId);
    }
}

// 使用示例
try {
    $ftp = new FTPClient('ftp.example.com', 'username', 'password');
    $ftp->upload('local.txt', 'remote.txt');
    $ftp->download('remote.txt', 'local_downloaded.txt');
    $ftp->close();
} catch (Exception $e) {
    echo $e->getMessage();
}