public void setProtocols(java.util.Collection<String> protocols) {
        if (protocols == null) {
            this.protocols = null;
            return;
        }

        this.protocols = new java.util.ArrayList<String>(protocols);
    }
<p>
Specifies the file transfer protocol or protocols over which your file transfer protocol client can connect to
your server's endpoint. The available protocols are:
</p>
<ul>
<li>
<p>
<code>SFTP</code> (Secure Shell (SSH) File Transfer Protocol): File transfer over SSH
</p>
</li>
<li>
<p>
<code>FTPS</code> (File Transfer Protocol Secure): File transfer with TLS encryption
</p>
</li>
<li>
<p>
<code>FTP</code> (File Transfer Protocol): Unencrypted file transfer
</p>
</li>
<li>
<p>
<code>AS2</code> (Applicability Statement 2): used for transporting structured business-to-business data
</p>
</li>
</ul>
<note>
<ul>
<li>
<p>
If you select <code>FTPS</code>, you must choose a certificate stored in Certificate Manager (ACM) which is used
to identify your server when clients connect to it over FTPS.
</p>
</li>
<li>
<p>
If <code>Protocol</code> includes either <code>FTP</code> or <code>FTPS</code>, then the
<code>EndpointType</code> must be <code>VPC</code> and the <code>IdentityProviderType</code> must be either
<code>AWS_DIRECTORY_SERVICE</code>, <code>AWS_LAMBDA</code>, or <code>API_GATEWAY</code>.
</p>
</li>
<li>
<p>
If <code>Protocol</code> includes <code>FTP</code>, then <code>AddressAllocationIds</code> cannot be associated.
</p>
</li>
<li>
<p>
If <code>Protocol</code> is set only to <code>SFTP</code>, the <code>EndpointType</code> can be set to
<code>PUBLIC</code> and the <code>IdentityProviderType</code> can be set any of the supported identity types:
<code>SERVICE_MANAGED</code>, <code>AWS_DIRECTORY_SERVICE</code>, <code>AWS_LAMBDA</code>, or
<code>API_GATEWAY</code>.
</p>
</li>
<li>
<p>
If <code>Protocol</code> includes <code>AS2</code>, then the <code>EndpointType</code> must be <code>VPC</code>,
and domain must be Amazon S3.
</p>
</li>
</ul>
</note>

@param protocols
       Specifies the file transfer protocol or protocols over which your file transfer protocol client can
       connect to your server's endpoint. The available protocols are:</p>
       <ul>
       <li>
       <p>
       <code>SFTP</code> (Secure Shell (SSH) File Transfer Protocol): File transfer over SSH
       </p>
       </li>
       <li>
       <p>
       <code>FTPS</code> (File Transfer Protocol Secure): File transfer with TLS encryption
       </p>
       </li>
       <li>
       <p>
       <code>FTP</code> (File Transfer Protocol): Unencrypted file transfer
       </p>
       </li>
       <li>
       <p>
       <code>AS2</code> (Applicability Statement 2): used for transporting structured business-to-business data
       </p>
       </li>
       </ul>
       <note>
       <ul>
       <li>
       <p>
       If you select <code>FTPS</code>, you must choose a certificate stored in Certificate Manager (ACM) which
       is used to identify your server when clients connect to it over FTPS.
       </p>
       </li>
       <li>
       <p>
       If <code>Protocol</code> includes either <code>FTP</code> or <code>FTPS</code>, then the
       <code>EndpointType</code> must be <code>VPC</code> and the <code>IdentityProviderType</code> must be
       either <code>AWS_DIRECTORY_SERVICE</code>, <code>AWS_LAMBDA</code>, or <code>API_GATEWAY</code>.
       </p>
       </li>
       <li>
       <p>
       If <code>Protocol</code> includes <code>FTP</code>, then <code>AddressAllocationIds</code> cannot be
       associated.
       </p>
       </li>
       <li>
       <p>
       If <code>Protocol</code> is set only to <code>SFTP</code>, the <code>EndpointType</code> can be set to
       <code>PUBLIC</code> and the <code>IdentityProviderType</code> can be set any of the supported identity
       types: <code>SERVICE_MANAGED</code>, <code>AWS_DIRECTORY_SERVICE</code>, <code>AWS_LAMBDA</code>, or
       <code>API_GATEWAY</code>.
       </p>
       </li>
       <li>
       <p>
       If <code>Protocol</code> includes <code>AS2</code>, then the <code>EndpointType</code> must be
       <code>VPC</code>, and domain must be Amazon S3.
       </p>
       </li>
       </ul>
@see Protocol
aws-java-sdk-transfer/src/main/java/com/amazonaws/services/transfer/model/UpdateServerRequest.java