SNI (Server Name Identification) support for old Apache Commons HTTP Client (for use with Spring Security SAML)

CommonsHttpClientSniSupport.java

import org.apache.commons.httpclient.ConnectTimeoutException;
import org.apache.commons.httpclient.params.HttpConnectionParams;
import org.apache.commons.httpclient.protocol.Protocol;
import org.apache.commons.httpclient.protocol.ProtocolSocketFactory;
import org.apache.commons.httpclient.protocol.ReflectionSocketFactory;
import org.apache.commons.httpclient.protocol.SSLProtocolSocketFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import sun.security.ssl.SSLSocketImpl;

import javax.annotation.PostConstruct;
import javax.net.ssl.SSLSocketFactory;
import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.net.SocketTimeoutException;

/**
 * Enables support for SNI (Server Name Indication) with Apache Commons HTTP Client.
 */
public class CommonsHttpClientSniSupport {

    private Logger logger = LoggerFactory.getLogger(getClass());

    @PostConstruct
    public void enableSniSupport() {
        // note that we're only overriding the createSocket-method that's actually used by the SAML code
        ProtocolSocketFactory sniSupportingSSLProtocolSocketFactory = new SSLProtocolSocketFactory() {
            /**
             * Based on the code in {@link ReflectionSocketFactory#createSocket(java.lang.String, java.lang.String, int, java.net.InetAddress, int, int)}
             * with SNI (Server Name Indication) support added.
             */
            @Override
            public Socket createSocket(String host, int port, InetAddress localAddress, int localPort, HttpConnectionParams params) throws IOException {
                Socket socket = SSLSocketFactory.getDefault().createSocket();
                enableSni(socket, host);
                socket.bind(new InetSocketAddress(localAddress, localPort));
                InetSocketAddress remoteSocketAddress = new InetSocketAddress(InetAddress.getByName(host), port);
                try {
                    socket.connect(remoteSocketAddress, params.getConnectionTimeout());
                    return socket;
                } catch (SocketTimeoutException e) {
                    throw new ConnectTimeoutException(
                            "The host did not accept the connection within timeout of "
                                    + params.getConnectionTimeout() + " ms", e);
                }
            }

            void enableSni(Socket socket, String host) {
                if (socket instanceof SSLSocketImpl) {
                    ((SSLSocketImpl) socket).setHost(host);
                } else {
                    logger.warn("No SNI support since SSLSocket implementation class {} is not supported", socket.getClass().getName());
                }
            }
        };
        Protocol.registerProtocol("https", new Protocol("https", sniSupportingSSLProtocolSocketFactory, 443));
        logger.info("Registered SNI-supporting protocol for HTTPS with Apache Commons HTTP client");
    }
}

How can I use this file in a normal setting like this?

        HttpClient httpclient = HttpClientBuilder.create().build();
        HttpPost httppost = new HttpPost("https://someurl.com");
        HttpResponse response = httpclient.execute(httppost);