Spring Web controller that produces TwiML for creating a conference call

IncomingCallWebhook.java

package lol.gilliard.conferencecalls;

import com.twilio.twiml.VoiceResponse;
import com.twilio.twiml.voice.Conference;
import com.twilio.twiml.voice.Dial;
import com.twilio.twiml.voice.Say;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
public class IncomingCallWebhook {

    private static String CONFERENCE_ROOM_NAME = "my-conference-room";

    @PostMapping(value = "/call", produces = "text/xml")
    @ResponseBody
    public String generateTwiml(){
        return new VoiceResponse.Builder()
            .say(new Say.Builder("Hold tight, we're connecting you to the conference call").build())
            .dial(new Dial.Builder()
                .conference(new Conference.Builder(CONFERENCE_ROOM_NAME).build())
                .build())
            .build().toXml();
    }
}