Включить аннотацию Singleton в веб-проект IntelliJ Java

Question

Создание веб-приложения в IntelliJ IDE с сервером GlassFish в соответствии с руководством .

IntelliJ жалуется на Cannot resolve symbol Singleton и Cannot resolve symbol inject в приведенном ниже коде:

import java.util.Collections;
import java.util.HashSet;
import java.util.Set;
import javax.inject.Singleton; // Cannot resolve symbol inject
import javax.websocket.OnClose;
import javax.websocket.OnMessage;
import javax.websocket.Session;
import javax.websocket.OnOpen;
import javax.websocket.server.ServerEndpoint;

    @ServerEndpoint(value="/chat")
    @Singleton //Cannot resolve symbol Singleton
    public class ChatServerEndPoint {

        Set<Session> userSessions = Collections.synchronizedSet(new HashSet<Session>());

        /**
         * Callback hook for Connection open events.
         *
         * This method will be invoked when a client requests for a
         * WebSocket connection.
         *
         * @param userSession the userSession which is opened.
         */
        @OnOpen
        public void onOpen(Session userSession) {
            System.out.println("New request received. Id: " + userSession.getId());
            userSessions.add(userSession);
        }

        /**
         * Callback hook for Connection close events.
         *
         * This method will be invoked when a client closes a WebSocket
         * connection.
         *
         * @param userSession the userSession which is opened.
         */
        @OnClose
        public void onClose(Session userSession) {
            System.out.println("Connection closed. Id: " + userSession.getId());
            userSessions.remove(userSession);
        }

        /**
         * Callback hook for Message Events.
         *
         * This method will be invoked when a client send a message.
         *
         * @param message The text message
         * @param userSession The session of the client
         */
        @OnMessage
        public void onMessage(String message, Session userSession) {
            System.out.println("Message Received: " + message);
            for (Session session : userSessions) {
                System.out.println("Sending to " + session.getId());
                session.getAsyncRemote().sendText(message);
            }
        }
    }

Как решить эту проблему?Как включить необходимую библиотеку в мой проект?