ChatRoom.java

package u025;

import java.util.HashMap;
import java.util.Map;
import u023.v2.ICommand;

/**
 * Concrete Mediator
 * Created by HuGuodong on 12/8/19.
 */
public class ChatRoom implements IChatRoom {

 private Map<String, User> userMap = new HashMap<>();

 @Override
 public void sendMessage(String msg, String userid) {
 User user = userMap.get(userid);
 user.receive(msg);
 }

 @Override
 public void addUser(User user) {
 userMap.put(user.getId(), user);
 }
}