*/
public static void removeUserEntity(String userId) {
IoSession session = userEntitySessions.remove(userId); // ���ISession���û�����
session = null;
UserEntity userEntity = userEntities.remove(userId); // �Ƴ���ǰ�û�ģ��
String userName = userEntity.getUserName();
userEntity = null;
userEntity = userEntitynames.remove(userName);
userEntity = null;
System.out.println("XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX");