@Autowired @Qualifier("userDao") to be used with

By default, @Autowired looks for a matching bean in the container by type matching. If there is only one matching bean, Spring injects it into the variable marked by @Autowired . If there is more than one matching bean in the container, the bean name can be qualified by the @Qualifier annotation. For example:
@Service
public class LoginService
{
@Autowired
@Qualifier ("userDao")
private UserDao userDao; //here
}
Assuming that there are two beans of type UserDao in the container, one named userDao and the other named otherUserDao , then The bean injected "here" above is the userDao.