这里明明有两个UserDao的实现类，且实现类没有做任何处理，为什么没有出现老师视频里的错误

IUserDao接口类

package com.imooc.spring.ioc.dao;

public interface IUserDao {
}

UserDao类

package com.imooc.spring.ioc.dao;

import org.springframework.context.annotation.Primary;
import org.springframework.stereotype.Repository;
//组件类型注解默认beanId为类名首字母小写
//beadId = userDao
@Repository
public class UserDao implements IUserDao{
    public UserDao(){
        System.out.println("正在创建UserDao:" + this);
    }
}

UserOracleDao类

package com.imooc.spring.ioc.dao;

import org.springframework.context.annotation.Primary;
import org.springframework.stereotype.Repository;

@Repository
public class UserOracleDao implements IUserDao {
    public UserOracleDao(){
        System.out.println("正在创建UserOracleDao:" + this);
    }
}

UserService类

package com.imooc.spring.ioc.service;

import com.imooc.spring.ioc.dao.IUserDao;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class UserService {

    public UserService(){
        System.out.println("正在创建UserService:" + this);
    }
    @Autowired
    private IUserDao userDao;

    public IUserDao getUserdao() {
        return userDao;
    }

//    public void setUserDao(IUserDao userDao) {
//        System.out.println("setUdao:" + userDao);
//        this.userDao = userDao;
//    }
}

SpringApplication类

package com.imooc.spring.ioc;

import com.imooc.spring.ioc.service.UserService;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class SpringApplication {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("classpath:applicationContext.xml");
//        String[] ids = context.getBeanDefinitionNames();
//        for(String id :ids){
//            System.out.println(id+":"+context.getBean(id));
//        }

        UserService userService = context.getBean("userService", UserService.class);
        System.out.println(userService.getUserdao());
    }


}

运行结果：

两个实现类被同时创建了