@value

    @Value("xfy")private String userName;private String userName;@Value("xiao")public void setUserName(String userName) {this.userName = userName;}

 

 

@Autowired

//    根据类型进行注入 如果同一类型的Bean有多个，尝试根基名字进行二次匹配  @Autowiredprivate UserDao userDao;public void setUserDao(UserDao userDao) {this.userDao = userDao;}

 

//    表示@Autowired   使用在方法上不一定要是set方法@Autowiredpublic void cccDao(UserDao userDao) {System.out.println("ccc"+userDao);}
//    将所有的UserDaoBean都注入到List集合中@Autowiredpublic  void  bbb(List<UserDao> userDaoList){System.out.println("bbb"+userDaoList);}

 

@Qualifier

//    根据类型进行注入 如果同一类型的Bean有多个，尝试根基名字进行二次匹配
//    @Qualifier允许与@Autowired结合使用，使得根据名称注入@Autowired@Qualifier("userDao")private UserDao userDao;public void setUserDao(UserDao userDao) {this.userDao = userDao;}public void show() {System.out.println(userDao);}

 

@Resource

  @Resource(name = "userDao")private UserDao userDao;