Bean依赖注入注解开发

 

@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  
    @Autowired
    private 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
    @Autowired
    public void cccDao(UserDao userDao) {
        System.out.println("ccc"+userDao);
    }
//    将所有的UserDaoBean都注入到List集合中
     @Autowired
    public  void  bbb(List 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;