注解@Autowired

功能 :

１、可对类成员变量及方法入参进行标注

@Service

public class LoginService {

@Autowied

   private LogDao logDao;

@Autowired

   private UserDao userDao;

@Autowired

   public void setLogDao(LogDao logDao) {

       this.logDao=logDao;

   }

@Autowired

@Qualifier("userDao")

   public void setUserdao(UserDao userDao) {

       this.userDao=userDao;

   }

@Autowired

   public void init(@Qualifier("userDao") UserDao userDao, LogDao logDao) {}

}

２、对集合类进行标注

public class MyComponent {

@Autowired

   private List plugins;    //Plugin 是接口

}

如果有Plugin的子实现类p1,p2,p3(都被@Component标注)

注入的时候会将p1,p2,p3作为元素注入到plugins集合中

@Autowired    按类型匹配

@Resource    按名称匹配