# @Qualifier
- BookDaoImpl
@SuppressWarnings("all") | |
@Repository("bookDao1") | |
public class BookDaoImpl implements BookDao { | |
public void save(){ | |
System.out.println("BookDaoImpl save rning..."); | |
} | |
} |
- BookDaoImpl1
@SuppressWarnings("all") | |
@Repository("bookDao") | |
public class BookDaoImpl1 implements BookDao { | |
public void save(){ | |
System.out.println("BookDaoImpl save rning... 1"); | |
} | |
} |
- BookServiceImpl
@SuppressWarnings("all") | |
@Service("bookService") | |
public class BookServiceImpl implements BookService { | |
@Autowired | |
@Qualifier("bookDao") | |
private BookDao bookDao ; | |
public void save(){ | |
System.out.println("BookServiceImpl save rning..."); | |
bookDao.save(); | |
} | |
} |
<font style="color:red"> 注意:</font> 需要使用 @Autowired 不然就会报错
- 演示不使用 @Autowired
@SuppressWarnings("all") | |
@Service("bookService") | |
public class BookServiceImpl implements BookService { | |
@Qualifier("bookDao") | |
private BookDao bookDao; | |
public void save(){ | |
System.out.println("BookServiceImpl save rning..."); | |
bookDao.save(); | |
} | |
} |
Run Result
在 @Qualifier 参数列表中指定两个 Dao 其中一个名称则 Run 结果为其该 bean 的 save 方法内容
- BookServiceImpl
@SuppressWarnings("all") | |
@Service("bookService") | |
public class BookServiceImpl implements BookService { | |
@Autowired | |
@Qualifier("bookDao") | |
private BookDao bookDao; | |
public void save(){ | |
System.out.println("BookServiceImpl save rning..."); | |
bookDao.save(); | |
} | |
} |
Run Result
- BookServiceImpl
@SuppressWarnings("all") | |
@Service("bookService") | |
public class BookServiceImpl implements BookService { | |
@Autowired | |
@Qualifier("bookDao1") | |
private BookDao bookDao; | |
public void save(){ | |
System.out.println("BookServiceImpl save rning..."); | |
bookDao.save(); | |
} | |
} |
Run Result
