- SpringBoot项目中可能出现一个接口有多个实现类的情况,如果不进行配置,注入接口时编译器不知道要注入哪个实现类就会报错,因此需要进行配置。以下进行举例:
- 接口如下:
public interface NoticeService {
public String noticeUser(Long id);
}
- 两个实现类如下:
@Service
public class NoticeServiceImpl1 implements NoticeService {
public String noticeUser(Long id){
return noticeServe1(id);
}
}
@Service
public class NoticeServiceImpl2 implements NoticeService {
public String noticeUser(Long id){
return noticeServe2(id);
}
}
- Controller如下:
@Controller
@RequestMapping("notice")
public class NoticeController{
@Autowired
NoticeService noticeService;
}
- 这样直接启动后就会报错,需要在添加@Qualifier注解:
@Controller
@RequestMapping("notice")
public class NoticeController{
@Autowired
@Qualifier("impl1")
NoticeService noticeService;
}
- 需要调用的实现类中添加标识:
@Service("impl1")
public class NoticeServiceImpl1 implements NoticeService {
public String noticeUser(Long id){
return noticeServe1(id);
}
}
此时再运行即可