@Qualifier 注解指定装备特定的bean

public interface TestService {
    String test();
}


@Service("aTestService")
public class ATestServiceImpl implements TestService{

    @Override
    public String test() {
        return "A";
    }
}


@Service("bTestService")
public class BTestServiceImpl implements TestService {

    @Override
    public String test() {
        return "B";
    }
}

@RestController
@RequestMapping("/test")
public class TestController {

    @Autowired
    TestServiceImpl testServiceImpl;

    @RequestMapping("/a")// localhost:8080//test/a?type=0
    public String test(int type){
        return testServiceImpl.test(type);
    }
}

@Service
public class TestServiceImpl {

    @Autowired
    @Qualifier("aTestService")
    TestService aTestService;

    @Autowired
    @Qualifier("bTestService")
    TestService bTestService;

    public String  test(int type){
        if (0==type) {
            return aTestService.test();
        }else{
            return bTestService.test();
        }
    }
}

http://localhost:8080//test/a?type=0   结果为A

http://localhost:8080//test/a?type=1   结果为B