UnsatisfiedDependencyException：使用名称创建bean时出错

Question

几天来，我一直在尝试创建Spring CRUD应用程序。我糊涂了。我无法解决此错误。

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'clientController': Unsatisfied dependency expressed through method 'setClientService' parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'clientService': Unsatisfied dependency expressed through field 'clientRepository'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.kopylov.repository.ClientRepository' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}

还有这个

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'clientService': Unsatisfied dependency expressed through field 'clientRepository'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.kopylov.repository.ClientRepository' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}

客户端控制器

@Controller
public class ClientController {
private ClientService clientService;

@Autowired
@Qualifier("clientService")
public void setClientService(ClientService clientService){
    this.clientService=clientService;
}
@RequestMapping(value = "registration/add", method = RequestMethod.POST)
public String addUser(@ModelAttribute Client client){
    this.clientService.addClient(client);
return "home";
}
}

ClientServiceImpl

@Service("clientService")
public class ClientServiceImpl implements ClientService{

private ClientRepository clientRepository;

@Autowired
@Qualifier("clientRepository")
public void setClientRepository(ClientRepository clientRepository){
    this.clientRepository=clientRepository;
}



@Transactional
public void addClient(Client client){
    clientRepository.saveAndFlush(client);
}
}

客户资料库

public interface ClientRepository extends JpaRepository<Client, Integer> {

}

我浏览了许多类似的问题，但是没有人回答不能帮助我。

Answer 1

ClientRepository应该用@Repository标记注释。使用你当前的配置，Spring将不会扫描该类并对其有所了解。在启动和连接时，找不到ClientRepository类。

编辑 如果添加@Repository标签没有帮助，那么我认为问题可能出在ClientServiceand ClientServiceImpl。

尝试用注释ClientService（接口）@Service。由于你应该只为服务提供一个实现，因此不需要使用optional参数指定名称@Service("clientService")。Spring将根据接口名称自动生成它。

另外，如Bruno所述，由于你只有该服务的单个实现，因此@Qualifier不需要ClientController。

ClientService.java

@Service
public interface ClientService {

    void addClient(Client client);
}

ClientServiceImpl.java（选项1）

@Service
public class ClientServiceImpl implements ClientService{

    private ClientRepository clientRepository;

    @Autowired
    public void setClientRepository(ClientRepository clientRepository){
        this.clientRepository=clientRepository;
    }

    @Transactional
    public void addClient(Client client){
        clientRepository.saveAndFlush(client);
    }
}

ClientServiceImpl.java（选项2 /首选）

@Service
public class ClientServiceImpl implements ClientService{

    @Autowired
    private ClientRepository clientRepository;

    @Transactional
    public void addClient(Client client){
        clientRepository.saveAndFlush(client);
    }
}

ClientController.java

@Controller
public class ClientController {
    private ClientService clientService;

    @Autowired
    //@Qualifier("clientService")
    public void setClientService(ClientService clientService){
        this.clientService=clientService;
    }

    @RequestMapping(value = "registration", method = RequestMethod.GET)
    public String reg(Model model){
        model.addAttribute("client", new Client());
        return "registration";
    }

    @RequestMapping(value = "registration/add", method = RequestMethod.POST)
    public String addUser(@ModelAttribute Client client){
        this.clientService.addClient(client);
    return "home";
    }
}