NoSuchBeanDefinition异常

Question

我在尝试运行Spring启动应用程序时遇到以下错误没有这样的bean定义异常。请让我知道我错过了什么。它是一个简单的弹簧框架，但我遇到了这个错误。任何帮助表示赞赏。

Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.cnanational.servicecommon.validation.Validator<com.cnanational.productservice.model.DealerSeriesAttributesRequest>' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {}
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoMatchingBeanFound(DefaultListableBeanFactory.java:1493)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1104)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066)
    at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:835)

下面给出了调用bean的服务类

@Service
public class ProductServiceImpl implements ProductService {

    private final Logger log = LoggerFactory.getLogger(getClass());

    private final Validator<SeriesSurchargesRequest> seriesSurchargesRequestValidator;

    private final Validator<DealerSeriesAttributesRequest> dealerSeriesAttributesRequestValidator;

    private final ProductServiceDao productDao;

    @Value("${spring.application.name}")
    private String serviceName;

    @Autowired
    public ProductServiceImpl(
            final ProductServiceDao productDao, final Validator<SeriesSurchargesRequest> seriesSurchargesRequestValidator,
            final Validator<DealerSeriesAttributesRequest> dealerSeriesAttributesRequestValidator )
    {
        this.productDao = productDao;
        this.seriesSurchargesRequestValidator = seriesSurchargesRequestValidator;
        this.dealerSeriesAttributesRequestValidator = dealerSeriesAttributesRequestValidator;
    }

    @Override
    public SeriesSurcharges getSurcharges(SeriesSurchargesRequest stdOptions) {

    this.seriesSurchargesRequestValidator.validateAndThrowIfInvalid(
                stdOptions,
                "SeriesSurchargesRequest");

        SeriesSurcharges charges = productDao.findSurcharges(stdOptions);

        return charges;
    }

    @Override
    public List<DealerSeriesAttribute> getDealerSeriesAttributes(DealerSeriesAttributesRequest request) throws Exception {         
           this.dealerSeriesAttributesRequestValidator.validateAndThrowIfInvalid(
                request,
                "dealerSeriesAttributesRequest");
           
           List <DealerSeriesAttribute> result = new ArrayList<DealerSeriesAttribute>();
           
           for (ProductSeriesFilter psfilter : request.getProductSeriesFilters()) {
                log.debug("getDealerSeriesAttributes-1: ProductSeriesFilter: " + psfilter.toString());
                List<DealerSeriesAttribute> dsa = productDao.getDealerSeriesAttributes( request);
                result.addAll(dsa);
                log.debug("Product service Impl : The size of dsa, sizes={}", dsa.size());
           }           
           return new ArrayList<DealerSeriesAttribute>(result);         
    }
}

以下是Validator类。

public class CreateDealerSeriesAttributesRequestValidator implements Validator<DealerSeriesAttributesRequest>{

    private final SmartValidator smartValidator;

    public CreateDealerSeriesAttributesRequestValidator(final SmartValidator smartValidator)
    {
        this.smartValidator = smartValidator;
    }

    @Override
    public boolean supports(Class<?> clazz) {
        return DealerSeriesAttributesRequest.class.equals(clazz);
    }

    @Override
    public void validate(Object target, Errors errors) {}

    @Override
    public SmartValidator smartValidator() {
        return smartValidator;
    }
}

Answer 1

我猜你的包com.cnanational.productservice.model不在你的入口点（用@SpringBootApplication注释的类）的包下面

Spring需要知道在哪里扫描bean，在Spring启动时，默认情况下spring boot会扫描用@SpringBootApplication注释的类的包以及该包下的包，也可以使用@componantscan指定包你需要扫描，所以你可以像这样解决你的问题

@SpringBootApplication
@ComponentScan("com.cnanational.productservice.model")

或将您的bean实现放在一个默认扫描的包中。

此外，您需要确保您的类已注册为bean，因此如果您的Validator接口未注册为bean，您可以注释Validator或CreateDealerSeriesAttributesRequestValidator @Component或使用@Bean创建一个CreateDealerSeriesAttributesRequestValidator实例。你的配置类。

注意，因为您使用自动装配的接口，当您有多个实现时需要小心，您需要帮助Spring决定使用@Qualifier选择哪个实现

Answer 2

要么SpringBootApplication类不在根包中，要么Validator类没有注册为Spring bean。

确保您的SpringBootApplication类位于根包中，即com.cnanational，类com.cnanational.servicecommon.validation.Validator注释为@Component，将其注册为spring bean。