用于具有多个提供程序的服务的Spring Boot设计（小型服务）

Question

我正在创建一个Spring Boot应用程序，我在设计服务时需要帮助。 我将以自行车服务为例。 让我们考虑以下端点：

/api/bike/v1/info
/api/bike/v1/find

端点将调用Bike服务，该服务可能会调用不同的提供程序，例如BikeProvider1，BikeProvider2等。提供程序将在应用程序的属性中指定，这允许更改提供程序而无需重新启动应用程序。

结构实例

+ bike
     + Client
         - BikeRequest.java
         - BikeResponse.java
     + domain
         - Providers.java //providers enums
         - ServiceType.java // service type enums
        + Exceptions
     + Controller
        - BikeController.java
     + Service
        + Providers
            - BikeProviderService.java //interface
            - BikeProbider1ProviderService.java // implements interface
            - BikeProbider2ProviderService.java // implements interface
        - BikeService.java //interface
        - BikeServiceImpl.java

Properties.file
  bike.provider.primary: BikeProvider1
  bike.provider.fallback: BikeProvider2

我还认为，将来我希望有2个提供商作为后备，以防第一个提供商没有响应。 但是现在，我将仅使用主数据库。

我当前的设计是这样，我有用于服务类型和提供程序的枚举类。 在BikeServiceImpl.java中，我动态找到所需的提供程序并进行调用。

*******************ENUM CLASSES **************************
public enum Provider {
    BIKEPROVIDER1 ("BikeProvider1"),
    BIKEPROVIDER2  ("BikeProbider2"),

    private String name;

    Provider(final String name) {
        this.name = name;
    }
}

public enum ServiceType {
    BIKEINFORMATION ("BikeInformation"),
    FINDBIKE ("FindBike");

    private String type;

    ServiceType(final String name) {
        this.type = name;
    }
}


*****************BikeProviderService interface**************************

// this is the interface that all providers will implement
public interface BikeProviderService {
    Optional<Bike> getBikeInformation(BikeRequest bike);
    Optional<Bike> findBike(BikeRequest bike);
}

*****************BikeServiceImpl**************************

public class BikeServiceImpl implements BikeService {
    // I autowired providers
    @Autowired
    private BikeProvider1 bikeProvider1;
    @Autowired
    private BikeProvider2 bikeProvider2;

    //Get the provider from the properties
    @Value("${bike.provider.primary:}")
    private String primaryProvider;

// This is the call from controller endpoint /api/bike/v1/info 
    @Override
    public Bike findBikeInformation(BikeRequest bike, ServiceType serviceType) throws ServiceProviderException, BikeNotFoundException {
        return executeBikeInformationWithProvider(primaryProvider, bike, serviceType);
    }

    private Bike executeBikeInformationWithProvider(String provider, BikeRequest bike, ServiceType serviceType) throws ServiceProviderException, BikeNotFoundException {
        // find the providers based on the property value
        Optional<BikeProviderService> bikeProviderService = providerImplementation(provider);

        Optional<Bike> bikeResponse;
        if (BikeProviderService.isPresent()) {
            try {
                bikeResponse = bikeProviderService.get().getBikeInformation(bike);
                if (bikeResponse.isPresent()) {
                    LogCacheService.logRequest(bikeResponse, provider, serviceType.getType());
                    return bikeResponse.get();
                }
            } catch (Exception ex) {
                throw new ServiceProviderException("message");
            }
        }

        throw new BikeNotFoundException("Bike Not found");
    }

// This is the call from controller endpoint /api/bike/v1/find 
    @Override
    public Bike findBike(BikeRequest bike, ServiceType serviceType) throws ServiceProviderException, BikeNotFoundException {
        return executeFindBikeWithProvider(primaryProvider, bike, serviceType) ;
    }

    private Bike executeFindBikeWithProvider(String provider, BikeRequest bike, ServiceType serviceType) throws ServiceProviderException, BikeNotFoundException {
       // find the providers based on the property value
        Optional<BikeProviderService> bikeProviderService = providerImplementation(provider);

        Optional<Bike> bikeResponse;
        if (bikeProviderService.isPresent()) {
            try {
                bikeResponse = bikeProviderService.get().findBike(bike);
                if (bikeResponse.isPresent()) {
                    LogCacheService.logRequest(bike, provider, serviceType.getType());
                    return bikeResponse.get();
                }
            } catch (Exception ex) {
                throw new ServiceProviderException("message");
            }
        }

        throw new BikeNotFoundException("Bike Not found");
    }

    private Optional<BikeProviderService> providerImplementation(String bikeProvider) {
        Provider provider = null;

        try {
            provider = Provider.valueOf(bikeProvider.toUpperCase());
        } catch (IllegalArgumentException | NullPointerException ex) {
            log.error("Bike:: invalid Provider {}" , bikeProvider);
        }

        if (provider != null) {
            switch (provider) {
                case BIKEPROVIDER1:
                    return Optional.ofNullable(bikeProvider1);
                case BIKEPROVIDER2:
                    return Optional.ofNullable(bikeProvider2);
                default:
                    return Optional.empty();
            }
        }
        return Optional.empty();
    }

我非常努力地不重复代码，但是我担心我会使此代码过于复杂并且难以维护。 立即添加新的提供程序：

1.- add to the enum provider class
2.- add to the switch statement
3.- add the service and @AutoWire the class

我尝试了工厂模式，但是我不想每次都创建提供者的新实例。 并且接近于我拥有的providerImplementation方法。

另外，我创建了执行/辅助方法，因为正如我前面提到的，我愿做一回退或与恢复方法fallback.Provider的未来。 示例如果findBike失败，我可以调用带有后备功能的executeFindBikeWithProvider。 executeFindBikeWithProvider(**fallbackProvider**, bike, serviceType)

谢谢，让我知道您是否需要更多详细信息。

Answer 1

这不是Spring @Profile的好用例吗？

https://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-profiles.html

https://www.baeldung.com/spring-profiles

您可以使用其他配置文件来更改运行时配置，而不是使用属性文件中的提供程序列表。 这将有效地使您根据个人资料设置忽略或启用您的提供程序。

这样，添加新的提供程序仅需要您实现新的提供程序并将其与配置文件相关联。