如何使用Retrofit解决多个API端点？

Question

在我的Android项目中,我使用以下Retrofit ApiModule作为一个 API端点.请注意,我使用Dagger注入依赖项.

@Module(
        complete = false,
        library = true
)
public final class ApiModule {

    public static final String PRODUCTS_BASE_URL = "https://products.com";

    @Provides
    @Singleton
    Endpoint provideEndpoint() {
        return Endpoints.newFixedEndpoint(PRODUCTS_BASE_URL);
    }

    @Provides
    @Singleton
    ObjectMapper provideObjectMapper() {
        ObjectMapper objectMapper = new ObjectMapper();
        objectMapper.setPropertyNamingStrategy(
            PropertyNamingStrategy.CAMEL_CASE_TO_LOWER_CASE_WITH_UNDERSCORES);
        return objectMapper;
    }

    @Provides
    @Singleton
    RestAdapter provideRestAdapter(
        Endpoint endpoint, ObjectMapper objectMapper) {
        return new RestAdapter.Builder()
                .setLogLevel(RestAdapter.LogLevel.NONE)
                .setEndpoint(endpoint)
                .setConverter(new JacksonConverter(objectMapper))
                .build();
    }

    @Provides
    @Singleton
    ProductsService provideProductsService(RestAdapter restAdapter) {
        return restAdapter.create(ProductsService.class);
    }

}

现在,还有另一个"http://subsidiaries.com"我希望与之通信的API(例如).是否有可能ApiModule在重用ObjectMapper和RestAdapter？时扩展给定的？或者我不应该延长它？我已经尝试复制模块了.但这涉及到我必须复制Endpoint,ObjectMapper并且...... RestAdapter有一个私有的构造函数 - 所以我不能.

Answer 1

我想你可以使用Named注释:

@Module(
        complete = false,
        library = true
)
public final class ApiModule {

    public static final String PRODUCTS_BASE_URL = "https://products.com";
    public static final String SUBSIDIARIES_BASE_URL = "https://subsidiaries.com";

    public static final String PRODUCTS = "products";
    public static final String SUBSIDIARIES = "subsidiaries";

    @Provides
    @Singleton
    @Named(PRODUCTS)
    Endpoint provideProductsEndpoint() {
        return Endpoints.newFixedEndpoint(PRODUCTS_BASE_URL);
    }

    @Provides
    @Singleton
    @Named(SUBSIDIARIES)
    Endpoint provideSubsidiariesEndpoint() {
        return Endpoints.newFixedEndpoint(SUBSIDIARIES_BASE_URL);
    }

    @Provides
    @Singleton
    ObjectMapper provideObjectMapper() {
        ObjectMapper objectMapper = new ObjectMapper();
        objectMapper.setPropertyNamingStrategy(
            PropertyNamingStrategy.CAMEL_CASE_TO_LOWER_CASE_WITH_UNDERSCORES);
        return objectMapper;
    }

    @Provides
    @Singleton
    @Named(PRODUCTS)
    RestAdapter provideProductsRestAdapter(@Named(PRODUCTS) Endpoint endpoint, ObjectMapper objectMapper) {
        return newRestAdapterBuilder(objectMapper)
                .setEndpoint(endpoint)
                .build();
    }

    @Provides
    @Singleton
    @Named(SUBSIDIARIES)
    RestAdapter provideSubsidiariesRestAdapter(@Named(SUBSIDIARIES) Endpoint endpoint, ObjectMapper objectMapper) {
        return newRestAdapterBuilder(objectMapper)
                .setEndpoint(endpoint)
                .build();
    }

    @Provides
    @Singleton
    @Named(PRODUCTS)
    ProductsService provideProductsService(@Named(PRODUCTS) RestAdapter restAdapter) {
        return restAdapter.create(ProductsService.class);
    }

    @Provides
    @Singleton
    @Named(SUBSIDIARIES)
    ProductsService provideSubsidiariesService(@Named(SUBSIDIARIES) RestAdapter restAdapter) {
        return restAdapter.create(ProductsService.class);
    }

    private RestAdapter.Builder newRestAdapterBuilder(ObjectMapper objectMapper) {
        return new RestAdapter.Builder()
                       .setLogLevel(RestAdapter.LogLevel.NONE)
                       .setConverter(new JacksonConverter(objectMapper));
    }
}

现在到处都在那里你注入ProductsService你需要任何注释与依赖@Named(PRODUCTS)或@Named(SUBSIDIARIES)取决于该变体需要.当然,除了@Named注释之外,您还可以创建自己的自定义注释并使用它们.见这里下的"预选赛".

要稍微展平模块,可以将RestAdapter的创建移动到provide*Service()方法中并删除provide*RestAdapter()方法.当然,除非你需要RestAdapters作为模块之外的依赖项.