Spring GraphQL SPQR集成Apollo Federation-JVM遇问题求助

问题背景 #

基于Spring Boot的GraphQL SPQR服务作为子图，需通过Apollo Server整合为超图。为让子图Schema兼容联邦规范，使用Apollo的federation-jvm项目，借助其SchemaTransformer添加联邦通用类型（如_Any标量、_Entity联合类型、联邦指令等）。

问题1：添加FederationSchemaFactory Bean后启动报错 #

按照项目示例添加以下两个Bean后，启动时抛出No GraphQL schema definition was configured错误：

@Bean
public GraphQlSourceBuilderCustomizer customizer(FederationSchemaFactory factory) {
    return builder -> builder.schemaFactory(factory::createGraphQLSchema);
}

@Bean
FederationSchemaFactory federationSchemaFactory() {
    return new FederationSchemaFactory();
}

完整堆栈追踪：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'routerFunctionMapping' defined in class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]: Error creating bean with name 'graphQlRouterFunction' defined in class path resource [org/springframework/boot/autoconfigure/graphql/servlet/GraphQlWebMvcAutoConfiguration.class]: Unsatisfied dependency expressed through method 'graphQlRouterFunction' parameter 0: Error creating bean with name 'graphQlHttpHandler' defined in class path resource [org/springframework/boot/autoconfigure/graphql/servlet/GraphQlWebMvcAutoConfiguration.class]: Unsatisfied dependency expressed through method 'graphQlHttpHandler' parameter 0: Error creating bean with name 'webGraphQlHandler' defined in class path resource [org/springframework/boot/autoconfigure/graphql/servlet/GraphQlWebMvcAutoConfiguration.class]: Unsatisfied dependency expressed through method 'webGraphQlHandler' parameter 0: Error creating bean with name 'executionGraphQlService' defined in class path resource [org/springframework/boot/autoconfigure/graphql/GraphQlAutoConfiguration.class]: Unsatisfied dependency expressed through method 'executionGraphQlService' parameter 0: Error creating bean with name 'graphQlSource' defined in class path resource [org/springframework/boot/autoconfigure/graphql/GraphQlAutoConfiguration.class]: Failed to instantiate [org.springframework.graphql.execution.GraphQlSource]: Factory method 'graphQlSource' threw exception with message: No GraphQL schema definition was configured.

问题2：自定义GraphQLSchema Bean后GUI不显示联邦指令 #

尝试自定义GraphQLSchema Bean，代码如下：

@Bean
public GraphQLSchema federatedSchema() {
    GraphQLSchema schema = new GraphQLSchemaGenerator()
            .withBasePackages("com.madhi.graphql_demo2.service", "com.madhi.graphql_demo2")
            .withOperationsFromSingletons(payrollService, employeeService)
            .generate();
    schema = Federation.transform(schema).build();
    String printedSchema = new SchemaPrinter(
            // Tweak the options accordingly
            SchemaPrinter.Options.defaultOptions().
                    includeDirectives(true)
    ).print(schema);
    System.out.println(printedSchema);
    return schema;
}

打印的Schema显示已添加federation-jvm的_service字段，但GraphQL GUI（如GraphiQL）中未显示新增的联邦指令，怀疑该修改对GUI暴露的最终Schema无效。

解决方案 #

修复No GraphQL schema definition was configured错误 #

报错核心原因是FederationSchemaFactory无法自动获取SPQR生成的原始Schema，不能直接替换schemaFactory，需在SPQR生成原始Schema后再执行联邦转换：

@Bean
public GraphQlSourceBuilderCustomizer federationCustomizer() {
    return builder -> builder.configureSchema(schema -> {
        // 先触发SPQR生成原始Schema，再执行联邦转换
        return Federation.transform(schema).build();
    });
}

同时确保SPQR的Schema生成逻辑正常：检查项目中@GraphQLApi、@GraphQLQuery等注解类被正确扫描，SPQR依赖配置完整。

让GUI显示联邦指令 #

GraphQL GUI默认不会展示所有指令，需做以下配置：

1. 确认联邦转换后的Schema包含@key、@extends等指令，可通过打印的SDL验证。
2. 配置Spring GraphQL的SchemaPrinter选项，确保暴露的Schema包含指令：

@Bean
public GraphQlSource graphQlSource(GraphQlSourceBuilder builder) {
    return builder.configureSchema(schema -> Federation.transform(schema).build())
            .schemaPrinterOptions(options -> options.includeDirectives(true))
            .build();
}

3. 重启服务或清空GUI工具缓存，部分工具会缓存旧Schema导致不更新。

完整集成步骤 #

1. 确认依赖：引入com.apollographql.federation:federation-jvm和SPQR的Spring Boot Starter（如io.leangen.graphql:spqr-spring-boot-starter）。
2. 配置SPQR：确保@GraphQLApi标注的服务类被Spring扫描到，能生成原始Schema。
3. 添加联邦转换的GraphQlSourceBuilderCustomizer Bean，实现Schema的联邦增强。
4. 配置SchemaPrinter选项，确保指令被包含在对外暴露的Schema中。

验证方式 #

• 启动服务后，访问GraphQL GUI，查看Schema文档是否包含_Entity、_Any类型及@key等联邦指令。
• 执行查询{ _service { sdl } }，返回的SDL应包含完整的联邦Schema定义。

内容的提问来源于stack exchange，提问作者Venkatesh Madhipatla