GraphQL - 联合类型给出错误 no class could be found for that type name

Posted 2023-03-10

【中文标题】GraphQL - 联合类型给出错误 no class could be found for that type name

【英文标题】：GraphQL - Union Types giving the error no class could be found for that type name

【发布时间】：2020-05-04 02:05:37

【问题描述】：

在我的 GraphQL 架构文件中，我尝试添加一个联合类型，如下所示：

type CoOverrides 
    coId: String
    type: String


type SoOverrides 
    soId: String
    freeInterval: String


union CoOrSoOverrides = CoOverrides | SoOverrides

然后我将它分配给我的类型，如下所示：

type Campaign 
    id: ID!
    title: String
    overrides: [CoOrSoOverrides]

但是在启动 graphql 服务器时，我不断收到错误消息：

Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.coxautodev.graphql.tools.SchemaParser]: Factory method 'schemaParser' threw exception; 
nested exception is com.coxautodev.graphql.tools.SchemaClassScannerError: 
Object type 'CoOverrides' is a member of a known union, but no class could be found for that type name.  Please pass a class for type 'CoOverrides' in the parser's dictionary.

这到底是什么以及如何将这个类添加到解析器的字典中？

任何帮助表示赞赏。

谢谢。

【参考方案1】：

如错误消息中所示 - 将 CoOverrides 类传递给字典。

@Configuration
public class SchemaParserConfig 

    @Bean
    public SchemaParserDictionary schemaParserDictionary() 
        return new SchemaParserDictionary()
                .add(CoOverrides.class);