Graphql使用输入类型来搜索数据

问题描述

我在使用 graphql 中的输入数据进行搜索时遇到问题:

I have problem searching with using Input data in graphql:

@RestController
@RequestMapping("/api/dictionary/")
@RequiredArgsConstructor(onConstructor = @__(@Autowired))
public class DictionaryController {
    @Value("classpath:items.graphqls")
    private Resource schemaResource;
    private GraphQL graphQL;
    private final DictionaryService dictionaryService;

    @PostConstruct
    public void loadSchema() throws IOException {
        File schemaFile = schemaResource.getFile();
        TypeDefinitionRegistry registry = new SchemaParser().parse(schemaFile);
        RuntimeWiring wiring = buildWiring();
        GraphQLSchema schema = new SchemaGenerator().makeExecutableSchema(registry, wiring);
        graphQL = GraphQL.newGraphQL(schema).build();
    }

private RuntimeWiring buildWiring() {

            DataFetcher<String> fetcher9 = dataFetchingEnvironment ->
            getByInput((dataFetchingEnvironment.getArgument("example")));

        return RuntimeWiring.newRuntimeWiring()
                .type("Query", typeWriting ->
                   typeWriting
                    .dataFetcher("getByInput", fetcher9)
                    )
                .build();
    }


public String getByInput(Character character) {
    return "testCharacter";
}
  }

items.graphqls 文件内容:

type Query {
   getByInput(example: Character): String
}

input Character {
    name: String
}

在请求这样的资源时:

query {
    getByInput (example: {name: "aa"} )
}

字符DTO:

@NoArgsConstructor
@AllArgsConstructor
@Data
public class Character {
    protected String name;
}

我有一个错误:

"Exception while fetching data (/getByInput) : java.util.LinkedHashMap cannot be cast to pl.graphql.Character",

查询应如何显示?

修改

如果我更改为:

public String getByInput(Object character)

代码运行正常-但我想转换为工作.

The codes runs fine - but i want convert to work.

推荐答案

对于类型为 input 类型的输入参数， graphql-java 会将其转换为地图.

For the input argument which the type is the input type , graphql-java will convert it to a Map.

在您的情况下，查询为 getByInput(示例:{name:"aa"})，其中 example 参数是 input 类型.所以，

In your case the query is getByInput (example: {name: "aa"} ) which the example argument is the input type . So ,

dataFetchingEnvironment.get("example");

将返回一个结构为(key ="name"，value ="aa")的Map.然后，您尝试将地图转换为 Character ，这肯定会给您一个错误，因为它们完全是不同种类.

will return a Map with the structure (key="name" , value="aa") .Then you try to cast the map to Character which definitely gives you an error since they are totally different types.

要将Map转换为 Character ， graphql-java 不会帮助您进行此类转换.您必须自己实施转换代码，或使用其他库，例如 Jackson和Gson，推土机或任何您喜欢的库，用于将地图转换为您的域对象(即角色).

To convert a Map to a Character , graphql-java will not help you for such conversion. You have to implement the conversion codes by yourselves or use other libraries such as Jackson , Gson , Dozer or whatever libraries you like for converting a map to your domain object (i.e. Character).

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