Question

我的理解是null在graphql响应中是可接受的值。因此，我必须误解了某些东西，或者我做的是根本上错误的事情，因为现在我得到的是“ java.lang.Object@7deb1b9”而不是null。

schema {
  query: Query
}

type Query {
  greeting: String
}

Graphql看起来像这样：

        final Builder vContextBuilder = new Builder()
                .of("locale", mLocale)
                .of("securityContext", mSecurityContext);

        final ExecutionInput vExecutionInput = ExecutionInput
                .newExecutionInput()
                .query(mQuery)
                .context(vContextBuilder)
                .build();

        final InputStream vSchemaInputStream = Thread
                .currentThread()
                .getContextClassLoader()
                .getResourceAsStream(SCHEMA_FILE_URI);

        final TypeDefinitionRegistry vTypeDefinitionRegistry = new SchemaParser()
                .parse(new InputStreamReader(vSchemaInputStream));

        final RuntimeWiring vRuntimeWiring = RuntimeWiring.newRuntimeWiring()
                .type("Query", typeWiring -> typeWiring
                        .dataFetcher("greeting", new GreetingFetcher())
                        )
                .build();

        final GraphQLSchema vGraphQLSchema = new SchemaGenerator()
                .makeExecutableSchema(vTypeDefinitionRegistry, vRuntimeWiring);

        final GraphQL vGraphQL = GraphQL.newGraphQL(vGraphQLSchema)
                .build();

        final ExecutionResult vExecutionResult = vGraphQL.execute(vExecutionInput);

        final Map<String, Object> toSpecificationResult = vExecutionResult.toSpecification();

和Greetingfetcher：

public class GreetingFetcher extends StaticDataFetcher {

    public GreetingFetcher() {
        super("Hello!");
        //super(null);
    }
}

查询：

query {
  greeting
}

来自super("Hello!");的回复：

{
    "data": {
        "greeting": "Hello!"
    }
}

来自super(null);的回复：

{
    "data": {
        "greeting": "java.lang.Object@7deb1b9"
    }
}

应该不是：

{
    "data": {
        "greeting": null
    }
}

有人有什么主意吗？

Answer 1

问题与进口有关。当我将其更改为import graphql.nextgen.GraphQL;时，Eclipse已添加import graphql.GraphQL;。

为什么将null的String作为java.lang.Object @。返回？

1 个答案: