Why is a String that is null returned as java.lang.Object@.?

Question

My understanding is that null is an acceptable value in a graphql response. So I must either have misunderstood something or i am doing something fundamentally wrong because now i am getting "java.lang.Object@7deb1b9" instead of null.

schema {
  query: Query
}

type Query {
  greeting: String
}

Graphql looking like this:

        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();

And the Greetingfetcher:

public class GreetingFetcher extends StaticDataFetcher {

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

Query:

query {
  greeting
}

Response from super("Hello!");:

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

Response from super(null);:

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

Should the response not be:

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

Anyone got any ideas?

Answer 1

Problem was with the imports. Eclipse had added import graphql.nextgen.GraphQL; when i changed that to import graphql.GraphQL; everything worked fine.