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javagraphql-java

Static data fetcher returns null (GraphQL/Java)


I have following simple schema/query example with programmatic schema creation in Java. Here, I am trying to create following schema:

query{
  board {
   name: string
 }
}

Code:

GraphQLObjectType queryType = GraphQLObjectType.newObject()
                .name("BoardQuery")
                .field(GraphQLFieldDefinition.newFieldDefinition()
                        .name("board")
                        .type(GraphQLObjectType.newObject().name("boardType")
                        .field(GraphQLFieldDefinition.newFieldDefinition()
                                .name("name")
                                .type(GraphQLString).build()))

                        .build())

                .build();

        GraphQLCodeRegistry graphQLCodeRegistry = GraphQLCodeRegistry.newCodeRegistry()
                .dataFetcher(FieldCoordinates.coordinates("boardType","name"),
                        new StaticDataFetcher("hello")).build();
        GraphQLSchema graphQLSchema = GraphQLSchema.newSchema()
                .query(queryType)
                .codeRegistry(graphQLCodeRegistry)
                .build();
        GraphQL graphQl = GraphQL.newGraphQL(graphQLSchema).build();
        ExecutionResult executionResult = graphQl.execute("query { board { name } }");
        System.out.println(executionResult.getData().toString());

Expected output:

{name:hello}

Actual output:

{name:null}

Am I missing something here?


Solution

  • Im new to this myself but this i'll give it a shot.

        //The dataFetcher used to fetch a board object.
        DataFetcher boardDataFetcher() {
            return environment -> {
                Object board = new Object() {
                    String name = "board Name";
                };
                return board;
            };
        }
        //Your deffinition of what a board type contains/what of the board type you want to expose
        public GraphQLObjectType boardType = newObject()
                .name("boardType")
                .field(newFieldDefinition()
                        .name("name")
                        .type(GraphQLString)
                )
                .build();
        // Define your query types 
        public GraphQLObjectType queryType = newObject()
                .name("Query")
                .field(newFieldDefinition()
                        .name("board")
                        .type(boardType)
                )
                .build();
    
        // wire the query, board and datafetcher together
        public GraphQLCodeRegistry codeRegistry = newCodeRegistry()
                .dataFetcher(
                        coordinates("Query", "board"), boardDataFetcher()
                )
                .build();
        //create the schema
        GraphQLSchema graphQLSchema = GraphQLSchema.newSchema()
                .query(queryType)
                .codeRegistry(codeRegistry)
                .build();
    

    This works with a query like

    board{name}
    

    Should give you the response:

    "board": {
          "name": "board Name"
        }