graphql.execution.instrumentation.dataloader.DataLoaderDispatcherInstrumentation Java Examples

@PostConstruct
public void init() throws IOException {
    URL url = Resources.getResource("starWarsSchemaAnnotated.graphqls");
    String sdl = Resources.toString(url, Charsets.UTF_8);
    GraphQLSchema graphQLSchema = buildSchema(sdl);

    //
    // This example uses the DataLoader technique to ensure that the most efficient
    // loading of data (in this case StarWars characters) happens.  We pass that to data
    // fetchers via the graphql context object.
    //
    DataLoaderDispatcherInstrumentation dlInstrumentation =
            new DataLoaderDispatcherInstrumentation(dataLoaderRegistry, newOptions().includeStatistics(true));

    Instrumentation instrumentation = new ChainedInstrumentation(
            asList(new TracingInstrumentation(), dlInstrumentation)
    );


    this.graphQL = GraphQL.newGraphQL(graphQLSchema).instrumentation(instrumentation).build();
}
 

@Override
protected GraphQL graphQL() {
  String schema = vertx.fileSystem().readFileBlocking("links.graphqls").toString();

  SchemaParser schemaParser = new SchemaParser();
  TypeDefinitionRegistry typeDefinitionRegistry = schemaParser.parse(schema);

  RuntimeWiring runtimeWiring = newRuntimeWiring()
    .type("Query", builder -> builder.dataFetcher("allLinks", this::getAllLinks))
    .type("Link", builder -> builder.dataFetcher("postedBy", this::getLinkPostedBy))
    .build();

  SchemaGenerator schemaGenerator = new SchemaGenerator();
  GraphQLSchema graphQLSchema = schemaGenerator.makeExecutableSchema(typeDefinitionRegistry, runtimeWiring);
  DataLoaderDispatcherInstrumentation dispatcherInstrumentation = new DataLoaderDispatcherInstrumentation();

  return GraphQL.newGraphQL(graphQLSchema)
    .instrumentation(dispatcherInstrumentation)
    .build();
}
 

@Override
protected GraphQL graphQL() {
  String schema = vertx.fileSystem().readFileBlocking("links.graphqls").toString();

  SchemaParser schemaParser = new SchemaParser();
  TypeDefinitionRegistry typeDefinitionRegistry = schemaParser.parse(schema);

  RuntimeWiring runtimeWiring = newRuntimeWiring()
    .type("Query", builder -> builder.dataFetcher("allLinks", this::getAllLinks))
    .type("Link", builder -> builder.dataFetcher("postedBy", this::getLinkPostedBy))
    .build();

  SchemaGenerator schemaGenerator = new SchemaGenerator();
  GraphQLSchema graphQLSchema = schemaGenerator.makeExecutableSchema(typeDefinitionRegistry, runtimeWiring);
  DataLoaderDispatcherInstrumentation dispatcherInstrumentation = new DataLoaderDispatcherInstrumentation();

  return GraphQL.newGraphQL(graphQLSchema)
    .instrumentation(dispatcherInstrumentation)
    .build();
}
 

private void handleStarWars(HttpServletRequest httpRequest, HttpServletResponse httpResponse) throws IOException {
    //
    // this builds out the parameters we need like the graphql query from the http request
    QueryParameters parameters = QueryParameters.from(httpRequest);
    if (parameters.getQuery() == null) {
        //
        // how to handle nonsensical requests is up to your application
        httpResponse.setStatus(400);
        return;
    }

    ExecutionInput.Builder executionInput = newExecutionInput()
            .query(parameters.getQuery())
            .operationName(parameters.getOperationName())
            .variables(parameters.getVariables());

    //
    // the context object is something that means something to down stream code.  It is instructions
    // from yourself to your other code such as DataFetchers.  The engine passes this on unchanged and
    // makes it available to inner code
    //
    // the graphql guidance says  :
    //
    //  - GraphQL should be placed after all authentication middleware, so that you
    //  - have access to the same session and user information you would in your
    //  - HTTP endpoint handlers.
    //
    StarWarsWiring.Context context = new StarWarsWiring.Context();
    executionInput.context(context);

    //
    // you need a schema in order to execute queries
    GraphQLSchema schema = buildStarWarsSchema();

    //
    // This example uses the DataLoader technique to ensure that the most efficient
    // loading of data (in this case StarWars characters) happens.  We pass that to data
    // fetchers via the graphql context object.
    //
    DataLoaderRegistry dataLoaderRegistry = context.getDataLoaderRegistry();


    DataLoaderDispatcherInstrumentation dlInstrumentation =
            new DataLoaderDispatcherInstrumentation(dataLoaderRegistry, newOptions().includeStatistics(true));

    Instrumentation instrumentation = new ChainedInstrumentation(
            asList(new TracingInstrumentation(), dlInstrumentation)
    );

    // finally you build a runtime graphql object and execute the query
    GraphQL graphQL = GraphQL
            .newGraphQL(schema)
            // instrumentation is pluggable
            .instrumentation(instrumentation)
            .build();
    ExecutionResult executionResult = graphQL.execute(executionInput.build());

    returnAsJson(httpResponse, executionResult);
}