This version is still in development and is not considered stable yet. For the latest stable version, please use Spring GraphQL 1.3.2!spring-doc.cn

This version is still in development and is not considered stable yet. For the latest stable version, please use Spring GraphQL 1.3.2!spring-doc.cn

ExecutionGraphQlService is the main Spring abstraction to call GraphQL Java to execute requests. Underlying transports, such as the HTTP, delegate to ExecutionGraphQlService to handle requests.spring-doc.cn

The main implementation, DefaultExecutionGraphQlService, is configured with a GraphQlSource for access to the graphql.GraphQL instance to invoke.spring-doc.cn

GraphQLSource

GraphQlSource is a contract to expose the graphql.GraphQL instance to use that also includes a builder API to build that instance. The default builder is available via GraphQlSource.schemaResourceBuilder().spring-doc.cn

The Boot Starter creates an instance of this builder and further initializes it to load schema files from a configurable location, to expose properties to apply to GraphQlSource.Builder, to detect RuntimeWiringConfigurer beans, Instrumentation beans for GraphQL metrics, and DataFetcherExceptionResolver and SubscriptionExceptionResolver beans for exception resolution. For further customizations, you can also declare a GraphQlSourceBuilderCustomizer bean, for example:spring-doc.cn

@Configuration(proxyBeanMethods = false)
class GraphQlConfig {

	@Bean
	public GraphQlSourceBuilderCustomizer sourceBuilderCustomizer() {
		return (builder) ->
				builder.configureGraphQl(graphQlBuilder ->
						graphQlBuilder.executionIdProvider(new CustomExecutionIdProvider()));
	}
}

Schema Resources

GraphQlSource.Builder can be configured with one or more Resource instances to be parsed and merged together. That means schema files can be loaded from just about any location.spring-doc.cn

By default, the Boot starter looks for schema files with extensions ".graphqls" or ".gqls" under the location classpath:graphql/**, which is typically src/main/resources/graphql. You can also use a file system location, or any location supported by the Spring Resource hierarchy, including a custom implementation that loads schema files from remote locations, from storage, or from memory.spring-doc.cn

Use classpath*:graphql/**/ to find schema files across multiple classpath locations, e.g. across multiple modules.

Schema Creation

By default, GraphQlSource.Builder uses the GraphQL Java SchemaGenerator to create the graphql.schema.GraphQLSchema. This works for typical use, but if you need to use a different generator, e.g. for federation, you can register a schemaFactory callback:spring-doc.cn

GraphQlSource.Builder builder = ...

builder.schemaResources(..)
		.configureRuntimeWiring(..)
		.schemaFactory((typeDefinitionRegistry, runtimeWiring) -> {
			// create GraphQLSchema
		})

The GraphQlSource section explains how to configure that with Spring Boot.spring-doc.cn

For an example with Apollo Federation, see federation-jvm-spring-example.spring-doc.cn

RuntimeWiringConfigurer

You can use RuntimeWiringConfigurer to register:spring-doc.cn

GraphQL Java, server applications use Jackson only for serialization to and from maps of data. Client input is parsed into a map. Server output is assembled into a map based on the field selection set. This means you can’t rely on Jackson serialization/deserialization annotations. Instead, you can use custom scalar types.

The Boot Starter detects beans of type RuntimeWiringConfigurer and registers them in the GraphQlSource.Builder. That means in most cases, you’ll' have something like the following in your configuration:spring-doc.cn

@Configuration
public class GraphQlConfig {

	@Bean
	public RuntimeWiringConfigurer runtimeWiringConfigurer(BookRepository repository) {

		GraphQLScalarType scalarType = ... ;
		SchemaDirectiveWiring directiveWiring = ... ;
		DataFetcher dataFetcher = QuerydslDataFetcher.builder(repository).single();

		return wiringBuilder -> wiringBuilder
				.scalar(scalarType)
				.directiveWiring(directiveWiring)
				.type("Query", builder -> builder.dataFetcher("book", dataFetcher));
	}
}

If you need to add a WiringFactory, e.g. to make registrations that take into account schema definitions, implement the alternative configure method that accepts both the RuntimeWiring.Builder and an output List<WiringFactory>. This allows you to add any number of factories that are then invoked in sequence.spring-doc.cn

TypeResolver

GraphQlSource.Builder registers ClassNameTypeResolver as the default TypeResolver to use for GraphQL Interfaces and Unions that don’t already have such a registration through a RuntimeWiringConfigurer. The purpose of a TypeResolver in GraphQL Java is to determine the GraphQL Object type for values returned from the DataFetcher for a GraphQL Interface or Union field.spring-doc.cn

ClassNameTypeResolver tries to match the simple class name of the value to a GraphQL Object Type and if it is not successful, it also navigates its super types including base classes and interfaces, looking for a match. ClassNameTypeResolver provides an option to configure a name extracting function along with Class to GraphQL Object type name mappings that should help to cover more corner cases:spring-doc.cn

GraphQlSource.Builder builder = ...
ClassNameTypeResolver classNameTypeResolver = new ClassNameTypeResolver();
classNameTypeResolver.setClassNameExtractor((klass) -> {
	// Implement Custom ClassName Extractor here
});
builder.defaultTypeResolver(classNameTypeResolver);

The GraphQlSource section explains how to configure that with Spring Boot.spring-doc.cn

Directives

The GraphQL language supports directives that "describe alternate runtime execution and type validation behavior in a GraphQL document". Directives are similar to annotations in Java but declared on types, fields, fragments and operations in a GraphQL document.spring-doc.cn

GraphQL Java provides the SchemaDirectiveWiring contract to help applications detect and handle directives. For more details, see Schema Directives in the GraphQL Java documentation.spring-doc.cn

In Spring GraphQL you can register a SchemaDirectiveWiring through a RuntimeWiringConfigurer. The Boot Starter detects such beans, so you might have something like:spring-doc.cn

@Configuration
public class GraphQlConfig {

	 @Bean
	 public RuntimeWiringConfigurer runtimeWiringConfigurer() {
		  return builder -> builder.directiveWiring(new MySchemaDirectiveWiring());
	 }

}
For an example of directives support check out the Extended Validation for Graphql Java library.

ExecutionStrategy

An ExecutionStrategy in GraphQL Java drives the fetching of requested fields. To create an ExecutionStrategy, you need to provide a DataFetcherExceptionHandler. By default, Spring for GraphQL creates the exception handler to use as described in Exceptions and sets it on the GraphQL.Builder. GraphQL Java then uses that to create AsyncExecutionStrategy instances with the configured exception handler.spring-doc.cn

If you need to create a custom ExecutionStrategy, you can detect DataFetcherExceptionResolvers and create an exception handler in the same way, and use it to create the custom ExecutionStrategy. For example, in a Spring Boot application:spring-doc.cn

@Bean
GraphQlSourceBuilderCustomizer sourceBuilderCustomizer(
		ObjectProvider<DataFetcherExceptionResolver> resolvers) {

	DataFetcherExceptionHandler exceptionHandler =
			DataFetcherExceptionResolver.createExceptionHandler(resolvers.stream().toList());

	AsyncExecutionStrategy strategy = new CustomAsyncExecutionStrategy(exceptionHandler);

	return sourceBuilder -> sourceBuilder.configureGraphQl(builder ->
			builder.queryExecutionStrategy(strategy).mutationExecutionStrategy(strategy));
}

Schema Transformation

You can register a graphql.schema.GraphQLTypeVisitor via builder.schemaResources(..).typeVisitorsToTransformSchema(..) if you want to traverse and transform the schema after it is created, and make changes to the schema. Keep in mind that this is more expensive than Schema Traversal so generally prefer traversal to transformation unless you need to make schema changes.spring-doc.cn

Schema Traversal

You can register a graphql.schema.GraphQLTypeVisitor via builder.schemaResources(..).typeVisitors(..) if you want to traverse the schema after it is created, and possibly apply changes to the GraphQLCodeRegistry. Keep in mind, however, that such a visitor cannot change the schema. See Schema Transformation, if you need to make changes to the schema.spring-doc.cn

Schema Mapping Inspection

If a query, mutation, or subscription operation does not have a DataFetcher, it won’t return any data, and won’t do anything useful. Likewise, fields on schema types returned by an operation that are covered neither explicitly through a DataFetcher registration, nor implicitly by the default PropertyDataFetcher, which looks for a matching Java object property, will always be null.spring-doc.cn

GraphQL Java does not perform checks to ensure every schema field is covered, and that can result in gaps that might not be discovered depending on test coverage. At runtime you may get a "silent" null, or an error if the field is not nullable. As a lower level library, GraphQL Java simply does not know enough about DataFetcher implementations and their return types, and therefore can’t compare schema type structure against Java object structure.spring-doc.cn

Spring for GraphQL defines the SelfDescribingDataFetcher interface to allow a DataFetcher to expose return type information. All Spring DataFetcher implementations implement this interface. That includes those for Annotated Controllers, and those for Querydsl and Query by Example Spring Data repositories. For annotated controllers, the return type is derived from the declared return type on a @SchemaMapping method.spring-doc.cn

On startup, Spring for GraphQL can inspect schema fields, DataFetcher registrations, and the properties of Java objects returned from DataFetcher implementations to check if all schema fields are covered either by an explicitly registered DataFetcher, or a matching Java object property. The inspection also performs a reverse check looking for DataFetcher registrations against schema fields that don’t exist.spring-doc.cn

To enable inspection of schema mappings:spring-doc.cn

GraphQlSource.Builder builder = ...

builder.schemaResources(..)
		.inspectSchemaMappings(report -> {
			logger.debug(report);
		})

Below is an example report:spring-doc.cn

GraphQL schema inspection:
    Unmapped fields: {Book=[title], Author[firstName, lastName]} (1)
    Unmapped registrations: {Book.reviews=BookController#reviews[1 args]} (2)
    Skipped types: [BookOrAuthor] (3)
1 List of schema fields and their source types that are not mapped
2 List of DataFetcher registrations on fields that don’t exist
3 List of schema types that are skipped, as explained next

There are limits to what schema field inspection can do, in particular when there is insufficient Java type information. This is the case if an annotated controller method is declared to return java.lang.Object, or if the return type has an unspecified generic parameter such as List<?>, or if the DataFetcher does not implement SelfDescribingDataFetcher and the return type is not even known. In such cases, the Java object type structure remains unknown, and the schema type is listed as skipped in the resulting report. For every skipped type, a DEBUG message is logged to indicate why it was skipped.spring-doc.cn

Schema union types are always skipped because there is no way for a controller method to declare such a return type in Java, and the Java type structure is unknown.spring-doc.cn

Schema interface types are supported only as far as fields declared directly, which are compared against properties on the Java type declared by a SelfDescribingDataFetcher. Additional fields on concrete implementations are not inspected. This could be improved in a future release to also inspect schema interface implementation types and to try to find a match among subtypes of the declared Java return type.spring-doc.cn

Operation Caching

GraphQL Java must parse and validate an operation before executing it. This may impact performance significantly. To avoid the need to re-parse and validate, an application may configure a PreparsedDocumentProvider that caches and reuses Document instances. The GraphQL Java docs provide more details on query caching through a PreparsedDocumentProvider.spring-doc.cn

In Spring GraphQL you can register a PreparsedDocumentProvider through GraphQlSource.Builder#configureGraphQl: .spring-doc.cn

// Typically, accessed through Spring Boot's GraphQlSourceBuilderCustomizer
GraphQlSource.Builder builder = ...

// Create provider
PreparsedDocumentProvider provider =
        new ApolloPersistedQuerySupport(new InMemoryPersistedQueryCache(Collections.emptyMap()));

builder.schemaResources(..)
		.configureRuntimeWiring(..)
		.configureGraphQl(graphQLBuilder -> graphQLBuilder.preparsedDocumentProvider(provider))

The GraphQlSource section explains how to configure that with Spring Boot.spring-doc.cn

Use classpath*:graphql/**/ to find schema files across multiple classpath locations, e.g. across multiple modules.
GraphQL Java, server applications use Jackson only for serialization to and from maps of data. Client input is parsed into a map. Server output is assembled into a map based on the field selection set. This means you can’t rely on Jackson serialization/deserialization annotations. Instead, you can use custom scalar types.
For an example of directives support check out the Extended Validation for Graphql Java library.
1 List of schema fields and their source types that are not mapped
2 List of DataFetcher registrations on fields that don’t exist
3 List of schema types that are skipped, as explained next

Thread Model

Most GraphQL requests benefit from concurrent execution in fetching nested fields. This is why most applications today rely on GraphQL Java’s AsyncExecutionStrategy, which allows data fetchers to return CompletionStage and to execute concurrently rather than serially.spring-doc.cn

Java 21 and virtual threads add an important ability to use more threads efficiently, but it is still necessary to execute concurrently rather than serially in order for request execution to complete more quickly.spring-doc.cn

Spring for GraphQL supports:spring-doc.cn

Spring for GraphQL runs on either Spring MVC or WebFlux as the transport. Spring MVC uses async request execution, unless the resulting CompletableFuture is done immediately after the GraphQL Java engine returns, which would be the case if the request is simple enough and did not require asynchronous data fetching.spring-doc.cn

Reactive DataFetcher

The default GraphQlSource builder enables support for a DataFetcher to return Mono or Flux which adapts those to a CompletableFuture where Flux values are aggregated and turned into a List, unless the request is a GraphQL subscription request, in which case the return value remains a Reactive Streams Publisher for streaming GraphQL responses.spring-doc.cn

A reactive DataFetcher can rely on access to Reactor context propagated from the transport layer, such as from a WebFlux request handling, see WebFlux Context.spring-doc.cn

Context Propagation

Spring for GraphQL provides support to transparently propagate context from the HTTP transport, through GraphQL Java, and to DataFetcher and other components it invokes. This includes both ThreadLocal context from the Spring MVC request handling thread and Reactor Context from the WebFlux processing pipeline.spring-doc.cn

WebMvc

A DataFetcher and other components invoked by GraphQL Java may not always execute on the same thread as the Spring MVC handler, for example if an asynchronous WebGraphQlInterceptor or DataFetcher switches to a different thread.spring-doc.cn

Spring for GraphQL supports propagating ThreadLocal values from the Servlet container thread to the thread a DataFetcher and other components invoked by GraphQL Java to execute on. To do this, an application needs to implement io.micrometer.context.ThreadLocalAccessor for a ThreadLocal values of interest:spring-doc.cn

public class RequestAttributesAccessor implements ThreadLocalAccessor<RequestAttributes> {

    @Override
    public Object key() {
        return RequestAttributesAccessor.class.getName();
    }

    @Override
    public RequestAttributes getValue() {
        return RequestContextHolder.getRequestAttributes();
    }

    @Override
    public void setValue(RequestAttributes attributes) {
        RequestContextHolder.setRequestAttributes(attributes);
    }

    @Override
    public void reset() {
        RequestContextHolder.resetRequestAttributes();
    }

}

You can register a ThreadLocalAccessor manually on startup with the global ContextRegistry instance, which is accessible via io.micrometer.context.ContextRegistry#getInstance(). You can also register it automatically through the java.util.ServiceLoader mechanism.spring-doc.cn

WebFlux

A Reactive DataFetcher can rely on access to Reactor context that originates from the WebFlux request handling chain. This includes Reactor context added by WebGraphQlInterceptor components.spring-doc.cn

Exceptions

In GraphQL Java, DataFetcherExceptionHandler decides how to represent exceptions from data fetching in the "errors" section of the response. An application can register a single handler only.spring-doc.cn

Spring for GraphQL registers a DataFetcherExceptionHandler that provides default handling and enables the DataFetcherExceptionResolver contract. An application can register any number of resolvers via GraphQLSource builder and those are in order until one them resolves the Exception to a List<graphql.GraphQLError>. The Spring Boot starter detects beans of this type.spring-doc.cn

DataFetcherExceptionResolverAdapter is a convenient base class with protected methods resolveToSingleError and resolveToMultipleErrors.spring-doc.cn

The Annotated Controllers programming model enables handling data fetching exceptions with annotated exception handler methods with a flexible method signature, see @GraphQlExceptionHandler for details.spring-doc.cn

A GraphQLError can be assigned to a category based on the GraphQL Java graphql.ErrorClassification, or the Spring GraphQL ErrorType, which defines the following:spring-doc.cn

If an exception remains unresolved, by default it is categorized as an INTERNAL_ERROR with a generic message that includes the category name and the executionId from DataFetchingEnvironment. The message is intentionally opaque to avoid leaking implementation details. Applications can use a DataFetcherExceptionResolver to customize error details.spring-doc.cn

Unresolved exception are logged at ERROR level along with the executionId to correlate to the error sent to the client. Resolved exceptions are logged at DEBUG level.spring-doc.cn

Request Exceptions

The GraphQL Java engine may run into validation or other errors when parsing the request and that in turn prevent request execution. In such cases, the response contains a "data" key with null and one or more request-level "errors" that are global, i.e. not having a field path.spring-doc.cn

DataFetcherExceptionResolver cannot handle such global errors because they are raised before execution begins and before any DataFetcher is invoked. An application can use transport level interceptors to inspect and transform errors in the ExecutionResult. See examples under WebGraphQlInterceptor.spring-doc.cn

Subscription Exceptions

The Publisher for a subscription request may complete with an error signal in which case the underlying transport (e.g. WebSocket) sends a final "error" type message with a list of GraphQL errors.spring-doc.cn

DataFetcherExceptionResolver cannot resolve errors from a subscription Publisher, since the data DataFetcher only creates the Publisher initially. After that, the transport subscribes to the Publisher that may then complete with an error.spring-doc.cn

An application can register a SubscriptionExceptionResolver in order to resolve exceptions from a subscription Publisher in order to resolve those to GraphQL errors to send to the client.spring-doc.cn

Pagination

The GraphQL Cursor Connection specification defines a way to navigate large result sets by returning a subset of items at a time where each item is paired with a cursor that clients can use to request more items before or after the referenced item.spring-doc.cn

The specification calls the pattern "Connections". A schema type with a name that ends on Connection is a Connection Type that represents a paginated result set. All ~Connection types contain an "edges" field where ~Edge type pairs the actual item with a cursor, as well as a "pageInfo" field with boolean flags to indicate if there are more items forward and backward.spring-doc.cn

Connection Types

Connection type definitions must be created for every type that needs pagination, adding boilerplate and noise to the schema. Spring for GraphQL provides ConnectionTypeDefinitionConfigurer to add these types on startup, if not already present in the parsed schema files. That means in the schema you only need this:spring-doc.cn

Query {
	books(first:Int, after:String, last:Int, before:String): BookConnection
}

type Book {
	id: ID!
	title: String!
}

Note the spec-defined forward pagination arguments first and after that clients can use to request the first N items after the given cursor, while last and before are backward pagination arguments to request the last N items before the given cursor.spring-doc.cn

Next, configure ConnectionTypeDefinitionConfigurer as follows:spring-doc.cn

GraphQlSource.schemaResourceBuilder()
		.schemaResources(..)
		.typeDefinitionConfigurer(new ConnectionTypeDefinitionConfigurer)

and the following type definitions will be transparently added to the schema:spring-doc.cn

type BookConnection {
	edges: [BookEdge]!
	pageInfo: PageInfo!
}

type BookEdge {
	node: Book!
	cursor: String!
}

type PageInfo {
	hasPreviousPage: Boolean!
	hasNextPage: Boolean!
	startCursor: String
	endCursor: String
}

The Boot Starter registers ConnectionTypeDefinitionConfigurer by default.spring-doc.cn

ConnectionAdapter

Once Connection Types are available in the schema, you also need equivalent Java types. GraphQL Java provides those, including generic Connection and Edge, as well as a PageInfo.spring-doc.cn

One option is to populate a Connection and return it from your controller method or DataFetcher. However, this requires boilerplate code to create the Connection, creating cursors, wrapping each item as an Edge, and creating the PageInfo. Moreover, you may already have an underlying pagination mechanism such as when using Spring Data repositories.spring-doc.cn

Spring for GraphQL defines the ConnectionAdapter contract to adapt a container of items to Connection. Adapters are applied through a DataFetcher decorator that is in turn installed through a ConnectionFieldTypeVisitor. You can configure it as follows:spring-doc.cn

ConnectionAdapter adapter = ... ;
GraphQLTypeVisitor visitor = ConnectionFieldTypeVisitor.create(List.of(adapter)) (1)

GraphQlSource.schemaResourceBuilder()
		.schemaResources(..)
		.typeDefinitionConfigurer(..)
		.typeVisitors(List.of(visitor)) (2)
1 Create type visitor with one or more ConnectionAdapters.
2 Resister the type visitor.

There are built-in ConnectionAdapters for Spring Data’s Window and Slice. You can also create your own custom adapter. ConnectionAdapter implementations rely on a CursorStrategy to create cursors for returned items. The same strategy is also used to support the Subrange controller method argument that contains pagination input.spring-doc.cn

CursorStrategy

CursorStrategy is a contract to encode and decode a String cursor that refers to the position of an item within a large result set. The cursor can be based on an index or on a keyset.spring-doc.cn

A ConnectionAdapter uses this to encode cursors for returned items. Annotated Controllers methods, Querydsl repositories, and Query by Example repositories use it to decode cursors from pagination requests, and create a Subrange.spring-doc.cn

CursorEncoder is a related contract that further encodes and decodes String cursors to make them opaque to clients. EncodingCursorStrategy combines CursorStrategy with a CursorEncoder. You can use Base64CursorEncoder, NoOpEncoder or create your own.spring-doc.cn

There is a built-in CursorStrategy for the Spring Data ScrollPosition. The Boot Starter registers a CursorStrategy<ScrollPosition> with Base64Encoder when Spring Data is present.spring-doc.cn

Sort

There is no standard way to provide sort information in a GraphQL request. However, pagination depends on a stable sort order. You can use a default order, or otherwise expose input types and extract sort details from GraphQL arguments.spring-doc.cn

There is built-in support for Spring Data’s Sort as a controller method argument. For this to work, you need to have a SortStrategy bean.spring-doc.cn

1 Create type visitor with one or more ConnectionAdapters.
2 Resister the type visitor.

Batch Loading

Given a Book and its Author, we can create one DataFetcher for a book and another for its author. This allows selecting books with or without authors, but it means books and authors aren’t loaded together, which is especially inefficient when querying multiple books as the author for each book is loaded individually. This is known as the N+1 select problem.spring-doc.cn

DataLoader

GraphQL Java provides a DataLoader mechanism for batch loading of related entities. You can find the full details in the GraphQL Java docs. Below is a summary of how it works:spring-doc.cn

  1. Register DataLoader's in the DataLoaderRegistry that can load entities, given unique keys.spring-doc.cn

  2. DataFetcher's can access DataLoader's and use them to load entities by id.spring-doc.cn

  3. A DataLoader defers loading by returning a future so it can be done in a batch.spring-doc.cn

  4. DataLoader's maintain a per request cache of loaded entities that can further improve efficiency.spring-doc.cn

BatchLoaderRegistry

The complete batching loading mechanism in GraphQL Java requires implementing one of several BatchLoader interface, then wrapping and registering those as DataLoaders with a name in the DataLoaderRegistry.spring-doc.cn

The API in Spring GraphQL is slightly different. For registration, there is only one, central BatchLoaderRegistry exposing factory methods and a builder to create and register any number of batch loading functions:spring-doc.cn

@Configuration
public class MyConfig {

	public MyConfig(BatchLoaderRegistry registry) {

		registry.forTypePair(Long.class, Author.class).registerMappedBatchLoader((authorIds, env) -> {
				// return Mono<Map<Long, Author>
		});

		// more registrations ...
	}

}

The Boot Starter declares a BatchLoaderRegistry bean that you can inject into your configuration, as shown above, or into any component such as a controller in order register batch loading functions. In turn the BatchLoaderRegistry is injected into DefaultExecutionGraphQlService where it ensures DataLoader registrations per request.spring-doc.cn

By default, the DataLoader name is based on the class name of the target entity. This allows an @SchemaMapping method to declare a DataLoader argument with a generic type, and without the need for specifying a name. The name, however, can be customized through the BatchLoaderRegistry builder, if necessary, along with other DataLoaderOptions.spring-doc.cn

To configure default DataLoaderOptions globally, to use as a starting point for any registration, you can override Boot’s BatchLoaderRegistry bean and use the constructor for DefaultBatchLoaderRegistry that accepts Supplier<DataLoaderOptions>.spring-doc.cn

For many cases, when loading related entities, you can use @BatchMapping controller methods, which are a shortcut for and replace the need to use BatchLoaderRegistry and DataLoader directly.spring-doc.cn

BatchLoaderRegistry provides other important benefits too. It supports access to the same GraphQLContext from batch loading functions and from @BatchMapping methods, as well as ensures Context Propagation to them. This is why applications are expected to use it. It is possible to perform your own DataLoader registrations directly but such registrations would forgo the above benefits.spring-doc.cn

Testing Batch Loading

Start by having BatchLoaderRegistry perform registrations on a DataLoaderRegistry:spring-doc.cn

BatchLoaderRegistry batchLoaderRegistry = new DefaultBatchLoaderRegistry();
// perform registrations...

DataLoaderRegistry dataLoaderRegistry = DataLoaderRegistry.newRegistry().build();
batchLoaderRegistry.registerDataLoaders(dataLoaderRegistry, graphQLContext);

Now you can access and test individual DataLoader's as follows:spring-doc.cn

DataLoader<Long, Book> loader = dataLoaderRegistry.getDataLoader(Book.class.getName());
loader.load(1L);
loader.loadMany(Arrays.asList(2L, 3L));
List<Book> books = loader.dispatchAndJoin(); // actual loading

assertThat(books).hasSize(3);
assertThat(books.get(0).getName()).isEqualTo("...");
// ...