Standalone Setup

If your application is not using Spring Boot, you are responsible for setting up the relevant Spring for GraphQL components. Assuming that your application is already configured for Spring MVC controllers, the minimum setup will require several beans.

import java.util.List;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.ClassPathResource;
import org.springframework.graphql.ExecutionGraphQlService;
import org.springframework.graphql.data.method.annotation.support.AnnotatedControllerConfigurer;
import org.springframework.graphql.execution.ConnectionTypeDefinitionConfigurer;
import org.springframework.graphql.execution.DefaultBatchLoaderRegistry;
import org.springframework.graphql.execution.DefaultExecutionGraphQlService;
import org.springframework.graphql.execution.GraphQlSource;
import org.springframework.graphql.server.WebGraphQlHandler;
import org.springframework.graphql.server.webmvc.GraphQlHttpHandler;
import org.springframework.graphql.server.webmvc.GraphQlRequestPredicates;
import org.springframework.graphql.server.webmvc.GraphiQlHandler;
import org.springframework.web.servlet.function.RequestPredicate;
import org.springframework.web.servlet.function.RouterFunction;
import org.springframework.web.servlet.function.RouterFunctions;
import org.springframework.web.servlet.function.ServerResponse;

@Configuration(proxyBeanMethods = false)
public class GraphQlConfiguration {

	@Bean (1)
	public AnnotatedControllerConfigurer controllerConfigurer() {
		return new AnnotatedControllerConfigurer();
	}

	@Bean (2)
	public ExecutionGraphQlService executionGraphQlService(AnnotatedControllerConfigurer controllerConfigurer) {
		GraphQlSource graphQlSource = GraphQlSource.schemaResourceBuilder() (3)
				.schemaResources(new ClassPathResource("graphql/schema.graphqls"))
				.configureTypeDefinitions(new ConnectionTypeDefinitionConfigurer())
				.configureRuntimeWiring(controllerConfigurer)
				.exceptionResolvers(List.of(controllerConfigurer.getExceptionResolver()))
				.build();
		DefaultBatchLoaderRegistry batchLoaderRegistry = new DefaultBatchLoaderRegistry();
		DefaultExecutionGraphQlService service = new DefaultExecutionGraphQlService(graphQlSource);
		service.addDataLoaderRegistrar(batchLoaderRegistry);
		return service;
	}


	@Bean (4)
	public RouterFunction<ServerResponse> graphQlRouterFunction(ExecutionGraphQlService graphQlService) {
		WebGraphQlHandler webGraphQlHandler = WebGraphQlHandler.builder(graphQlService).build();
		GraphQlHttpHandler graphQlHttpHandler = new GraphQlHttpHandler(webGraphQlHandler);
		RequestPredicate graphQlPredicate = GraphQlRequestPredicates.graphQlHttp("/graphql");
		GraphiQlHandler graphiQlHandler = new GraphiQlHandler("/graphql", "");
		return RouterFunctions.route() (5)
				.route(graphQlPredicate, graphQlHttpHandler::handleRequest)
				.GET("/graphiql", graphiQlHandler::handleRequest)
				.build();
	}
}

1	The `AnnotatedControllerConfigurer` bean is responsible for detecting GraphQL `@Controller` handlers.
2	The `ExecutionGraphQlService` processes GraphQL requests in a transport-agnostic fashion.
3	The `GraphQlSource` builder is the main configuration point. Explore its API for more options.
4	The `RouterFunction` exposes the GraphQL routes as functional endpoints.
5	You can then expose various transports (WebSocket, SSE, HTTP) over different routes.

Spring for GraphQL offers many other options and integrations with Spring projects. For more on this, you can explore the Spring Boot auto-configurations.