Upgrade to Spring for GraphQL 1.3 and use built-in federation support (#80)

Spring for GraphQL 1.3 adds [built-in federation support](https://spring.io/blog/2024/02/21/spring-for-graphql-1-3-m1-released#apollo-federation) with annotated, controller methods. This PR contains the changes to switch to the built-in support. Also some minor refactoring.

I know 1.3 is not due until May 21, and Spring Boot 3.3 until May 23, but I wanted to have the changes ready and make sure all works as expected. For now this is based on release candidates.

Author: rstoyanchev

products-subgraph/build.gradle.kts

@@ -1,7 +1,7 @@
 import org.springframework.boot.gradle.tasks.bundling.BootJar
 
 plugins {
-	id("org.springframework.boot") version "3.1.4"
+	id("org.springframework.boot") version "3.3.0-RC1"
 	id("io.spring.dependency-management") version "1.1.3"
 	java
 }
@@ -11,6 +11,7 @@ version = "0.0.1-SNAPSHOT"
 
 repositories {
 	mavenCentral()
+    maven("https://repo.spring.io/milestone")
 }
 
 val federation_jvm_version: String = project.property("federation-jvm.version").toString()

products-subgraph/src/main/java/com/example/products/GraphQLConfiguration.java

@@ -2,6 +2,9 @@
 
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.autoconfigure.graphql.GraphQlSourceBuilderCustomizer;
+import org.springframework.context.annotation.Bean;
+import org.springframework.graphql.data.federation.FederationSchemaFactory;
 
 @SpringBootApplication
 public class ProductsApplication {
@@ -10,4 +13,14 @@ public static void main(String[] args) {
 		SpringApplication.run(ProductsApplication.class, args);
 	}
 
+  @Bean
+  public GraphQlSourceBuilderCustomizer customizer(FederationSchemaFactory factory) {
+    return builder -> builder.schemaFactory(factory::createGraphQLSchema);
+  }
+
+  @Bean
+  FederationSchemaFactory federationSchemaFactory() {
+    return new FederationSchemaFactory();
+  }
+
 }

products-subgraph/src/main/java/com/example/products/ProductsApplication.java

@@ -1,34 +1,25 @@
 package com.example.products;
 
+import java.util.List;
+
 import com.example.products.model.Product;
+import com.example.products.model.ProductSource;
+
 import org.springframework.graphql.data.method.annotation.Argument;
 import org.springframework.graphql.data.method.annotation.QueryMapping;
 import org.springframework.stereotype.Controller;
 
-import java.util.List;
-import java.util.Map;
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
-
 @Controller
 public class ProductsController {
 
-  private final Map<String, Product> PRODUCTS = Stream.of(
-    new Product("1","Saturn V", "The Original Super Heavy-Lift Rocket!"),
-    new Product("2","Lunar Module"),
-    new Product("3","Space Shuttle"),
-    new Product("4","Falcon 9", "Reusable Medium-Lift Rocket"),
-    new Product("5","Dragon", "Reusable Medium-Lift Rocket"),
-    new Product("6","Starship", "Super Heavy-Lift Reusable Launch Vehicle")
-  ).collect(Collectors.toMap(Product::id, product -> product));
-
   @QueryMapping
-  public Product product(@Argument String id) {
-    return PRODUCTS.get(id);
+  public Product product(@Argument Long id) {
+    return ProductSource.getProduct(id);
   }
 
   @QueryMapping
   public List<Product> products() {
-    return PRODUCTS.values().stream().toList();
+    return ProductSource.getProducts();
   }
+
 }

products-subgraph/src/main/java/com/example/products/ProductsController.java

@@ -7,9 +7,9 @@
  *     description: String
  * }
  */
-public record Product(String id, String name, String description) {
+public record Product(Long id, String name, String description) {
 
-  public Product(String id, String name) {
+  public Product(Long id, String name) {
     this(id, name, null);
   }
 }

products-subgraph/src/main/java/com/example/products/model/Product.java

@@ -0,0 +1,29 @@
+package com.example.products.model;
+
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+public final class ProductSource {
+
+  private static final List<Product> productList = List.of(
+    new Product(1L, "Saturn V", "The Original Super Heavy-Lift Rocket!"),
+    new Product(2L, "Lunar Module"),
+    new Product(3L, "Space Shuttle"),
+    new Product(4L, "Falcon 9", "Reusable Medium-Lift Rocket"),
+    new Product(5L, "Dragon", "Reusable Medium-Lift Rocket"),
+    new Product(6L, "Starship", "Super Heavy-Lift Reusable Launch Vehicle")
+  );
+
+  private static final Map<Long, Product> productMap =
+    productList.stream().collect(Collectors.toMap(Product::id, product -> product));
+
+  public static Product getProduct(Long id) {
+    return productMap.get(id);
+  }
+
+  public static List<Product> getProducts() {
+    return productList;
+  }
+
+}

products-subgraph/src/main/java/com/example/products/model/ProductSource.java

@@ -2,3 +2,6 @@ spring:
   graphql:
     graphiql:
       enabled: true
+logging:
+  level:
+    org.springframework.graphql: DEBUG

products-subgraph/src/main/resources/application.yml

@@ -33,6 +33,6 @@ query ProductById($productId: ID!) {
       .execute()
       .path("product")
       .entity(Product.class)
-      .isEqualTo(new Product("1","Saturn V", "The Original Super Heavy-Lift Rocket!"));
+      .isEqualTo(new Product(1L,"Saturn V", "The Original Super Heavy-Lift Rocket!"));
   }
 }

products-subgraph/src/test/java/com/example/products/ProductsApplicationTest.java

@@ -1,7 +1,7 @@
 import org.springframework.boot.gradle.tasks.bundling.BootJar
 
 plugins {
-	id("org.springframework.boot") version "3.1.4"
+	id("org.springframework.boot") version "3.3.0-RC1"
 	id("io.spring.dependency-management") version "1.1.3"
 	java
 }
@@ -11,6 +11,7 @@ version = "0.0.1-SNAPSHOT"
 
 repositories {
 	mavenCentral()
+    maven("https://repo.spring.io/milestone")
 }
 
 val federation_jvm_version: String = project.property("federation-jvm.version").toString()