added ability to provide raw batch loader classes to BatchLoaderRegis…

…try alongside BiFunction registration methods. resolves spring-projects#870 & spring-projects#869

spring-graphql/src/main/java/org/springframework/graphql/execution/BatchLoaderContextProviderFactory.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2002-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.graphql.execution;
+
+import org.dataloader.BatchLoaderContextProvider;
+
+import graphql.GraphQLContext;
+
+/**
+ * Contract to create a {@link BatchLoaderContextProvider} for a given
+ * {@link GraphQLContext}.
+ */
+public interface BatchLoaderContextProviderFactory {
+
+    /**
+     * Create a new {@link BatchLoaderContextProvider} for the given
+     * {@link GraphQLContext}.
+     */
+    BatchLoaderContextProvider create(GraphQLContext context);
+}