Support for custom BatchHandlerMethodArgumentResolver

See spring-projectsgh-298

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/support/AnnotatedControllerConfigurer.java

@@ -122,6 +122,9 @@ public class AnnotatedControllerConfigurer
 	@Nullable
 	private HandlerMethodArgumentResolverComposite argumentResolvers;
 
+	@Nullable
+	private List<BatchHandlerMethodArgumentResolver> customBatchMethodArgumentResolvers;
+
 	@Nullable
 	private BatchHandlerMethodArgumentResolverComposite batchMethodArgumentResolvers;
 
@@ -152,6 +155,22 @@ public void setConversionService(ConversionService conversionService) {
 		this.conversionService = (FormattingConversionService) conversionService;
 	}
 
+	/**
+	 * Provide resolvers for custom batch method argument types. Custom resolvers
+	 * are ordered after built-in ones.
+	 */
+	public void setCustomBatchMethodArgumentResolvers(@Nullable List<BatchHandlerMethodArgumentResolver> customBatchMethodArgumentResolvers) {
+		this.customBatchMethodArgumentResolvers = customBatchMethodArgumentResolvers;
+	}
+
+	/**
+	 * Return the custom custom batch method argument resolvers, or {@code null}.
+	 */
+	@Nullable
+	public List<BatchHandlerMethodArgumentResolver> getCustomBatchMethodArgumentResolvers() {
+		return this.customBatchMethodArgumentResolvers;
+	}
+
 	@Override
 	public void setApplicationContext(ApplicationContext applicationContext) {
 		this.applicationContext = applicationContext;
@@ -222,6 +241,11 @@ private List<BatchHandlerMethodArgumentResolver> getBatchMethodDefaultArgumentRe
 		if (springSecurityPresent) {
 			resolvers.add(new PrincipalBatchMethodArgumentResolver());
 		}
+
+		// Custom batch method argument resolvers
+		if (getCustomBatchMethodArgumentResolvers() != null) {
+			resolvers.addAll(getCustomBatchMethodArgumentResolvers());
+		}
 		return resolvers;
 	}