GH-3994: Register native hints for Graph model (#3996)

Fixes https://github.com/spring-projects/spring-integration/issues/3994

Essentially, migrate those hints from Spring Boot Actuator:
an `IntegrationGraphServer` can be used without Spring Boot

* Introduce `IntegrationGraphRuntimeHints` - implementation of `RuntimeHintsRegistrar`
to register reflection hints for `Graph` and top-level `IntegrationNode` types.
* Use `@ImportRuntimeHints` on the `IntegrationGraphServer` to make those hints
conditional.

spring-integration-core/src/main/java/org/springframework/integration/graph/IntegrationGraphRuntimeHints.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2023 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.integration.graph;
+
+import org.springframework.aot.hint.BindingReflectionHintsRegistrar;
+import org.springframework.aot.hint.RuntimeHints;
+import org.springframework.aot.hint.RuntimeHintsRegistrar;
+
+/**
+ * The {@link RuntimeHintsRegistrar} implementation for {@link Graph}
+ * (and related types) reflection hints registration.
+ *
+ * @author Artem Bilan
+ *
+ * @since 6.0.3
+ */
+class IntegrationGraphRuntimeHints implements RuntimeHintsRegistrar {
+
+	@Override
+	public void registerHints(RuntimeHints hints, ClassLoader classLoader) {
+		new BindingReflectionHintsRegistrar()
+				.registerReflectionHints(hints.reflection(),
+						Graph.class,
+						ErrorCapableCompositeMessageHandlerNode.class,
+						ErrorCapableDiscardingMessageHandlerNode.class,
+						ErrorCapableMessageHandlerNode.class,
+						ErrorCapableRoutingNode.class,
+						MessageGatewayNode.class,
+						MessageProducerNode.class,
+						MessageSourceNode.class,
+						PollableChannelNode.class);
+	}
+
+}

spring-integration-core/src/main/java/org/springframework/integration/graph/IntegrationGraphServer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2022 the original author or authors.
+ * Copyright 2016-2023 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.
@@ -34,6 +34,7 @@ import org.springframework.beans.BeansException;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationContextAware;
 import org.springframework.context.ApplicationListener;
+import org.springframework.context.annotation.ImportRuntimeHints;
 import org.springframework.context.event.ContextRefreshedEvent;
 import org.springframework.integration.core.MessageSource;
 import org.springframework.integration.endpoint.IntegrationConsumer;
@@ -64,6 +65,7 @@ import org.springframework.messaging.PollableChannel;
  * @since 4.3
  *
  */
+@ImportRuntimeHints(IntegrationGraphRuntimeHints.class)
 public class IntegrationGraphServer implements ApplicationContextAware, ApplicationListener<ContextRefreshedEvent> {
 
 	private static final float GRAPH_VERSION = 1.2f;

spring-integration-core/src/test/java/org/springframework/integration/graph/IntegrationGraphServerTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2022 the original author or authors.
+ * Copyright 2016-2023 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.
@@ -33,11 +33,13 @@ import net.minidev.json.JSONArray;
 import org.assertj.core.api.InstanceOfAssertFactories;
 import org.junit.jupiter.api.Test;
 
+import org.springframework.beans.factory.ListableBeanFactory;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.SmartLifecycle;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.ImportResource;
+import org.springframework.context.annotation.ImportRuntimeHints;
 import org.springframework.expression.spel.standard.SpelExpressionParser;
 import org.springframework.integration.annotation.Filter;
 import org.springframework.integration.annotation.InboundChannelAdapter;
@@ -91,6 +93,9 @@ import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
 @DirtiesContext
 public class IntegrationGraphServerTests {
 
+	@Autowired
+	private ListableBeanFactory beanFactory;
+
 	@Autowired
 	private IntegrationGraphServer server;
 
@@ -238,6 +243,8 @@ public class IntegrationGraphServerTests {
 		assertThat(serviceActivator)
 				.containsEntry("integrationPatternType", "service_activator")
 				.containsEntry("integrationPatternCategory", "messaging_endpoint");
+
+		assertThat(this.beanFactory.findAnnotationOnBean("server", ImportRuntimeHints.class)).isNotNull();
 	}
 
 	@Test

spring-integration-http/src/test/java/org/springframework/integration/http/management/IntegrationGraphControllerTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2022 the original author or authors.
+ * Copyright 2016-2023 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.
@@ -23,6 +23,7 @@ import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.ImportRuntimeHints;
 import org.springframework.context.support.ClassPathXmlApplicationContext;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatus;
@@ -77,6 +78,8 @@ public class IntegrationGraphControllerTests {
 
 	@Test
 	public void testIntegrationGraphGet() throws Exception {
+		assertThat(this.wac.findAnnotationOnBean("integrationGraphServer", ImportRuntimeHints.class)).isNotNull();
+
 		this.mockMvc.perform(get("/testIntegration")
 						.header(HttpHeaders.ORIGIN, "https://foo.bar.com")
 						.accept(MediaType.APPLICATION_JSON))
@@ -96,6 +99,7 @@ public class IntegrationGraphControllerTests {
 		ConfigurableApplicationContext context = new ClassPathXmlApplicationContext(
 				"IntegrationGraphControllerParserTests-context.xml", getClass());
 
+		assertThat(context.findAnnotationOnBean("integrationGraphServer", ImportRuntimeHints.class)).isNotNull();
 
 		HandlerMapping handlerMapping =
 				context.getBean(RequestMappingHandlerMapping.class.getName(), HandlerMapping.class);