From a4ac531c4a732aa28597d8480bb86601575d05cc Mon Sep 17 00:00:00 2001
From: Kicey <57286603+Kicey@users.noreply.github.com>
Date: Wed, 2 Nov 2022 22:19:37 +0800
Subject: [PATCH] GH-3931: Fix meta-annotation support for @Gateway

Fixes https://github.com/spring-projects/spring-integration/issues/3931

* Update test for @AliasFor support.

**Cherry-pick to `5.5.x`**
---
 .../gateway/GatewayProxyFactoryBean.java      |  6 ++-
 .../gateway/GatewayProxyFactoryBeanTests.java | 40 +++++++++++++++++++
 2 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/spring-integration-core/src/main/java/org/springframework/integration/gateway/GatewayProxyFactoryBean.java b/spring-integration-core/src/main/java/org/springframework/integration/gateway/GatewayProxyFactoryBean.java
index 1ba8048069..f8395edb34 100644
--- a/spring-integration-core/src/main/java/org/springframework/integration/gateway/GatewayProxyFactoryBean.java
+++ b/spring-integration-core/src/main/java/org/springframework/integration/gateway/GatewayProxyFactoryBean.java
@@ -49,6 +49,7 @@ import org.springframework.beans.factory.FactoryBean;
 import org.springframework.core.KotlinDetector;
 import org.springframework.core.MethodParameter;
 import org.springframework.core.ResolvableType;
+import org.springframework.core.annotation.AnnotatedElementUtils;
 import org.springframework.core.convert.ConversionService;
 import org.springframework.core.task.AsyncTaskExecutor;
 import org.springframework.core.task.SimpleAsyncTaskExecutor;
@@ -105,6 +106,7 @@ import reactor.core.publisher.Mono;
  * @author Oleg Zhurakousky
  * @author Gary Russell
  * @author Artem Bilan
+ * @author JingPeng Xie
  */
 public class GatewayProxyFactoryBean<T> extends AbstractEndpoint
 		implements TrackableComponent, FactoryBean<T>, MethodInterceptor, BeanClassLoaderAware,
@@ -478,7 +480,7 @@ public class GatewayProxyFactoryBean<T> extends AbstractEndpoint
 		Method[] methods = ReflectionUtils.getUniqueDeclaredMethods(this.serviceInterface);
 		for (Method method : methods) {
 			if (Modifier.isAbstract(method.getModifiers())
-					|| method.getAnnotation(Gateway.class) != null
+					|| AnnotatedElementUtils.isAnnotated(method, Gateway.class)
 					|| (method.isDefault() && this.proxyDefaultMethods)) {
 
 				MethodInvocationGateway gateway = createGatewayForMethod(method);
@@ -693,7 +695,7 @@ public class GatewayProxyFactoryBean<T> extends AbstractEndpoint
 	}
 
 	private MethodInvocationGateway createGatewayForMethod(Method method) {
-		Gateway gatewayAnnotation = method.getAnnotation(Gateway.class);
+		Gateway gatewayAnnotation = AnnotatedElementUtils.findMergedAnnotation(method, Gateway.class);
 		GatewayMethodMetadata methodMetadata = null;
 		if (!CollectionUtils.isEmpty(this.methodMetadataMap)) {
 			methodMetadata = this.methodMetadataMap.get(method.getName());
diff --git a/spring-integration-core/src/test/java/org/springframework/integration/gateway/GatewayProxyFactoryBeanTests.java b/spring-integration-core/src/test/java/org/springframework/integration/gateway/GatewayProxyFactoryBeanTests.java
index cccac95309..9bf0bd44a3 100644
--- a/spring-integration-core/src/test/java/org/springframework/integration/gateway/GatewayProxyFactoryBeanTests.java
+++ b/spring-integration-core/src/test/java/org/springframework/integration/gateway/GatewayProxyFactoryBeanTests.java
@@ -23,6 +23,10 @@ import static org.mockito.BDDMockito.willReturn;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.spy;
 
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
 import java.lang.reflect.Method;
 import java.util.Collections;
 import java.util.Map;
@@ -40,6 +44,7 @@ import org.springframework.beans.factory.BeanInitializationException;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.support.DefaultListableBeanFactory;
 import org.springframework.context.support.ClassPathXmlApplicationContext;
+import org.springframework.core.annotation.AliasFor;
 import org.springframework.core.convert.converter.Converter;
 import org.springframework.core.convert.support.DefaultConversionService;
 import org.springframework.core.convert.support.GenericConversionService;
@@ -70,6 +75,7 @@ import org.springframework.util.ReflectionUtils;
  * @author Gunnar Hillert
  * @author Gary Russell
  * @author Artem Bilan
+ * @author JingPeng Xie
  */
 public class GatewayProxyFactoryBeanTests {
 
@@ -496,6 +502,20 @@ public class GatewayProxyFactoryBeanTests {
 		assertThat(gateways.size()).isEqualTo(2);
 	}
 
+	@Test
+	public void testAliasForSupport() throws NoSuchMethodException {
+		MessageChannel requestChannel = new DirectChannel();
+		DefaultListableBeanFactory beanFactory = new DefaultListableBeanFactory();
+		beanFactory.registerSingleton("requestChannel", requestChannel);
+		GatewayProxyFactoryBean<CompositedGatewayService> gpfb = new GatewayProxyFactoryBean<>(
+				CompositedGatewayService.class);
+		gpfb.setBeanFactory(beanFactory);
+		gpfb.afterPropertiesSet();
+		Map<Method, MessagingGatewaySupport> gateways = gpfb.getGateways();
+		Method sendMethod = CompositedGatewayService.class.getMethod("gatewayMethod");
+		assertThat(gateways.get(sendMethod).getRequestChannel()).isEqualTo(beanFactory.getBean("requestChannel"));
+	}
+
 	public static void throwTestException() throws TestException {
 		throw new TestException();
 	}
@@ -515,6 +535,26 @@ public class GatewayProxyFactoryBeanTests {
 
 	}
 
+
+	@Gateway
+	@Retention(RetentionPolicy.RUNTIME)
+	@Target(ElementType.METHOD)
+	@interface CompositedGateway {
+
+		@AliasFor(annotation = Gateway.class, attribute = "requestChannel")
+		String requestChannelName() default "";
+
+	}
+
+
+	interface CompositedGatewayService {
+
+		@CompositedGateway(requestChannelName = "requestChannel")
+		void gatewayMethod();
+
+	}
+
+
 	interface HeadersParamService {
 
 		Message<?> echo(String s, @Header(MessageHeaders.TIMESTAMP) String foo);